CN108656927B

CN108656927B - Hybrid electric vehicle and power system thereof

Info

Publication number: CN108656927B
Application number: CN201710211041.9A
Authority: CN
Inventors: 杨冬生; 王春生; 白云辉
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2017-03-31
Filing date: 2017-03-31
Publication date: 2024-04-16
Anticipated expiration: 2037-03-31
Also published as: CN108656927A

Abstract

The invention discloses a hybrid electric vehicle and a power system thereof, wherein the power system comprises: an engine that outputs power to wheels of the hybrid vehicle through a clutch; a power motor for outputting a driving force to wheels of the hybrid vehicle; the power battery is used for supplying power to the power motor; a DC-DC converter; the auxiliary motor is connected with the power motor, the DC-DC converter and the power battery respectively, and the auxiliary motor is used for at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter when the auxiliary motor is driven by the engine to generate power, so that the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained.

Description

Hybrid electric vehicle and power system thereof

Technical Field

The invention relates to the technical field of vehicles, in particular to a power system of a hybrid electric vehicle and the hybrid electric vehicle with the power system.

Background

With the continuous consumption of energy, the development and utilization of new energy vehicle types have gradually become a trend. The hybrid electric vehicle is one of new energy vehicle types, and is driven by an engine and/or a motor.

However, in the related art, the front motor of the hybrid electric vehicle is used as a driving motor and also as a generator, so that the rotation speed of the front motor is low during low-speed running, and the generated power and the generated efficiency are very low, so that the power consumption requirement of low-speed running cannot be met, and the maintenance of low-speed electric balance of the whole vehicle is relatively difficult.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, a first object of the present invention is to provide a power system of a hybrid electric vehicle, which can realize low-speed electric balance of the whole vehicle.

A second object of the present invention is to provide a hybrid vehicle.

To achieve the above object, an embodiment of a first aspect of the present invention provides a power system of a hybrid vehicle, including: an engine that outputs power to wheels of the hybrid vehicle through a clutch; a power motor for outputting a driving force to wheels of the hybrid vehicle; the power battery is used for supplying power to the power motor; a DC-DC converter; the auxiliary motor is connected with the power motor, the DC-DC converter and the power battery respectively, and the auxiliary motor is used for at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter when generating electricity under the drive of the engine.

According to the power system of the hybrid electric vehicle, disclosed by the embodiment of the invention, the engine outputs power to the wheels of the hybrid electric vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid electric vehicle, the power battery supplies power to the power motor, and the auxiliary motor is used for at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter when generating electricity under the driving of the engine, so that the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained, and the performance of the whole vehicle is improved.

To achieve the above object, a second aspect of the present invention provides a hybrid vehicle, including a power system of the hybrid vehicle.

According to the hybrid electric vehicle provided by the embodiment of the invention, the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained, and the performance of the whole vehicle is improved.

Drawings

FIG. 1 is a block schematic diagram of a powertrain of a hybrid vehicle according to an embodiment of the present invention;

fig. 2a is a schematic structural view of a power system of a hybrid vehicle according to an embodiment of the present invention;

fig. 2b is a schematic structural view of a power system of a hybrid vehicle according to another embodiment of the present invention;

FIG. 3 is a block schematic diagram of a powertrain of a hybrid vehicle according to one embodiment of the present invention;

FIG. 4 is a schematic illustration of a transmission between an engine and corresponding wheels in accordance with one embodiment of the present disclosure;

FIG. 5 is a schematic illustration of a transmission arrangement between an engine and corresponding wheels in accordance with another embodiment of the present invention;

FIG. 6 is a block schematic diagram of a powertrain of a hybrid vehicle according to another embodiment of the present invention;

FIG. 7 is a graphical representation of the universal behavior of an engine according to one embodiment of the present invention;

FIG. 8 is a block diagram of a powertrain of a hybrid vehicle according to one embodiment of the present invention;

fig. 9a is a schematic structural view of a power system of a hybrid vehicle according to an embodiment of the present invention;

fig. 9b is a schematic structural view of a power system of a hybrid vehicle according to another embodiment of the present invention;

fig. 9c is a schematic structural view of a power system of a hybrid vehicle according to still another embodiment of the present invention;

FIG. 10 is a block diagram of a voltage regulator circuit according to one embodiment of the invention;

FIG. 11 is a schematic diagram of a voltage regulation control according to one embodiment of the invention;

FIG. 12 is a block diagram of a powertrain of a hybrid vehicle according to one embodiment of the present invention;

FIG. 13 is a block schematic diagram of a hybrid vehicle according to an embodiment of the invention;

fig. 14 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention;

fig. 15 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the present invention

Fig. 16 is a flowchart of a power generation control method of a hybrid vehicle according to another embodiment of the invention;

fig. 17 is a flowchart of a power generation control method of a hybrid vehicle according to another embodiment of the invention;

FIG. 18 is a mixing according to yet another embodiment of the invention a flow chart of a power generation control method of a power automobile;

fig. 19 is a flowchart of a power generation control method of a hybrid vehicle according to still another embodiment of the invention;

fig. 20 is a flowchart of a power generation control method of a hybrid vehicle according to still another embodiment of the invention;

fig. 21 is a flowchart of a power generation control method of a hybrid vehicle according to still another embodiment of the invention;

fig. 22 is a flowchart of a power generation control method of a hybrid vehicle according to still another embodiment of the invention; and

fig. 23 is a flowchart of a power generation control method of a hybrid vehicle according to still another embodiment of the invention.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

A power system of a hybrid vehicle according to an embodiment of an aspect of the present invention will be described with reference to fig. 1 to 5, the power system provides sufficient power and electric energy for normal running of the hybrid electric vehicle.

Fig. 1 is a block schematic diagram of a power system of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 1, the power system of the hybrid vehicle includes: an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4, and a sub-motor 5.

As shown in fig. 1 to 3, the engine 1 outputs power to wheels 7 of the hybrid vehicle through a clutch 6; the power motor 2 is used for outputting driving force to the wheels 7 of the hybrid vehicle. That is, the power system of the embodiment of the present invention may provide power for normal running of the hybrid vehicle through the engine 1 and/or the power motor 2. In some embodiments of the present invention, the power source of the power system may be the engine 1 and the power motor 2, that is, either one of the engine 1 and the power motor 2 may output power to the wheels 7 alone, or the engine 1 and the power motor 2 may output power to the wheels 7 at the same time.

The power battery 3 is used for supplying power to the power motor 2; the sub-motor 5 is connected to the engine 1, and for example, the sub-motor 5 may be connected to the engine 1 through a train end of the engine 1. The auxiliary motor 5 is respectively connected with the power motor 2, the DC-DC converter 4 and the power battery 3, and the auxiliary motor 5 is used for at least one of charging the power battery 3, supplying power to the power motor 2 and supplying power to the DC-DC converter 4 when generating electricity under the drive of the engine 1. In other words, the engine 1 may drive the sub-motor 5 to generate electricity, and the electric energy generated by the sub-motor 5 may be supplied to at least one of the power battery 3, the power motor 2, and the DC-DC converter 4. It should be understood that the engine 1 may drive the sub-motor 5 to generate electricity while outputting power to the wheels 7, or may drive the sub-motor 5 to generate electricity alone.

Therefore, the power motor 2 and the auxiliary motor 5 respectively correspond to serve as a driving motor and a generator, and the auxiliary motor 5 has higher power generation power and power generation efficiency when in low speed, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved.

In some embodiments, the secondary motor 5 may be a BSG (Belt-driven start/generator integrated motor) motor. The sub-motor 5 is a high-voltage motor, for example, the generated voltage of the sub-motor 5 is equal to the voltage of the power battery 3, so that the power generated by the sub-motor 5 can directly charge the power battery 3 without voltage conversion, and can also directly supply power to the power motor 2 and/or the DC-DC converter 4. The auxiliary motor 5 also belongs to a high-efficiency generator, for example, the auxiliary motor 5 is driven to generate electricity at the idle speed of the engine 1, so that the electricity generation efficiency of more than 97% can be realized.

In addition, in some embodiments of the present invention, the sub-motor 5 may be used to start the engine 1, i.e., the sub-motor 5 may have a function of starting the engine 1, for example, when starting the engine 1, the sub-motor 5 may rotate a crankshaft of the engine 1 to bring a piston of the engine 1 to an ignition position, thereby achieving the starting of the engine 1, whereby the sub-motor 5 may perform the function of a starter in the related art.

As described above, the engine 1 and the power motor 2 can both be used to drive the wheels 7 of a hybrid vehicle. For example, as shown in fig. 2a, the engine 1 and the power motor 2 drive together the same wheel of the hybrid vehicle such as a pair of front wheels 71 (including a left front wheel and a right front wheel); as another example, as shown in fig. 2b, the engine 1 may drive a first wheel of the hybrid vehicle, such as a pair of front wheels 71 (including a left front wheel and a right front wheel), and the power motor 2 may drive a second wheel of the hybrid vehicle, such as a pair of rear wheels 72 (including a left rear wheel and a right rear wheel).

In other words, when the engine 1 and the power motor 2 jointly drive the pair of front wheels 71, the driving force of the power system is output to the pair of front wheels 71, and the whole vehicle can adopt a two-drive driving mode; when the engine 1 drives the pair of front wheels 71 and the power motor 2 drives the pair of rear wheels 72, the driving force of the power system is output to the pair of front wheels 71 and the pair of rear wheels 72, respectively, and the whole vehicle can be driven by four-wheel drive.

Further, when the engine 1 and the power motor 2 drive the same wheel together, as shown in fig. 2a, the power system of the hybrid vehicle further includes a final drive 8 and a transmission 90, wherein the engine 1 outputs power to a first wheel of the hybrid vehicle, such as a pair of front wheels 71, through the clutch 6, the transmission 90 and the final drive 8, and the power motor 2 outputs driving force to the first wheel of the hybrid vehicle, such as a pair of front wheels 71, through the final drive 8. Wherein the clutch 6 and the transmission 90 may be integrally provided.

When the engine 1 drives a first wheel and the power motor 2 drives a second wheel, as shown in connection with fig. 2b, the power system of the hybrid vehicle further comprises a first transmission 91 and a second transmission 92, wherein the engine 1 outputs power to the first wheel of the hybrid vehicle, for example, a pair of front wheels 71, through the clutch 6 and the first transmission 91, and the power motor 2 outputs driving force to the second wheel of the hybrid vehicle, for example, a pair of rear wheels 72, through the second transmission 92. Wherein the clutch 6 and the first transmission 91 may be integrally provided.

Further, in some embodiments of the present invention, as shown in fig. 1 to 3, the sub-motor 5 further includes a first controller 51, the power motor 2 further includes a second controller 21, and the sub-motor 5 is connected to the power battery 3 and the DC-DC converter 4 through the first controller 51, respectively, and is connected to the power motor 2 through the first controller 51 and the second controller 21.

Specifically, the first controller 51 is connected to the second controller 21, the power battery 3, and the DC-DC converter 4, respectively, and the first controller 51 may have an AC-DC conversion unit that may generate an alternating current when the sub-motor 5 generates electricity, and the AC-DC conversion unit may convert the alternating current generated by the high voltage motor 2 into a high voltage direct current, for example, 600V high voltage direct current, to achieve at least one of charging the power battery 3, supplying power to the power motor 2, and supplying power to the DC-DC converter 4.

Similarly, the second controller 21 may have a DC-AC conversion unit, and the first controller 51 may convert the alternating current generated by the sub-motor 5 into high voltage direct current, and the DC-AC conversion unit may convert the high voltage direct current converted by the first controller 51 into alternating current to supply the power motor 2 with power.

In other words, as shown in fig. 3, when the sub-motor 5 generates power, the sub-motor 5 may charge the power battery 3 and/or supply power to the DC-DC converter 4 through the first controller 51. In addition, the sub motor 5 may also supply power to the power motor 2 through the first controller 51 and the second controller 21.

Further, as shown in fig. 1 to 3, the DC-DC converter 4 is also connected to the power battery 3. The DC-DC converter 4 is also connected to the power motor 2 via a second controller 21.

In some embodiments, as shown in fig. 3, the first controller 51 has a first DC terminal DC1, the second controller 21 has a second DC terminal DC2, the DC-DC converter 4 has a third DC terminal DC3, and the third DC terminal DC3 of the DC-DC converter 4 may be connected to the first DC terminal DC1 of the first controller 51 to DC-DC convert the high voltage DC output from the first controller 51 through the first DC terminal DC 1. And, the third DC end DC3 of the DC-DC converter 4 may be further connected to the power battery 3, and further the first DC end DC1 of the first controller 51 may be connected to the power battery 3, so that the first controller 51 outputs high voltage DC to the power battery 3 through the first DC end DC1 to charge the power battery 3. Further, the third DC end DC3 of the DC-DC converter 4 may be further connected to the second DC end DC2 of the second controller 21, and further the first DC end DC1 of the first controller 51 may be connected to the second DC end DC2 of the second controller 21, so that the first controller 51 outputs high-voltage DC to the second controller 21 through the first DC end DC1 to supply power to the power motor 2.

Further, as shown in fig. 3, the DC-DC converter 4 is also connected to the first electric device 10 and the low-voltage battery 20 in the hybrid vehicle, respectively, to supply power to the first electric device 10 and the low-voltage battery 20, and the low-voltage battery 20 is also connected to the first electric device 10.

In some embodiments, as shown in fig. 3, the DC-DC converter 4 further has a fourth DC terminal DC4, and the DC-DC converter 4 may convert the high voltage direct current output from the power battery 3 and/or the high voltage direct current output from the sub-motor 5 through the first controller 51 into the low voltage direct current and output the low voltage direct current through the fourth DC terminal DC 4. Further, the fourth DC terminal DC4 of the DC-DC converter 4 may be connected to the first electrical device 10 to supply power to the first electrical device 10, wherein the first electrical device 10 may be a low voltage electrical device, including but not limited to a car light, a radio, etc. The fourth direct current terminal DC4 of the DC-DC converter 4 may also be connected to the low voltage battery 20 for charging the low voltage battery 20.

In addition, the low-voltage storage battery 20 is connected with the first electrical equipment 10 to supply power to the first electrical equipment 10, particularly, when the auxiliary motor 5 stops generating power and the power battery 3 fails or the electric quantity is insufficient, the low-voltage storage battery 20 can supply power to the first electrical equipment 10, so that the low-voltage power consumption of the whole vehicle is ensured, the whole vehicle can realize pure fuel mode running, and the running mileage of the whole vehicle is improved.

As described above, the third direct current terminal DC3 of the DC-DC converter 4 is connected to the first controller 51, the fourth direct current terminal DC4 of the DC-DC converter 4 is connected to the first electric device 10 and the low voltage battery 20, respectively, and when the power motor 2, the second controller 21 and the power battery 3 fail, the sub-motor 5 can generate electricity to supply power to the first electric device 10 and/or charge the low voltage battery 20 through the first controller 51 and the DC-DC converter 4, so that the hybrid vehicle travels in the pure fuel mode.

In other words, when the power motor 2, the second controller 21, and the power battery 3 fail, the first controller 51 may convert the alternating current generated by the sub-motor 5 into high voltage direct current, and the DC-DC converter 4 may convert the high voltage direct current converted by the first controller 50 into low voltage direct current to power the first electrical device 10 and/or charge the low voltage storage battery 20.

Therefore, the auxiliary motor 5 and the DC-DC converter 4 have a single power supply channel, when the power motor 2, the second controller 21 and the power battery 3 fail, electric driving cannot be realized, and at the moment, the low-voltage power consumption of the whole vehicle can be ensured through the single power supply channels of the auxiliary motor 5 and the DC-DC converter 4, the whole vehicle can be ensured to realize pure fuel mode driving, and the driving mileage of the whole vehicle is improved.

With further reference to the embodiment of fig. 3, the first controller 51, the second controller 21 and the power battery 3 are also respectively connected to the second electrical device 30 in the hybrid vehicle.

In some embodiments, as shown in fig. 3, the first DC terminal DC1 of the first controller 51 may be connected to the second electrical device 30, and the sub-motor 5 may directly supply power to the second electrical device 30 through the first controller 51 when the sub-motor 5 generates power. In other words, the AC-DC conversion unit of the first controller 51 may also convert the alternating current generated by the sub-motor 5 into high voltage direct current and directly supply power to the second electric device 30.

Similarly, the power battery 3 may also be connected to the second electrical device 30 to power the second electrical device 30. That is, the high-voltage direct current output from the power battery 3 may be directly supplied to the second electrical device 30.

The second electrical device 30 may be a high voltage electrical device, and may include, but is not limited to, an air conditioning compressor, a PTC (Positive Temperature Coefficient ) heater, and the like.

As described above, by the sub-motor 5 generating electricity, it is possible to charge the power battery 3, or to supply power to the power motor 2, or to supply power to the first electric device 10 and the second electric device 30. The power battery 3 may supply power to the power motor 2 through the second controller 21, or to the second electrical device 30, or may supply power to the first electrical device 10 and/or the low-voltage battery 20 through the DC-DC converter 4. Therefore, the power supply mode of the whole vehicle is enriched, the power consumption requirement of the whole vehicle under different working conditions is met, and the performance of the whole vehicle is improved.

It should be noted that, in the embodiment of the present invention, the low voltage may refer to a voltage of 12V (volts) or 24V, and the high voltage may refer to a voltage of 600V, but is not limited thereto.

Therefore, in the power system of the hybrid electric vehicle, the engine is not involved in driving at low speed, the clutch is not used, the abrasion or sliding abrasion of the clutch is reduced, meanwhile, the setback is reduced, the comfort is improved, the engine can work in an economic area at low speed, only power generation is not performed, the oil consumption is reduced, the noise of the engine is reduced, the low-speed electric balance and the low-speed smoothness of the whole vehicle are maintained, and the performance of the whole vehicle is improved. The auxiliary motor can directly charge the power battery, can also supply power for low-voltage devices such as a low-voltage storage battery, a first electrical equipment and the like, and can also be used as a starter.

A specific embodiment of a power system of a hybrid vehicle, which is suitable for a power system in which the engine 1 and the power motor 2 drive the same wheel together, i.e., a two-drive hybrid vehicle, is described in detail below with reference to fig. 4. It should be noted that this embodiment mainly describes a specific transmission structure between the engine 1, the power motor 2 and the wheels 7, particularly the structure of the transmission 90 in fig. 2a, and the rest is substantially the same as the embodiments in fig. 1 and 3, and will not be described in detail here.

It should be further noted that a plurality of input shafts, a plurality of output shafts, and a motor power shaft 931 and associated gears and shift elements on each shaft, etc. in the following embodiments may be used to construct the transmission 90 in fig. 2 a.

In some embodiments, as shown in fig. 1, 3 and 4, the power system of the hybrid vehicle mainly includes an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4, a sub-motor 5, a plurality of input shafts (e.g., a first input shaft 911, a second input shaft 912), a plurality of output shafts (e.g., a first output shaft 921, a second output shaft 922), and a motor power shaft 931 and associated gears on each shaft, and a shift element (e.g., a synchronizer).

As shown in figure 4 of the drawings, the engine 1 outputs power to wheels 7 of a hybrid vehicle through a clutch 6 such as a double clutch 2d in the example of fig. 4. The engine 1 is arranged to selectively engage at least one of the plurality of input shafts via the double clutch 2d when power transmission is performed between the engine 1 and the input shafts. In other words, when the engine 1 transmits power to the input shafts, the engine 1 can be selectively engaged with one of the plurality of input shafts to transmit power, or the engine 1 can also be selectively engaged with two or more of the plurality of input shafts simultaneously to transmit power.

For example, in the example of fig. 4, the plurality of input shafts may include two input shafts, a first input shaft 911 and a second input shaft 912, and the second input shaft 912 may be coaxially sleeved on the first input shaft 911, and the engine 1 may be selectively engaged with one of the first input shaft 911 and the second input shaft 912 through the double clutch 2d to transmit power. Alternatively, in particular, the engine 1 can also be engaged simultaneously with the first input shaft 911 and the second input shaft 912 to transmit power. Of course, it should be appreciated that the engine 1 may also be disconnected from both the first input shaft 911 and the second input shaft 912.

The plurality of output shafts may include two output shafts of a first output shaft 921 and a second output shaft 922, and the first output shaft 921 and the second output shaft 922 are disposed in parallel with the first input shaft 911.

The input shaft and the output shaft can be driven by a gear pair. For example, a gear driving gear is disposed on each input shaft, that is, a gear driving gear is disposed on each input shaft of the first input shaft 911 and the second input shaft 912, a gear driven gear is disposed on each output shaft, that is, a gear driven gear is disposed on each output shaft of the first output shaft 921 and the second output shaft 922, and the gear driven gears are correspondingly engaged with the gear driving gears, thereby forming a gear pair with a plurality of pairs of different speed ratios.

In some embodiments of the present invention, a six-speed transmission may be employed between the input shaft and the output shaft, i.e., with a first gear pair, a second gear pair, a third gear pair, a fourth gear pair, a fifth gear pair, and a sixth gear pair. However, the present invention is not limited thereto, and it is possible for those skilled in the art to adaptively increase or decrease the number of gear pairs according to the transmission requirement, and is not limited to the six-speed transmission shown in the embodiment of the present invention.

As shown in fig. 4, the motor power shaft 931 is provided so as to be interlocked with one of a plurality of output shafts (e.g., a first output shaft 921, a second output shaft 922), and the motor power shaft 931 is interlocked with the one of the output shafts so that power can be transmitted between the motor power shaft 931 and the one of the output shafts. For example, power via the output shaft (such as power output from the engine 1) may be output to the motor power shaft 931, or power via the motor power shaft 931 (such as power output from the power motor 2) may be output to the output shaft.

It should be noted that "linkage" is understood to mean that a plurality of components (e.g., two) move in association with each other, and two components are taken as an example, and when one of the components moves, the other component also moves.

For example, in some embodiments of the invention, a gear in conjunction with a shaft may be understood to mean that the shaft in conjunction with the gear will also rotate as the gear rotates, or that the gear in conjunction with the shaft will also rotate as the shaft rotates.

As another example, a shaft-to-shaft linkage may be understood as when one of the shafts rotates, the other shaft with which it is linked will also rotate.

For another example, gear-to-gear linkage may be understood as when one of the gears rotates, the other gear with which it is linked will also rotate.

In the following description of the invention with respect to "linkage", this is understood unless specifically indicated.

Similarly, the power motor 2 is provided so as to be able to be interlocked with the motor power shaft 931, for example, the power motor 2 may output the generated power to the motor power shaft 931, thereby outputting the driving force to the wheels 7 of the hybrid vehicle through the motor power shaft 931.

It should be noted that, in the description of the present invention, the motor power shaft 931 may be the motor shaft of the power motor 2 itself. Of course, it is understood that the motor power shaft 931 and the motor shaft of the power motor 2 may be two separate shafts.

In some embodiments, as shown in fig. 4, the output 221 is differentially rotatable relative to the one of the output shafts (e.g., the second output shaft 922), in other words, the output 221 and the output shaft are independently rotatable at different rotational speeds.

Further, the output portion 221 is provided to be selectively engageable with the one of the output shafts to rotate in synchronization therewith, in other words, the output portion 221 is capable of differential rotation or synchronous rotation with respect to the output shaft. In short, the output 221 is engageable for synchronous rotation with respect to the one of the output shafts, but may of course be disengageable for differential rotation.

As shown in fig. 4, the output part 221 may be provided on the one of the output shafts without being limited thereto. For example, in the example of fig. 4, the output part 221 is sleeved on the second output shaft 922, that is, the output part 221 and the second output shaft 922 can rotate at different rotational speeds in a differential manner.

As described above, the output unit 221 can be rotated in synchronization with the one of the output shafts, and for example, the synchronization between the output unit 221 and the output shaft can be achieved by adding a corresponding synchronizer when necessary. The synchronizer may be an output synchronizer 221c, the output synchronizer 221c being arranged for synchronizing said one of the output 221 and the output shaft.

In some embodiments, the power motor 2 is configured to output driving force to wheels 7 of the hybrid vehicle, and the engine 1 and the power motor 2 jointly drive the same wheels of the hybrid vehicle. In connection with the example of fig. 4, a differential 75 of the vehicle may be disposed between the pair of front wheels 71 or between the pair of rear wheels 72, and in some examples of the invention, the differential 75 may be located between the pair of front wheels 71 when the power motor 2 drives the pair of front wheels 71.

The differential 75 functions to roll the left and right drive wheels at different angular speeds when the vehicle is traveling around a curve or on uneven ground to ensure pure rolling movement between the drive wheels on both sides and the ground. The differential 75 is provided with a final drive driven gear 74 of the final drive 8, for example, the final drive driven gear 74 may be disposed on a housing of the differential 75. The final drive driven gear 74 may be, but is not limited to, a bevel gear.

In some embodiments, as shown in fig. 1, a power battery 3 is used to power the power motor 2; the auxiliary motor 5 is connected with the engine 1, the auxiliary motor 5 is also respectively connected with the power motor 2, the DC-DC converter 4 and the power battery 3, and the auxiliary motor 5 is used for at least one of charging the power battery 3, supplying power to the power motor 2 and supplying power to the DC-DC converter 4 when generating electricity under the drive of the engine 1.

Another specific embodiment of the power system of the hybrid vehicle, which is equally applicable to a power system in which the engine 1 and the power motor 2 drive the same wheel together, i.e., a two-drive hybrid vehicle, is described in detail below with reference to fig. 5. It should be noted that this embodiment mainly describes a specific transmission structure between the engine 1, the power motor 2 and the wheels 7, particularly the structure of the transmission 90 in fig. 2a, and the rest is substantially the same as the embodiments in fig. 1 and 3, and will not be described in detail here.

In some embodiments, as shown in fig. 1, 3 and 5, the power system of the hybrid vehicle mainly includes an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4, a sub-motor 5, a plurality of input shafts (e.g., a first input shaft 911, a second input shaft 912), a plurality of output shafts (e.g., a first output shaft 921, a second output shaft 922), and a motor power shaft 931 and associated gears on each shaft, and a shift element (e.g., a synchronizer).

As shown in fig. 5, the engine 1 outputs power to wheels 7 of a hybrid vehicle through a clutch 6 such as a double clutch 2d in the example of fig. 4. The engine 1 is arranged to selectively engage at least one of the plurality of input shafts via the double clutch 2d when power transmission is performed between the engine 1 and the input shafts. In other words, when the engine 1 transmits power to the input shafts, the engine 1 can be selectively engaged with one of the plurality of input shafts to transmit power, or the engine 1 can also be selectively engaged with two or more of the plurality of input shafts simultaneously to transmit power.

For example, in the example of fig. 5, the plurality of input shafts may include two input shafts, a first input shaft 911 and a second input shaft 912, the second input shaft 912 being coaxially sleeved on the first input shaft 911, and the engine 1 being capable of selectively engaging with one of the first input shaft 911 and the second input shaft 912 through the double clutch 2d to transmit power. Alternatively, in particular, the engine 1 can also be engaged simultaneously with the first input shaft 911 and the second input shaft 912 to transmit power. Of course, it should be appreciated that the engine 1 may also be disconnected from both the first input shaft 911 and the second input shaft 912.

As shown in fig. 5, at least one reverse output gear 81 is provided to a hollow sleeve of one of the output shafts (e.g., the first output shaft 921 and the second output shaft 922), and a reverse synchronizer (e.g., the five-gear synchronizer 5c, the six-gear synchronizer 6 c) for engaging the reverse output gear 81 is further provided thereto, in other words, the reverse synchronizer synchronizes the corresponding reverse output gear 81 and the output shaft, so that the output shaft and the reverse output gear 81 synchronized by the reverse synchronizer can be rotated in synchronization, and reverse power can be output from the output shaft.

In some embodiments, as shown in fig. 5, the reverse output gear 81 is one, and the one reverse output gear 81 may be sleeved on the second output shaft 922. However, the present invention is not limited thereto, and in other embodiments, the number of the reverse gear output gears 81 may be two, and the two reverse gear output gears 81 may be simultaneously sleeved on the second output shaft 922. Of course, it is understood that three or more reverse output gears 81 may be provided.

The reverse gear shaft 89 is provided to be interlocked with one of the input shafts (e.g., the first input shaft 911 and the second input shaft 912) and also interlocked with at least one reverse gear output gear 81, for example, power on the one of the input shafts may be transmitted to the reverse gear output gear 81 through the reverse gear shaft 89, so that reverse gear power can be output from the reverse gear output gear 81. In the example of the present invention, the reverse gear output gears 81 are all sleeved on the second output shaft 922, and the reverse gear shaft 89 is linked with the first input shaft 911, for example, the reverse gear power output by the engine 1 can be output to the reverse gear output gears 81 after passing through the first input shaft 911 and the reverse gear shaft 89.

The motor power shaft 931 is described in detail below. The motor power shaft 931 is provided with a motor power shaft first gear 31 and a motor power shaft second gear 32 in a hollow manner. The motor power shaft first gear 31 may be engaged with the final drive driven gear 74 to transmit driving force to the wheels 7 of the hybrid vehicle.

The motor power shaft second gear 32 is arranged to be linked with one of the gear driven gears, and when the hybrid electric vehicle having the power system according to the embodiment of the invention is in certain working conditions, the power output by the power source can be transmitted between the motor power shaft second gear 32 and the gear driven gear linked therewith, and at this time, the motor power shaft second gear 32 is linked with the gear driven gear. For example, the motor power shaft second gear 32 is linked with the second-gear driven gear 2b, and the motor power shaft second gear 32 and the second-gear driven gear 2b may be directly meshed or indirectly driven through an intermediate transmission member.

Further, a motor power shaft synchronizer 33c is further provided on the motor power shaft 931, the motor power shaft synchronizer 33c being located between the motor power shaft first gear 31 and the motor power shaft second gear 32, the motor power shaft synchronizer 33c being capable of selectively engaging the motor power shaft first gear 31 or the motor power shaft second gear 32 with the motor power shaft 3. For example, in the example of fig. 5, movement of the engagement sleeve of the motor-power-shaft synchronizer 33c to the left may engage the motor-power-shaft second gear 32, movement to the right may engage the motor-power-shaft first gear 31.

Since the motor power shaft first gear 31 is engaged with the final drive driven gear 74, the power motor 2 can directly output the generated power from the motor power shaft first gear 31 by engaging the motor power shaft synchronizer 33c with the motor power shaft first gear 31, so that the transmission chain can be shortened, the intermediate transmission members can be reduced, and the transmission efficiency can be improved.

Next, a transmission manner of the motor power shaft 931 and the power motor 2 will be described in detail with reference to an embodiment.

In some embodiments, as shown in fig. 5, a third gear 33 of the motor power shaft is also fixedly arranged on the motor power shaft 931, and the power motor 2 is arranged to directly mesh with the third gear 33 of the motor power shaft or indirectly drive.

Further, a first motor gear 511 is provided on the motor shaft of the power motor 2, and the first motor gear 511 is driven with the motor power shaft third gear 33 through an intermediate gear 512. As another example, the power motor 2 and the motor power shaft 931 may be coaxially connected.

In some embodiments, the power motor 2 is configured to output driving force to wheels 7 of the hybrid vehicle, and the engine 1 and the power motor 2 jointly drive the same wheels of the hybrid vehicle. In connection with the example of fig. 5, a differential 75 of the vehicle may be disposed between a pair of front wheels 71 or a pair of rear wheels 72, and in some examples of the invention, the differential 75 may be located between a pair of front wheels 71 when the power motor 2 drives the pair of front wheels 71.

Further, a first output shaft output gear 211 is fixedly arranged on the first output shaft 921, the first output shaft output gear 211 rotates synchronously with the first output shaft 921, and the first output shaft output gear 211 is meshed with the final drive driven gear 74 for transmission, so that power through the first output shaft 921 can be transmitted from the first output shaft output gear 211 to the final drive driven gear 74 and the differential 75.

Similarly, a second output shaft output gear 212 is fixedly arranged on the second output shaft 922, the second output shaft output gear 212 rotates synchronously with the second output shaft 922, and the second output shaft output gear 212 is meshed with the final drive driven gear 74 for transmission, so that power through the second output shaft 922 can be transmitted from the second output shaft output gear 212 to the final drive driven gear 74 and the differential 75.

Similarly, the motor-power-shaft first gear 31 may be used to output power via the motor-power shaft 931, so the motor-power-shaft first gear 31 is also in meshed transmission with the final drive driven gear 74.

Further, as shown in fig. 6, the power system of the hybrid electric vehicle further includes a control module 101, where the control module 101 is configured to control the power system of the hybrid electric vehicle. It should be understood that the control module 101 may be an integration of a controller having a control function in a hybrid vehicle, for example, an integration of a complete vehicle controller of the hybrid vehicle, the first controller 51 and the second controller 21 in the embodiment of fig. 3, or the like, but is not limited thereto. The control method performed by the control module 101 is described in detail below.

Embodiment one:

in some embodiments of the present invention, the control module 101 is configured to obtain an SOC value (State of Charge, also called residual Charge) of the power battery 3, an SOC value of the low-voltage battery 20, and a maximum allowable generated power of the sub-motor 5, and determine whether the sub-motor 5 charges the power battery 3 and/or the low-voltage battery 20 according to the SOC value of the power battery 3, the SOC value of the low-voltage battery 20, and the maximum allowable generated power of the sub-motor 5.

The SOC value of the power battery 3 and the SOC value of the low-voltage battery 20 may be acquired by the battery management system of the hybrid vehicle, so that the battery management system transmits the acquired SOC value of the power battery 3 and SOC value of the low-voltage battery 20 to the control module 101, so that the control module 101 acquires the SOC value of the power battery 3 and SOC value of the low-voltage battery 20.

Therefore, the power requirements of the power motor and the high-voltage electrical equipment can be ensured by charging the power battery, the power motor is further ensured to drive the whole vehicle to run normally, the power requirements of the low-voltage electrical equipment can be ensured by charging the low-voltage storage battery, the low-voltage power supply of the whole vehicle can be realized through the low-voltage storage battery when the auxiliary motor stops generating power and the power battery fails or has insufficient power, and the whole vehicle can be ensured to run in a pure fuel mode, so that the running mileage of the whole vehicle is improved.

According to a specific example of the present invention, the maximum allowable generated power of the sub-motor 5 is correlated with the performance parameters of the sub-motor 5 and the engine 1, etc., in other words, the maximum allowable generated power of the sub-motor 5 may be preset in advance in accordance with the performance parameters of the sub-motor 5 and the engine 1, etc.

Further, according to an embodiment of the present invention, the control module 101 is further configured to control the engine 1 to drive the sub-motor 5 to generate electricity to charge the power battery 3 when the SOC value of the power battery 3 is smaller than the first preset SOC value and the SOC value of the low-voltage battery 20 is greater than or equal to the second preset SOC value.

It should be understood that, the first preset SOC value may be a charging limit value of the power battery 3, the second preset SOC value may be a charging limit value of the low-voltage battery 20, and the first preset SOC value and the second preset SOC value may be set independently according to the performance of each battery in sequence, and may be the same value or different values.

Specifically, after the SOC value of the power battery 3 and the SOC value of the low-voltage battery 20 are obtained, the control module 101 may determine whether the SOC value of the power battery 3 is smaller than a first preset SOC value, and determine whether the SOC value of the low-voltage battery 20 is smaller than a second preset SOC value, if the SOC value of the power battery 3 is smaller than the first preset SOC value and the SOC value of the low-voltage battery 20 is greater than or equal to the second preset SOC value, this indicates that the remaining capacity of the power battery 3 is low, and that the remaining capacity of the low-voltage battery 20 is high, and that charging is not needed, and at this time, the control module 101 controls the engine 1 to drive the sub-motor 5 to generate power to charge the power battery 3.

As described above, the sub-motor 5 is a high-voltage motor, for example, the generated voltage of the sub-motor 5 is equivalent to the voltage of the power battery 3, so that the power generated by the sub-motor 5 can directly charge the power battery 3 without voltage conversion.

Similarly, the control module 101 is further configured to control the engine 1 to drive the sub-motor 5 to generate power to charge the low-voltage battery 20 through the DC-DC converter 4 when the SOC value of the power battery 3 is greater than or equal to the first preset SOC value and the SOC value of the low-voltage battery 20 is less than the second preset SOC value.

That is, if the SOC value of the power battery 3 is greater than or equal to the first preset SOC value and the SOC value of the low-voltage battery 20 is smaller than the second preset SOC value, it indicates that the remaining capacity of the power battery 3 is high, charging is not needed, and the remaining capacity of the low-voltage battery 20 is low, charging is needed, at this time, the control module 101 controls the engine 1 to drive the sub-motor 5 to generate power so as to charge the low-voltage battery 20 through the DC-DC converter 4.

As described above, the sub-motor 5 is a high-voltage motor, for example, the generated voltage of the sub-motor 5 corresponds to the voltage of the power battery 3, so that the electric energy generated by the sub-motor 5 needs to be voltage-converted by the DC-DC converter 4 and then charged into the low-voltage battery 20.

Still further, according to an embodiment of the present invention, the control module 101 is further configured to: when the SOC value of the power battery 3 is smaller than the first preset SOC value and the SOC value of the low-voltage battery 20 is smaller than the second preset SOC value, the charging power of the power battery 3 is obtained according to the SOC value of the power battery 3, the charging power of the low-voltage battery 20 is obtained according to the SOC value of the low-voltage battery 20, and when the sum of the charging power of the power battery 3 and the charging power of the low-voltage battery 20 is larger than the maximum allowable power generation power of the sub-motor 5, the engine 1 is controlled to drive the sub-motor 5 to generate power so as to charge the low-voltage battery 20 through the DC-DC converter 4.

And, the control module 101 is further configured to control the engine 1 to drive the sub-motor 5 to generate electricity to charge the power battery 3, and simultaneously charge the low-voltage battery 20 through the DC-DC converter 4 when the sum of the charging power of the power battery 3 and the charging power of the low-voltage battery 20 is less than or equal to the maximum allowable generated power of the sub-motor 5.

That is, if the SOC value of the power battery 3 is smaller than the first preset SOC value and the SOC value of the low-voltage battery 20 is smaller than the second preset SOC value, it is indicated that the remaining amounts of the power battery 3 and the low-voltage battery 20 are both low and charging is required, at this time, the control module 101 calculates the charging power of the power battery 3 according to the SOC value of the power battery 3, calculates the charging power of the low-voltage battery 20 according to the SOC value of the low-voltage battery 20, and further determines whether the sum of the charging power of the power battery 3 and the charging power of the low-voltage battery 20 is larger than the maximum allowable power generation of the sub-motor 5.

If the sum of the charging power of the power battery 3 and the charging power of the low-voltage storage battery 20 is greater than the maximum allowable generated power of the sub-motor 5, it is indicated that the electric energy generated by the sub-motor 5 is insufficient to charge both batteries simultaneously, and the low-voltage storage battery 20 is preferably charged at this time, that is, the engine 1 is controlled to drive the sub-motor 5 to generate electricity so as to charge the low-voltage storage battery 20 through the DC-DC converter 4.

If the sum of the charging power of the power battery 3 and the charging power of the low-voltage storage battery 20 is less than or equal to the maximum allowable generated power of the sub-motor 5, it is indicated that the electric energy generated by the sub-motor 5 can charge both batteries simultaneously, and at this time, the power battery 3 and the low-voltage storage battery 20 are charged simultaneously, i.e. the engine 1 is controlled to drive the sub-motor 5 to generate electricity to charge the power battery 3, and at the same time, the low-voltage storage battery 20 is charged through the DC-DC converter 4.

Therefore, the low-voltage storage battery is charged preferentially, so that the electricity consumption requirement of the low-voltage electrical equipment can be guaranteed preferentially, the whole vehicle can be guaranteed to realize pure fuel mode driving when the electric quantity of the power battery is insufficient, and the driving mileage of the whole vehicle is improved.

Of course, it should be understood that when the SOC value of the power battery 3 is equal to or greater than the first preset SOC value and the SOC value of the low-voltage battery 20 is equal to or greater than the second preset SOC value, it is indicated that the remaining electric power of the power battery 3 and the low-voltage battery 20 is high, and charging is not required, and the power battery 3 and the low-voltage battery 20 may not be charged at this time.

As described above, during the running of the hybrid vehicle, the control module 101 may acquire the SOC value of the power battery 3 and the SOC value of the low-voltage battery 20 in real time, and determine the SOC value of the power battery 3 and the SOC value of the low-voltage battery 20, and the determination results may be divided into the following four types:

in the first case, the remaining power of the power battery 3 is lower, and the remaining power of the low-voltage battery 20 is higher, that is, the SOC value of the power battery 3 is smaller than the first preset SOC value and the SOC value of the low-voltage battery 20 is greater than or equal to the second preset SOC value, at this time, the control module 101 controls the engine 1 to drive the sub-motor 5 to generate power so as to charge the power battery 3;

In the second case, the remaining power of the power battery 3 is higher, and the remaining power of the low-voltage battery 20 is lower, that is, the SOC value of the power battery 3 is greater than or equal to the first preset SOC value and the SOC value of the low-voltage battery 20 is smaller than the second preset SOC value, at this time, the control module 101 controls the engine 1 to drive the sub-motor 5 to generate power so as to charge the low-voltage battery 20 through the DC-DC converter 4;

in the third case, the remaining power of the power battery 3 and the remaining power of the low-voltage storage battery 20 are both lower, that is, the SOC value of the power battery 3 is smaller than the first preset SOC value and the SOC value of the low-voltage storage battery 20 is smaller than the second preset SOC value, at this time, whether to charge the power battery 3 (preferably charge the low-voltage storage battery 20) can be determined according to the maximum allowable power generation of the sub-motor 5, if the sum of the charging power of the power battery 3 and the charging power of the low-voltage storage battery 20 is greater than the maximum allowable power generation of the sub-motor 5, the power battery 3 is not charged, and only the low-voltage storage battery 20 is charged, that is, the control module 101 controls the engine 1 to drive the sub-motor 5 to generate power so as to charge the low-voltage storage battery 20 through the DC-DC converter 4; if the sum of the charging power of the power battery 3 and the charging power of the low-voltage storage battery 20 is less than or equal to the maximum allowable generated power of the auxiliary motor 5, the low-voltage storage battery 20 is charged and the power battery 3 is charged, that is, the control module 101 controls the engine 1 to drive the auxiliary motor 5 to generate electricity so as to charge the power battery 3, and simultaneously charges the low-voltage storage battery 20 through the DC-DC converter 4.

In the fourth case, the remaining amounts of the power battery 3 and the low-voltage battery 20 are both high, that is, the SOC value of the power battery 3 is equal to or greater than the first preset SOC value and the SOC value of the low-voltage battery 20 is equal to or greater than the second preset SOC value, and at this time, the power battery 3 and the low-voltage battery 20 are not charged.

In summary, according to the power system of the hybrid electric vehicle provided by the embodiment of the invention, the engine outputs power to the wheels of the hybrid electric vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid electric vehicle, the power battery supplies power to the power motor, the auxiliary motor only generates power and does not drive when the auxiliary motor is driven by the engine to generate power so as to realize at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter, and the control module judges whether the auxiliary motor charges the power battery and/or the low-voltage storage battery according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the maximum allowable power generation power of the motor, so that the engine does not participate in driving at low speed, the clutch is not used, the clutch wear or the skid is reduced, meanwhile, the low-speed feeling is reduced, the comfortableness is improved, the engine can only generate power and does not drive, the whole vehicle is reduced in oil consumption, the low-speed electric balance and the low-speed smoothness is maintained, the whole vehicle performance is improved, and the system can charge the power battery, and also charge the low-voltage storage battery, thereby ensuring that the power motor and the high-voltage power generator are not powered by the power consumption, and the power consumption of the full-vehicle is guaranteed, and the power consumption is guaranteed, and the full-speed power consumption is guaranteed, and the running mode is guaranteed, and the running mileage is guaranteed, and the running speed is and the low.

Embodiment two:

in some embodiments of the present invention, the control module 101 is configured to obtain an SOC value (State of Charge) of the power battery 3 and a vehicle speed V of the hybrid vehicle, and control the sub-motor 5 to enter the generated power adjustment mode according to the SOC value of the power battery 3 and the vehicle speed V of the hybrid vehicle, so that the engine 1 operates in a preset optimal economic area. The power generation power adjustment mode is a mode for adjusting the power generation power of the engine, and in the power generation power adjustment mode, the engine 1 can be controlled to drive the auxiliary motor 5 to generate power so as to adjust the power generation power of the auxiliary motor 5.

It should be noted that, the SOC value of the power battery 3 may be collected by the battery management system of the hybrid electric vehicle, so that the battery management system sends the collected SOC value of the power battery 3 to the control module 101, so that the control module 101 obtains the SOC value of the power battery 3.

It should also be noted that the preset optimal economic zone of the engine 1 may be determined in combination with the engine universal characteristic map. An example of an engine universal characteristic map is shown in fig. 7, in which the ordinate on the side is the output torque of the engine 1, the abscissa is the rotation speed of the engine 1, and the curve a is the fuel economy curve of the engine 1. The region corresponding to the fuel economy curve is the optimal economy region of the engine, that is, when the torque and the torque of the engine 1 are on the optimal fuel economy curve of the engine, the engine is in the optimal economy region. Thus, in an embodiment of the present invention, the control module 101 may operate the engine 1 in a preset optimal economy region by controlling the rotational speed and output torque of the engine 1 to fall on an engine fuel economy curve, such as curve a.

Specifically, during running of the hybrid vehicle, the engine 1 may output power to wheels 7 of the hybrid vehicle through the clutch 6, and the engine 1 may also drive the sub-motor 5 to generate power. The output power of the engine thus mainly includes two parts, one part being output to the sub-motor 5, i.e., the generated power that drives the sub-motor 5 to generate electricity, and the other part is the driving power that is output to the wheels 7, i.e., the driving wheels 7.

When the engine 1 drives the auxiliary motor 5 to generate power, the control module 101 may first obtain the SOC value of the power battery 3 and the speed of the hybrid vehicle, and then control the auxiliary motor 5 to enter a power generation adjustment mode according to the SOC value of the power battery 3 and the speed of the hybrid vehicle, so that the engine 1 works in a preset optimal economic area. In the generated power adjustment mode, the control module main controller 101 can adjust the generated power of the sub-motor 5 on the premise that the engine 1 is operated in a preset optimal economy area.

Thus, the engine 1 can be operated in the preset optimal economy area, since the fuel consumption of the engine 1 in the preset optimal economy area is the lowest and the fuel economy is the highest, therefore, the oil consumption of the engine 1 can be reduced, the noise of the engine 1 is reduced, and the running economy of the whole vehicle is improved. In addition, the auxiliary motor 5 has higher power generation power and power generation efficiency during low-speed running, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power battery is charged, so that the power motor and the high-voltage electrical equipment can be ensured to be required to be powered, and the power motor is further ensured to drive the whole vehicle to normally run.

Further, according to an embodiment of the present invention, the control module 101 is configured to: when the SOC value of the power battery 3 is greater than the preset limit value M2 and less than or equal to the first preset value M1, if the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, the sub-motor 5 is controlled to enter the generated power adjustment mode.

The first preset value may be an upper limit value of the SOC value of the power battery 3, which is set in advance, for example, a determination value of stopping charging, and may be preferably 30%. The preset limit value may be a preset lower limit value of the SOC value of the power battery 3, for example, a determination value of stopping the discharge, and may be preferably 10%. According to the first preset value and the preset limit value, the SOC value of the power battery 3 can be divided into three sections, namely a first electric quantity section, a second electric quantity section and a third electric quantity section, when the SOC value of the power battery 3 is smaller than or equal to the preset limit value, the SOC value of the power battery 3 is in the first electric quantity section, and at the moment, the power battery 3 is charged and not discharged; when the SOC value of the power battery 3 is larger than a preset limit value and smaller than or equal to a first preset value, the SOC value of the power battery 3 is in a second electric quantity interval, and at the moment, the power battery 3 has a charging requirement, so that the power battery 3 can be actively charged; when the SOC value of the power battery 3 is greater than the first preset value, the SOC value of the power battery 3 is in the third electric power interval, and the power battery 3 may not be charged at this time, that is, the power battery 3 may not be actively charged.

Specifically, after the control module 101 obtains the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle, it may determine a section in which the SOC value of the power battery 3 is located, if the SOC value of the power battery 3 is in the medium power section, the SOC value of the power battery 3 is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery 3 may be charged, at this time, the control module 101 further determines whether the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the auxiliary motor 5 is controlled to enter the generated power adjustment mode, at this time, the vehicle speed of the hybrid vehicle is lower, the required driving force is less, the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only drive the auxiliary motor 5 to generate power and not participate in driving.

Therefore, the engine only generates electricity and does not participate in driving at low speed, and the clutch is not needed because the engine does not participate in driving, so that the abrasion or sliding abrasion of the clutch can be reduced, the setback feeling is reduced, and the comfort is improved.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: when the SOC value of the power battery 3 is greater than the preset limit value M2 and equal to or less than the first preset value M1 and the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and acquiring the whole vehicle required power P2 of the hybrid electric vehicle, and controlling the auxiliary motor 5 to enter a power generation power regulation mode when the whole vehicle required power P2 is smaller than or equal to the maximum allowable power generation power Pmax of the auxiliary motor 5.

Specifically, during the running of the hybrid electric vehicle, if the SOC value of the power battery 3 is greater than the preset limit value M2 and less than or equal to the first preset value M1, and the vehicle speed V of the hybrid electric vehicle is less than the first preset vehicle speed V1, that is, the vehicle speed of the hybrid electric vehicle is low, the control module 101 obtains the vehicle required power P2 of the hybrid electric vehicle, and controls the sub-electric motor 5 to enter the generated power adjustment mode when the vehicle required power P2 is less than or equal to the maximum allowable generated power Pmax of the sub-electric motor 5.

Still further, according to an embodiment of the present invention, the control module 101 is further configured to obtain an accelerator pedal depth D of the hybrid vehicle and a vehicle resistance F of the hybrid vehicle when the SOC value of the power battery 3 is greater than a preset limit value and equal to or less than a first preset value M1, the vehicle speed V of the hybrid vehicle is less than a first preset vehicle speed V1, and the vehicle required power P2 of the hybrid vehicle is equal to or less than a maximum allowable power generation Pmax of the sub-motor 5, and control the sub-motor 5 to enter the power generation adjustment mode when the accelerator pedal depth D is equal to or less than the first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than the first preset resistance F1.

The vehicle resistance of the hybrid vehicle may be a driving resistance of the hybrid vehicle, such as rolling resistance, acceleration resistance, gradient resistance, air resistance, and the like.

Specifically, if the SOC value of the power battery 3 is greater than the preset limit value and equal to or less than the first preset value M1, the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and the vehicle required power P2 of the hybrid vehicle is equal to or less than the maximum allowable power generation Pmax of the sub-motor 5, the control module 101 acquires the accelerator pedal depth D of the hybrid vehicle and the vehicle resistance F of the hybrid vehicle in real time, and when the accelerator pedal depth D is equal to or less than the first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than the first preset resistance F1, the control module 101 controls the sub-motor 5 to enter the power generation adjustment mode.

As described above, when the hybrid electric vehicle runs at low speed, the engine 1 can only generate electricity and not participate in driving, and the clutch is not needed because the engine does not participate in driving, so that the clutch wear or slip wear can be reduced, meanwhile, the setback is reduced, the comfort is improved, and the engine is enabled to work in an economic area at low speed, and because the fuel consumption of the engine in a preset optimal economic area is the lowest and the fuel economy is the highest, the fuel consumption can be reduced, the engine noise is reduced, the running economy of the whole vehicle is improved, the low-speed electric balance and the low-speed smoothness of the whole vehicle are maintained, and the whole vehicle performance is improved.

Accordingly, when the SOC value of the power battery 3, the vehicle speed V, the accelerator pedal depth D, and the vehicle resistance F of the hybrid vehicle do not satisfy the above conditions, the engine 1 may participate in driving, and its specific operation is as follows.

According to one embodiment of the invention, the control module 101 is further configured to: when the SOC value of the power battery 3 is smaller than a preset limit value, or the vehicle speed of the hybrid electric vehicle is greater than or equal to a first preset vehicle speed, or the required power of the whole vehicle is greater than the maximum allowable power generation power of the auxiliary motor 5, or the depth of the accelerator pedal is greater than a first preset depth, or the whole vehicle resistance of the hybrid electric vehicle is greater than a first preset resistance, the engine 1 is controlled to participate in driving.

That is, when the SOC value of the power battery 3 is smaller than the preset limit value M2, or the vehicle speed of the hybrid vehicle is equal to or greater than the first preset vehicle speed, or the vehicle required power is greater than the maximum allowable generated power of the sub-motor 5, or the accelerator pedal depth is greater than the first preset depth, or the vehicle resistance of the hybrid vehicle is greater than the first preset resistance, the control module 101 controls the engine 1 to participate in driving, at which time the power battery 3 is no longer discharged, the driving force required for the whole vehicle is greater, the vehicle required power is greater, the accelerator pedal depth is greater, or the vehicle resistance is also greater, the power motor 2 is insufficient to drive the hybrid vehicle, and the engine 1 participates in driving to perform complementary driving.

Therefore, the engine 1 can participate in driving when the driving force output by the power motor 2 is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved.

More specifically, the control module 101 is further configured to: when the vehicle-mounted required power is greater than the maximum allowable generated power of the sub-motor 5, the engine 1 is also controlled to participate in driving so that the engine 1 outputs power to wheels through the clutch 6.

And, the control module 101 is further configured to: when the SOC value of the power battery 3 is smaller than the preset limit value M2, the engine 1 is controlled to participate in driving so that the engine 1 outputs driving force to the wheels 7 through the clutch 6; when the SOC value of the power battery 3 is equal to or less than a first preset value M1, the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and the accelerator pedal depth D is greater than a first preset depth D1, the control module 101 controls the engine 1 to participate in driving so that the engine 1 outputs power to the wheels 7 through the clutch 6; when the SOC value of the power battery 3 is equal to or less than the first preset value M1, the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and the resistance F of the hybrid vehicle is greater than the first preset resistance F1, the control module 101 controls the engine 1 to participate in driving so that the engine 1 outputs power to the wheels 7 through the clutch 6.

Specifically, when the engine 1 drives the sub motor 5 to generate power and the power motor 2 outputs driving force to the wheels 7 of the hybrid electric vehicle, the control module 101 obtains the SOC value of the power battery 3, the accelerator pedal depth D of the hybrid electric vehicle, the vehicle speed V and the vehicle resistance F in real time, and determines the SOC value of the power battery 3, the accelerator pedal depth D of the hybrid electric vehicle, the vehicle speed V and the vehicle resistance F.

First, when the SOC value of the power battery 3 is smaller than the preset limit value M2, the control module 101 controls the engine 1 to output power to the wheels 7 through the clutch 6, so that the engine 1 and the power motor 2 participate in driving at the same time, and the load of the power motor 2 is reduced to reduce the power consumption of the power battery 3, so that the engine 1 can be ensured to work in the preset optimal economic area, and the SOC value of the power battery 3 is prevented from being rapidly reduced.

Secondly, when the SOC value of the power battery 3 is less than or equal to a first preset value M1, the vehicle speed V of the hybrid electric vehicle is less than the first preset vehicle speed V1, and the accelerator pedal depth D is greater than the first preset depth D1, the control module 101 controls the engine 1 to output power to the wheels 7 through the clutch 6, so that the engine 1 and the power motor 2 participate in driving at the same time, the load of the power motor 2 is reduced to reduce the power consumption of the power battery 3, thereby ensuring that the engine 1 works in a preset optimal economic area, and avoiding the SOC value of the power battery 3 from rapidly decreasing.

Third, when the SOC value of the power battery 3 is less than or equal to the first preset value M1, the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and the resistance F of the hybrid vehicle is greater than the first preset resistance F1, the control module 101 controls the engine 1 to output power to the wheels 7 through the clutch 6, so that the engine 1 and the power motor 2 participate in driving at the same time, the load of the power motor 2 is reduced to reduce the power consumption of the power battery 3, thereby ensuring that the engine 1 works in a preset optimal economic area, and avoiding rapid decrease of the SOC value of the power battery 3.

Therefore, the engine 1 can participate in driving when the driving force output by the power motor 2 is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved. In addition, the engine can be controlled to work in an economic area, and the fuel consumption of the engine 1 in a preset optimal economic area is the lowest, so that the fuel consumption can be reduced, the engine noise can be reduced, and the economic performance of the whole vehicle can be improved.

Furthermore, the control module 101 is further configured to: when the SOC value of the power battery 3 is equal to or less than a preset limit value and the vehicle speed of the hybrid vehicle is greater than a first preset vehicle speed, the engine 1 is controlled to participate in driving so that the engine 1 outputs power to the wheels 7 through the clutch 6.

Of course, it should be understood that the control module 101 is also configured to: when the SOC value of the power battery 3 is greater than a first preset value, the engine 1 does not drive the auxiliary motor 5 to generate power, and at the moment, the electric quantity of the power battery 3 is close to full power, charging is not needed, and the engine 1 does not drive the auxiliary motor 5 to generate power. That is, when the amount of electricity of the power battery 3 is near full electricity, the engine 1 does not drive the sub-motor 5 to generate electricity, so that the sub-motor 5 does not charge the power battery 3.

Further, after the sub-motor 5 enters the generated power adjustment mode, the control module 101 may adjust the generated power of the sub-motor 5, and the generated power adjustment process of the control module 101 according to the embodiment of the present invention will be described in detail below.

In accordance with one embodiment of the present invention, the control module 101 is also configured to: after the sub motor 5 enters the generated power adjustment mode, the generated power P1 of the sub motor 5 is adjusted according to the whole vehicle required power P2 of the hybrid electric vehicle and the charging power P3 of the power battery 3.

According to one embodiment of the present invention, the formula for adjusting the generated power P1 of the sub-motor 5 according to the whole vehicle required power P2 of the hybrid vehicle and the charged power P3 of the power battery is as follows:

p1=p2+p3, wherein, p2=p11+p21,

p1 is the power generated by the auxiliary motor 5, P2 is the power required by the whole vehicle, P3 is the charging power of the power battery 3, P11 is the power driven by the whole vehicle, and P21 is the power of electrical equipment.

It should be noted that the electrical device includes the first electrical device 10 and the second electrical device 30, that is, the electrical device power P21 may include power required by the high-voltage electrical device and the low-voltage electrical device.

It should be further noted that the entire vehicle driving power P11 may include an output power of the power motor 2, and the control module 101 may obtain the entire vehicle driving power P11 according to a preset accelerator-torque curve of the power motor 2 and a rotation speed of the power motor 2, where the preset accelerator-torque curve may be determined when the power of the hybrid electric vehicle is matched. In addition, the control module 101 may obtain the electrical device power P21 in real time according to the electrical device operated by the whole vehicle, for example, calculate the electrical device power P21 through DC consumption on the bus. Further, the control module 101 may acquire the charging power P3 of the power battery 3 according to the SOC value of the power battery 3. Assuming that the vehicle drive power p11=b1 kw, the electric device power p21=b2 kw, and the charge power p3=b3 kw of the power battery 3, the generated power of the sub-motor 5=b1+b2+b3.

Specifically, during the running of the hybrid vehicle, the control module 101 may obtain the charging power P3 of the power battery 3, the entire vehicle driving power P11, and the electrical equipment power P21, and take the sum of the charging power P3 of the power battery 3, the entire vehicle driving power P11, and the electrical equipment power P21 as the generated power P1 of the sub-motor 5, so that the control module 101 may adjust the generated power of the sub-motor 5 according to the calculated P1 value, for example, the control module 101 may control the output torque and the rotation speed of the engine 1 according to the calculated P1 value, so as to adjust the power of the engine 1 driving the sub-motor 5 to generate power.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: the SOC value change rate of the power battery 3 is obtained, and the generated power P1 of the sub-motor 5 is adjusted according to the relationship between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1 and the SOC value change rate of the power battery.

It should be understood that the control module 101 may obtain the SOC value change rate of the power battery 3 according to the SOC value of the power battery 3, for example, collect the SOC value of the power battery 3 once every time interval t, so that the ratio of the difference between the current SOC value of the power battery 3 and the previous SOC value to the time interval t may be used as the SOC value change rate of the power battery 3.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after determining the minimum output power Pmin corresponding to the optimal economic region of the engine, the control module 101 may adjust the power generated by the sub-motor 5 according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1 and the SOC value change rate of the power battery 3.

Therefore, when the hybrid electric vehicle runs at a low speed, the engine is enabled to work in an economic area, so that the oil consumption can be reduced, the noise of the engine is reduced, the economical performance of the whole vehicle is improved, and when the hybrid electric vehicle runs at a low speed, the engine 1 can only generate electricity and does not participate in driving.

The specific adjustment mode of the power generation of the sub-motor 5 by the control module 101 according to the relationship between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the SOC value change rate of the power battery 3 after the sub-motor 5 enters the power generation adjustment mode will be described further below.

Specifically, when the engine 1 drives the auxiliary motor 5 to generate power and the power motor 2 outputs driving force to the wheels 7 of the hybrid electric vehicle, the whole vehicle driving power P11 and the electric equipment power P21 are obtained in real time to obtain the whole vehicle required power P2 of the hybrid electric vehicle, and the control module 101 determines the whole vehicle required power P2 of the hybrid electric vehicle, wherein the whole vehicle required power P2 can meet the following three conditions.

The first case is: the whole vehicle required power P2 is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1; the second case is: the required power P2 of the whole vehicle is larger than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine and smaller than or equal to the maximum allowable power generation power Pmax of the auxiliary motor 5; the third case is: the vehicle demand power P2 is greater than the maximum allowable power generation power Pmax of the sub-motor 5.

In one embodiment of the first case, when the vehicle required power P2 is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, the control module 101 obtains the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and determines whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the vehicle required power P2, wherein if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the vehicle required power P2, the engine 1 is controlled to generate electricity with the minimum output power Pmin to adjust the generated power P1 of the sub-motor 5; if the charging power P3 of the power battery 3 is greater than or equal to the difference between the minimum output power Pmin and the vehicle demand power P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the vehicle demand power P2, and the engine is controlled to generate electricity with the obtained output power so as to adjust the generated power P1 of the auxiliary motor 5.

It should be noted that, the first relation table between the SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3 may be pre-stored in the control module 101, and thus, after obtaining the rate of change of the SOC value of the power battery 3, the control module 101 may obtain the charging power P3 of the corresponding power battery 3 by comparing the first relationship table. The SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3 satisfy the relationship shown in table 1 below.

TABLE 1

SOC value change rate of power battery 3	A1	A2	A3	A4	A5
						Charging power P3 of power battery 3	B1	B2	B3	B4	B5

As is known from table 1, when the rate of change of the SOC value obtained by the control module 101 is A1, the obtained charging power P3 of the corresponding power battery 3 is B1; when the SOC value change rate obtained by the control module 101 is A2, the obtained charging power P3 of the corresponding power battery 3 is B2; when the SOC value change rate obtained by the control module 101 is A3, the obtained charging power P3 of the corresponding power battery 3 is B3; when the SOC value change rate obtained by the control module 101 is A4, the obtained charging power P3 of the corresponding power battery 3 is B4; when the SOC value change rate obtained by the control module 101 is A5, the obtained charging power P3 of the corresponding power battery 3 is B5.

Specifically, after the sub motor 5 enters the generated power adjustment mode, the control module 101 obtains the whole vehicle driving power P11 and the electric device power P21 in real time, so as to obtain the whole vehicle required power P2 of the hybrid electric vehicle, and determines the whole vehicle required power P2 of the hybrid electric vehicle. When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, the charging power P3 of the power battery 3 can be obtained according to the SOC value change rate of the power battery 3, and whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle is determined.

When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, namely P3 is smaller than Pmin-P2, the engine 1 is controlled to generate electricity at the minimum output power Pmin so as to regulate the generated power of the auxiliary motor 1; if the charging power P3 of the power battery 3 is greater than or equal to the difference between the minimum output power Pmin and the whole vehicle required power P2, namely, P3 is greater than or equal to Pmin-P2, the output power of the engine 1 in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the whole vehicle required power P2, and the power generation of the auxiliary motor 5 is adjusted by controlling the engine 1 to generate power according to the obtained output power.

Therefore, when the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, the generated power of the engine 1 is obtained according to the relationship between the charging power P3 of the power battery 3 and the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the required power P2 of the whole vehicle, so that the engine 1 operates in the preset optimal economic area, and the engine 1 only generates power without participating in driving, thereby reducing the fuel consumption of the engine and reducing the noise of the engine.

In one embodiment of the second case, when the vehicle-mounted required power P2 is equal to or greater than the minimum output power Pmin corresponding to the optimal economy area of the engine and equal to or less than the maximum allowable power generation Pmax of the sub-motor 5, the control module 101 obtains the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, obtains the output power of the engine 1 in the preset optimal economy area according to the sum of the charging power P3 of the power battery 3 and the vehicle-mounted required power P2, and generates power by controlling the engine 1 to generate power with the obtained output power to adjust the power generation P1 of the sub-motor 5.

Specifically, when the vehicle demand power P2 is greater than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and less than the maximum allowable generated power Pmax of the sub-motor 5, the control module 101 further obtains the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3 when controlling the engine 1 to operate in the preset optimal economic area, and obtains the output power of the engine 1 in the preset optimal economic area according to the sum of the charging power P3 of the power battery 3 and the vehicle demand power P2, where the obtained output power=p3+p2. Further, the control module 101 controls the engine 1 to generate electricity at the obtained output power to adjust the generated power P1 of the sub-motor 5, thereby increasing the SOC value of the power battery 3 and operating the engine 1 in a preset optimal economy region.

Therefore, when the required power P2 of the whole vehicle is greater than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and less than the maximum allowable power Pmax of the auxiliary motor 5, the output power of the engine 1 is obtained according to the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle, so that the engine 1 operates in the preset optimal economic area, and the engine 1 only generates power without participating in driving, thereby reducing the fuel consumption of the engine and reducing the noise of the engine.

In one embodiment of the third case, when the vehicle-mounted required power P2 is greater than the maximum allowable generated power Pmax of the sub-electric motor 5, the control module 101 also controls the engine 1 to participate in driving so that the engine 1 outputs power to the wheels 7 through the clutch 6.

Specifically, when the vehicle required power P2 is greater than the maximum allowable generated power Pmax of the sub-motor 5, that is, the vehicle required power P2 of the hybrid vehicle is greater than the generated power P1 of the sub-motor 5, the control module 101 further controls the engine 1 to output driving force to the wheels 7 through the clutch 6 to enable the engine 1 to participate in driving, so that part of the driving power P' is borne by the engine 1 to reduce the requirement for the generated power P1 of the sub-motor 5, and the engine 1 is operated in a preset optimal economic area.

Thus, when the vehicle-mounted power demand P2 is greater than the maximum allowable generated power Pmax of the sub-motor 5, the power battery 3 discharges the outside to supply power to the power motor 2, and at this time, the control module 101 controls the engine 1 and the power motor 2 to simultaneously output power to the wheels 7 of the hybrid vehicle so that the engine 1 operates in a preset optimal economic zone.

Therefore, the engine can work in an economic area at low speed, only generates electricity and does not participate in driving, so that a clutch is not used, clutch abrasion or sliding abrasion is reduced, meanwhile, the feeling of setback is reduced, the comfort is improved, the oil consumption is reduced, the noise of the engine is reduced, the low-speed electric balance and the low-speed smoothness of the whole automobile are maintained, and the performance of the whole automobile is improved.

In summary, according to the power system of the hybrid electric vehicle provided by the embodiment of the invention, the engine outputs power to the wheels of the hybrid electric vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid electric vehicle, the power battery supplies power to the power motor, the auxiliary motor generates power under the drive of the engine, the control module obtains the SOC value of the power battery and the speed of the hybrid electric vehicle, and controls the auxiliary motor to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle, so that the engine operates in a preset optimal economic area, the fuel consumption of the engine can be reduced, the running economy of the whole vehicle can be improved, the noise of the engine can be reduced, various driving modes can be realized, the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained, and the performance of the whole vehicle can be improved.

Embodiment III:

in some embodiments of the present invention, the power system of the hybrid electric vehicle further includes a control module 101, and during the running of the hybrid electric vehicle, the control module 101 is configured to obtain an SOC value (State of Charge, also called residual Charge) of the power battery 3 and a vehicle speed V of the hybrid electric vehicle, control the power generation P1 of the sub-motor 5 according to the SOC value of the power battery 3 and the vehicle speed V of the hybrid electric vehicle, and obtain the power generation P0 of the engine 1 according to the power generation P1 of the sub-motor 5 to control the engine 1 to run in a preset optimal economic area.

Specifically, during running of the hybrid vehicle, the engine 1 may output power to wheels 7 of the hybrid vehicle through the clutch 6, and the engine 1 may also drive the sub-motor 5 to generate power. Thus, the output power of the engine mainly includes two parts, one part is output to the sub motor 5, that is, the generated power for driving the sub motor 5 to generate electricity, and the other part is output to the wheels 7, that is, the driving power for driving the wheels 7.

When the engine 1 drives the auxiliary motor 5 to generate electricity, the control module 101 may first obtain the SOC value of the power battery 3 and the speed of the hybrid vehicle, then control the power P1 of the auxiliary motor 5 according to the SOC value of the power battery 3 and the speed of the hybrid vehicle, and obtain the power P0 of the engine 1 according to the power P1 of the auxiliary motor 5 to control the engine 1 to operate in a preset optimal economic area. The control module 101 may determine the power of the engine 1 driving the sub-motor 5 to generate electricity on the premise that the engine 1 is operated in a preset optimal economic area, thereby adjusting the generated power P1 of the sub-motor 5.

Therefore, the engine 1 can work in the preset optimal economic area, and the fuel consumption of the engine 1 in the preset optimal economic area is the lowest, and the fuel economy is the highest, so that the fuel consumption of the engine 1 can be reduced, the noise of the engine 1 is reduced, and the running economy of the whole vehicle is improved. In addition, the auxiliary motor 5 has higher power generation power and power generation efficiency during low-speed running, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power battery is charged, so that the power motor and the high-voltage electrical equipment can be ensured to be required to be powered, and the power motor is further ensured to drive the whole vehicle to normally run.

Further, according to an embodiment of the present invention, the control module 101 is configured to: when the SOC value of the power battery 3 is greater than the preset limit value M2 and equal to or less than the first preset value M1, the generated power P1 of the sub-motor 5 is controlled if the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1.

Specifically, after the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle are obtained, the control module 101 may determine a section in which the SOC value of the power battery 3 is located, if the SOC value of the power battery 3 is located in the medium power section, the SOC value of the power battery 3 is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery 3 may be charged, at this time, the control module 101 further determines whether the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the power generation P1 of the sub-motor 5 is controlled, at this time, the vehicle speed of the hybrid vehicle is low, the required driving force is less, the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only drive the sub-motor 5 to generate power and not participate in driving.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: when the SOC value of the power battery 3 is greater than a preset limit value M2 and less than or equal to a first preset value M1, and the vehicle speed V of the hybrid vehicle is less than a first preset vehicle speed V1, the vehicle-mounted required power P2 of the hybrid vehicle is obtained, and when the vehicle-mounted required power P2 is less than or equal to the maximum allowable power generation Pmax of the sub-motor 5, the power generation P1 of the sub-motor 5 is controlled.

Specifically, during the running of the hybrid electric vehicle, if the SOC value of the power battery 3 is greater than the preset limit value M2 and less than or equal to the first preset value M1, and the vehicle speed V of the hybrid electric vehicle is less than the first preset vehicle speed V1, that is, the vehicle speed of the hybrid electric vehicle is low, the control module 101 obtains the vehicle required power P2 of the hybrid electric vehicle, and controls the power generation P1 of the sub-electric motor 5 when the vehicle required power P2 is less than or equal to the maximum allowable power generation Pmax of the sub-electric motor 5.

Still further, according to an embodiment of the present invention, the control module 101 is further configured to obtain an accelerator pedal depth D of the hybrid vehicle and a vehicle resistance F of the hybrid vehicle when the SOC value of the power battery 3 is greater than a preset limit value and equal to or less than a first preset value M1, the vehicle speed V of the hybrid vehicle is less than a first preset vehicle speed V1, and the vehicle required power P2 of the hybrid vehicle is equal to or less than a maximum allowable power generation power Pmax of the sub-motor 5, and control the power generation power P1 of the sub-motor 5 when the accelerator pedal depth D is equal to or less than the first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than the first preset resistance F1.

Specifically, if the SOC value of the power battery 3 is greater than the preset limit value and equal to or less than the first preset value M1, the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and the vehicle required power P2 is equal to or less than the maximum allowable power generation Pmax of the sub-motor 5, the control module 101 acquires the accelerator pedal depth D of the hybrid vehicle and the vehicle resistance F of the hybrid vehicle in real time, and when the accelerator pedal depth D is equal to or less than the first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than the first preset resistance F1, the control module 101 controls the power generation P1 of the sub-motor 5.

According to one embodiment of the invention, the control module 101 is further configured to: when the engine 1 is controlled to independently drive the sub motor 5 to generate electricity and the power motor 2 is controlled to independently output driving force, the generated power of the engine 1 is obtained according to the following formula:

P0＝P1/η/ζ

wherein, P0 is the power generated by the engine 1, P1 is the power generated by the auxiliary motor 5, eta is the belt transmission efficiency, and zeta is the efficiency of the auxiliary motor 5.

That is, in the case where the engine 1 can generate only without being involved in driving, the control module 101 may calculate the power generation P0 of the engine 1 from the power generation power of the sub-motor 5, the belt transmission efficiency η, and the efficiency ζ of the sub-motor 5, and control the engine 1 to drive the sub-motor 5 to generate power with the obtained power generation P0, so as to control the power generation of the sub-motor 5.

Further, after the sub-motor 5 enters the generated power adjustment mode, the control module 101 may control the generated power of the sub-motor 5, and the generated power control process of the control module 101 according to the embodiment of the present invention will be described in detail below.

According to one embodiment of the invention, the control module 101 is further configured to: the generated power P1 of the sub motor 5 is controlled according to the whole vehicle required power P2 of the hybrid vehicle and the charging power P3 of the power battery 3.

According to one embodiment of the present invention, the formula for controlling the generated power P1 of the sub-motor 5 according to the whole vehicle required power P2 of the hybrid vehicle and the charging power P3 of the power battery is as follows:

P1=p2+p3, wherein p2=p11+p21,

It should be noted that the electrical device includes the first electrical device 10 and the second electrical device 30, that is, the electrical device power P21 may include power required by the high-voltage electrical device and the low-voltage electrical device. .

It should be further noted that the vehicle driving power P11 may include the output power control module 101 of the power motor 2 may obtain the vehicle driving power P11 according to a preset accelerator-torque curve of the power motor 2 and a rotation speed of the power motor 2, where the preset accelerator-torque curve may be determined when the power of the hybrid electric vehicle is matched. In addition, the control module 101 may obtain the electrical device power P21 in real time according to the electrical device operated by the whole vehicle, for example, calculate the electrical device power P21 through DC consumption on the bus. Further, the control module 101 may acquire the charging power P3 of the power battery 3 according to the SOC value of the power battery 3. Assuming that the real-time acquired vehicle driving power p11=b1kw, the electric device power p21=b2kw, the charging power p3=b3kw of the power battery 3, and the generated power of the sub-motor 5=b1+b2+b3.

Specifically, during the running of the hybrid vehicle, the control module 101 may obtain the charging power P3 of the power battery 3, the entire vehicle driving power P11, and the electrical equipment power P21, and take the sum of the charging power P3 of the power battery 3, the entire vehicle driving power P11, and the electrical equipment power P21 as the generated power P1 of the sub-motor 5, so that the control module 101 may control the generated power of the sub-motor 5 according to the calculated P1 value, for example, the control module 101 may control the output torque and the rotation speed of the engine 1 according to the calculated P1 value, so as to control the power of the engine 1 driving the sub-motor 5 to generate power.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: the SOC value change rate of the power battery 3 is obtained, and the generated power P1 of the sub-motor 5 is controlled according to the relationship between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economy region of the engine 1 and the SOC value change rate of the power battery.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after determining the minimum output power Pmin corresponding to the optimal economic region of the engine, the control module 101 may control the power generation of the sub-motor 5 according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1 and the SOC value change rate of the power battery 3.

As will be further described below, the control module 101 controls a specific adjustment manner of the generated power of the sub-motor 5 according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economy region of the engine 1 and the SOC value change rate of the power battery 3.

In one embodiment of the first case, when the vehicle required power P2 is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, the control module 101 obtains the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and determines whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the vehicle required power P2, wherein if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the vehicle required power P2, the engine 1 is controlled to generate electricity at the minimum output power Pmin to control the generated power P1 of the sub-motor 5; if the charging power P3 of the power battery 3 is greater than or equal to the difference between the minimum output power Pmin and the vehicle demand power P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the vehicle demand power P2, and the engine is controlled to generate electricity with the obtained output power so as to control the generated power P1 of the auxiliary motor 5.

It should be noted that, the first relation table between the SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3 may be pre-stored in the control module 101, so that after the control module 101 obtains the SOC value change rate of the power battery 3, the charging power P3 of the corresponding power battery 3 may be obtained by comparing the first relation table. The SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3 satisfy the relationship shown in table 1 above.

As known from table 1, when the SOC value change rate obtained by the control module 101 is A1, the obtained charging power P3 of the corresponding power battery 3 is B1; when the SOC value change rate obtained by the control module 101 is A2, the obtained charging power P3 of the corresponding power battery 3 is B2; when the control module 101 acquires when the rate of change of the SOC value is A3, the obtained charging power P3 of the corresponding power battery 3 is B3; when the SOC value change rate obtained by the control module 101 is A4, the obtained charging power P3 of the corresponding power battery 3 is B4; when the SOC value change rate obtained by the control module 101 is A5, the obtained charging power P3 of the corresponding power battery 3 is B5.

Specifically, when the sub motor 5 is controlled in generating power, the entire vehicle driving power P11 and the electrical equipment power P21 are obtained in real time to obtain the entire vehicle required power P2 of the hybrid vehicle, and the entire vehicle required power P2 of the hybrid vehicle is determined. When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, the charging power P3 of the power battery 3 can be obtained according to the SOC value change rate of the power battery 3, and whether the charging power P3 of the power battery 3 is smaller than or equal to the difference between the minimum output power Pmin and the required power P2 of the whole vehicle is determined.

When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine 1, if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, namely P3 is smaller than Pmin-P2, the engine 1 is controlled to generate electricity at the minimum output power Pmin so as to control the generated power of the auxiliary motor 1; if the charging power P3 of the power battery 3 is greater than or equal to the difference between the minimum output power Pmin and the whole vehicle required power P2, namely, P3 is greater than or equal to Pmin-P2, the output power of the engine 1 in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the whole vehicle required power P2, and the power generation is performed by controlling the engine 1 to obtain the output power so as to control the power generation power of the auxiliary motor 5.

In one embodiment of the second case, when the vehicle-mounted required power P2 is equal to or greater than the minimum output power Pmin corresponding to the optimal economy area of the engine and equal to or less than the maximum allowable power generation Pmax of the sub-motor 5, the control module 101 obtains the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, obtains the output power of the engine 1 in the preset optimal economy area according to the sum of the charging power P3 of the power battery 3 and the vehicle-mounted required power P2, and generates power by controlling the engine 1 to generate power to control the power generation power P1 of the sub-motor 5.

Specifically, when the vehicle demand power P2 is greater than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and less than the maximum allowable generated power Pmax of the sub-motor 5, the control module 101 further obtains the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3 when controlling the engine 1 to operate in the preset optimal economic area, and obtains the output power of the engine 1 in the preset optimal economic area according to the sum of the charging power P3 of the power battery 3 and the vehicle demand power P2, where the obtained output power=p3+p2. Further, the control module 101 controls the engine 1 to generate electricity at the obtained output power to control the generated power P1 of the sub-motor 5, thereby increasing the SOC value of the power battery 3 and operating the engine 1 in a preset optimal economy region.

Thus, when the vehicle-mounted power demand P2 is greater than the maximum allowable generated power Pmax of the sub-motor 5, the power battery 3 discharges the outside to supply power to the power motor 2, and at this time, the control module 101 controls the power motor 2 to output power to the wheels 7 of the hybrid vehicle so that the engine 1 operates in a preset optimal economic zone.

Embodiment four:

in some embodiments of the present invention, the control module 101 is configured to obtain an SOC value (State of Charge, also called residual Charge) of the power battery 3, an SOC value of the low-voltage battery 20, and a vehicle speed of the hybrid vehicle, and control the sub-motor 5 to enter a power generation adjustment mode according to the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle, so that the engine 1 operates in a preset optimal economic area, where, after the sub-motor 5 enters the power generation adjustment mode, the control module 101 is further configured to adjust the power generation of the sub-motor 5 according to the SOC value of the low-voltage battery 20. The power generation power adjustment mode is a mode for adjusting the power generation power of the engine, and in the power generation power adjustment mode, the engine 1 can be controlled to drive the auxiliary motor 5 to generate power so as to adjust the power generation power of the auxiliary motor 5.

When the engine 1 drives the auxiliary motor 5 to generate power, the control module 101 may first obtain the SOC value of the power battery 3 and the speed of the hybrid vehicle, and then control the auxiliary motor 5 to enter a power generation adjustment mode according to the SOC value of the power battery 3 and the speed of the hybrid vehicle, so that the engine 1 works in a preset optimal economic area. In the generated power adjustment mode, the control module 101 may adjust the generated power of the sub-motor 5 on the premise that the engine 1 is operated in a preset optimal economy area. After the sub-motor 5 enters the generated power adjustment mode, the control module 101 further adjusts the generated power of the sub-motor 5 according to the SOC value of the low-voltage battery 20.

Therefore, the engine 1 can work in the preset optimal economic area, and the fuel consumption of the engine 1 in the preset optimal economic area is the lowest, and the fuel economy is the highest, so that the fuel consumption of the engine 1 can be reduced, the noise of the engine 1 is reduced, and the running economy of the whole vehicle is improved. In addition, the auxiliary motor 5 has higher power generation power and power generation efficiency during low-speed running, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power motor and the high-voltage electrical equipment can be guaranteed to be powered by charging the power battery, so that the power motor can be guaranteed to drive the whole vehicle to run normally, the low-voltage electrical equipment can be guaranteed to be powered by charging the low-voltage storage battery, and the low-voltage power supply of the whole vehicle can be realized through the low-voltage storage battery when the auxiliary motor stops generating power and the power battery fails or is insufficient in electric quantity, so that the whole vehicle can be guaranteed to run in a pure fuel mode, and the running mileage of the whole vehicle is improved.

Further, according to an embodiment of the present invention, the control module 101 is configured to: when the SOC value of the power battery 3 is greater than a preset limit value and less than or equal to a first preset value, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the sub-motor 5 is controlled to enter the generated power adjustment mode.

The first preset value may be an upper limit value of the SOC value of the power battery 3, which is set in advance, for example, a determination value of stopping charging, and may be preferably 30%. The preset limit value may be a preset lower limit value of the SOC value of the power battery 3, for example, a determination value of stopping the discharge, and may be preferably 10%. According to the first preset value and the preset limit value, the SOC value of the power battery 3 can be divided into three sections, namely a first electric quantity section, a second electric quantity section and a third electric quantity section, when the SOC value of the power battery 3 is smaller than or equal to the preset limit value, the SOC value of the power battery 3 is in the first electric quantity section, and at the moment, the power battery 3 is charged and not discharged; when the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, the SOC value of the power battery 3 is in the second electric quantity interval, and the power battery 3 has a charging requirement at the moment, so that the power battery 3 can be actively charged; when the SOC value of the power battery 3 is greater than the first preset value, the SOC value of the power battery 3 is in the third electric power interval, and the power battery 3 may not be charged at this time, that is, the power battery 3 may not be actively charged.

Specifically, after the control module 101 obtains the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle, it may determine a section in which the SOC value of the power battery 3 is located, if the SOC value of the power battery 3 is in the second electric quantity section, the SOC value of the power battery 3 is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery 3 may be charged, at this time, the control module 101 further determines whether the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the auxiliary motor 5 is controlled to enter the generated power adjustment mode, at this time, the vehicle speed of the hybrid vehicle is lower, the required driving force is less, the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only drive the auxiliary motor 5 to generate power and not participate in driving.

Therefore, at low speed, the engine only generates electricity and does not participate in driving, as the engine does not participate in driving, the clutch is not needed, therefore, the abrasion or sliding abrasion of the clutch can be reduced, meanwhile, the feeling of setback is reduced, and the comfort is improved.

Further, the control module 101 is further configured to: when the SOC value of the power battery 3 is greater than a preset limit value and equal to or less than a first preset value, and the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the vehicle demand power of the hybrid vehicle is obtained, and when the vehicle demand power is equal to or less than the maximum allowable generated power of the sub motor 5, the sub motor 5 is controlled to enter a generated power adjustment mode.

That is, after determining that the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, and the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the control module 101 may further determine whether the vehicle demand power is greater than the maximum allowable power generation of the sub-motor 5, and if the vehicle demand power is less than or equal to the maximum allowable power generation of the sub-motor 5, control the sub-motor 5 to enter the power generation adjustment mode, at this time, the driving force required by the vehicle is less, and the vehicle demand power is less, the power motor 2 is sufficient to drive the hybrid vehicle to travel, and the engine 1 may only drive the sub-motor 5 to generate power without participating in driving.

Still further, the control module 101 is further configured to: when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the required power of the whole vehicle is smaller than or equal to the maximum allowable generated power of the auxiliary motor, the depth of an accelerator pedal of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are obtained, and when the depth of the accelerator pedal is smaller than or equal to the first preset depth and the whole vehicle resistance of the hybrid electric vehicle is smaller than or equal to the first preset resistance, the auxiliary motor is controlled to enter a generated power adjusting mode.

That is, after determining that the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, and the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, and the vehicle required power is less than or equal to the maximum allowable generated power of the sub-motor 5, the control module 101 may further determine whether the accelerator pedal depth is greater than the first preset depth and the vehicle resistance of the hybrid vehicle is greater than the first preset resistance, and if the accelerator pedal depth is less than or equal to the first preset depth or the vehicle resistance of the hybrid vehicle is less than or equal to the first preset resistance, the sub-motor 5 is controlled to enter the generated power adjustment mode, at this time, the driving force required by the vehicle is less, and the vehicle required power is less, and the accelerator pedal depth is also less, and the vehicle resistance is also less, and the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only drive the sub-motor 5 to generate power, and not participate in driving.

In addition, according to one embodiment of the invention, the control module 101 is further configured to: when the SOC value of the power battery 3 is smaller than a preset limit value, or the vehicle speed of the hybrid electric vehicle is greater than or equal to a first preset vehicle speed, or the required power of the whole vehicle is greater than the maximum allowable power generation power of the auxiliary motor 5, or the depth of the accelerator pedal is greater than a first preset depth, or the whole vehicle resistance of the hybrid electric vehicle is greater than a first preset resistance, the engine 1 is controlled to participate in driving.

And, the control module 101 is further configured to: when the SOC value of the power battery 3 is equal to or less than a preset limit value, the engine 1 is controlled to participate in driving so that the engine 1 outputs power to wheels through the clutch 6; when the SOC value of the power battery 3 is equal to or less than a first preset value, the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, and the accelerator pedal depth is greater than the first preset depth, the engine 1 is controlled to participate in driving so that the engine 1 outputs power to wheels through the clutch 6; when the SOC value of the power battery 3 is equal to or less than a first preset value, the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, and the vehicle resistance of the hybrid vehicle is greater than the first preset resistance, the engine 1 participates in driving so that the engine 1 outputs power to wheels through the clutch 6.

That is, the control module 101 may obtain the SOC value of the power battery 3, the accelerator pedal depth, the vehicle speed, the vehicle resistance and the vehicle-mounted power demand of the hybrid vehicle in real time, and determine the SOC value of the power battery 3, the accelerator pedal depth, the vehicle speed and the vehicle resistance of the hybrid vehicle:

firstly, when the SOC value of the power battery 3 is smaller than the preset limit value, the power battery 3 cannot provide enough electric energy due to the too low electric quantity of the power battery 3, the control module 101 controls the engine 1 and the power motor 2 to participate in driving at the same time, at this time, the control module 101 may further control the engine 1 to drive the auxiliary motor 5 to generate electricity, and the engine 1 may work in the preset optimal economic area by adjusting the generated power of the auxiliary motor 5.

Secondly, when the SOC value of the power battery 3 is less than or equal to a first preset value, the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed, and the depth of the accelerator pedal is greater than the first preset depth, the control module 101 controls the engine 1 and the power motor 2 to participate in driving simultaneously because the depth of the accelerator pedal is deeper, at this time, the control module 101 can also control the engine 1 to drive the auxiliary motor 5 to generate electricity, and the engine 1 can work in a preset optimal economic area by adjusting the generated power of the auxiliary motor 5.

Thirdly, when the SOC value of the power battery 3 is smaller than or equal to a first preset value, the vehicle speed of the hybrid electric vehicle is smaller than the first preset vehicle speed, and the vehicle resistance of the hybrid electric vehicle is larger than the first preset resistance, the control module 101 controls the engine 1 and the power motor 2 to participate in driving simultaneously due to the larger vehicle resistance, at this time, the control module 101 can also control the engine 1 to drive the auxiliary motor 5 to generate electricity, and the engine 1 can work in a preset optimal economic area by adjusting the generated electricity of the auxiliary motor 5.

According to one embodiment of the invention, the control module 101 is further configured to: after the sub motor 5 enters the generated power adjustment mode, the generated power of the sub motor 5 is adjusted according to the whole vehicle required power of the hybrid vehicle, the charging power of the power battery 3, the charging power of the low-voltage storage battery 20, and the SOC value of the low-voltage storage battery 20.

Specifically, the formula for adjusting the generated power of the sub motor 5 according to the whole vehicle required power of the hybrid vehicle, the charged power of the power battery 3, and the charged power of the low-voltage storage battery 20 may be as follows:

p1=p2+p3+p4, wherein p2=p11+p21,

wherein, P1 is the power generated by the auxiliary motor 5, P2 is the power required by the whole vehicle, P3 is the charging power of the power battery 3, P4 is the charging power of the low-voltage battery 20, P11 is the driving power of the whole vehicle, and P21 is the power of the electrical equipment.

It should be further noted that the whole vehicle driving power P11 may include an output power of the power motor 2, and the control module 101 may obtain the whole vehicle driving power P11 according to a preset accelerator-torque curve of the power motor 2 and a rotation speed of the power motor 2, where the preset accelerator-torque curve may be determined when the power of the hybrid electric vehicle is matched; the control module 101 may obtain the electrical equipment power P21 in real time according to the electrical equipment running on the whole vehicle, for example, calculate the electrical equipment power P21 through DC consumption on the bus; the control module 101 may obtain the charging power P3 of the power battery 3 according to the SOC value of the power battery 3, and obtain the charging power P4 of the low-voltage battery 20 according to the SOC value of the low-voltage battery 20.

Specifically, during the running of the hybrid vehicle, the control module 101 may obtain the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20, the entire vehicle driving power P11, and the electrical equipment power P21, and take the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20, the entire vehicle driving power P11, and the electrical equipment power P21 as the power generation power P1 of the sub-motor 5, so that the control module 101 may adjust the power generation power of the sub-motor 5 according to the calculated P1 value, for example, the control module 101 may control the output torque and the rotational speed of the engine 1 according to the calculated P1 value, so as to adjust the power generated by the sub-motor 5 driven by the engine 1.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: and acquiring the change rate of the SOC value of the power battery 3, and adjusting the power generation power of the auxiliary motor 5 according to the relation between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1, and the change rate of the SOC value of the power battery 3, the SOC value of the low-voltage storage battery 20 and the change rate of the SOC value of the low-voltage storage battery 20.

It should be understood that the control module 101 may obtain the SOC value change rate of the power battery 3 according to the SOC value of the power battery 3, for example, collect the SOC value of the power battery 3 once every time interval t, so that the ratio of the difference between the current SOC value of the power battery 3 and the previous SOC value to the time interval t may be used as the SOC value change rate of the power battery 3. Similarly, the SOC value change rate of the low-voltage battery 20 may be obtained from the SOC value of the low-voltage battery 20, for example, the SOC value of the low-voltage battery 20 may be collected once every time interval t, so that the ratio of the difference between the current SOC value of the low-voltage battery 20 and the previous SOC value to the time interval t may be taken as the SOC value change rate of the low-voltage battery 20.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after determining the minimum output power Pmin corresponding to the optimal economic region of the engine, the control module 101 may adjust the power generation of the sub-motor 5 according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1, and the SOC value change rate of the power battery 3, the SOC value of the low-voltage battery 20, and the SOC value change rate of the low-voltage battery 20.

The specific adjustment manner of the power generation of the sub-motor 5 by the control module 101 according to the relationship between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine 1, and the SOC value change rate of the power battery 3, the SOC value of the low-voltage battery 20, and the SOC value change rate of the low-voltage battery 20 after the sub-motor 5 enters the power generation adjustment mode will be further described.

Specifically, the control module 101 is further configured to: when the SOC value of the low-voltage battery 20 is greater than a preset low-power threshold value, acquiring charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and judging whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, wherein if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, the power generation of the auxiliary motor 5 is regulated by controlling the engine 1 to generate power at the minimum output power; if the charging power P3 of the power battery 3 is equal to or greater than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the vehicle demand power P2, and the power generation is performed by controlling the engine 1 to obtain the output power so as to adjust the power generation power of the auxiliary motor 5.

Specifically, the control module 101 is further configured to: when the SOC value of the low-voltage battery 20 is smaller than or equal to a preset low-power threshold value, acquiring the SOC value change rate of the low-voltage battery 20 and the SOC value change rate of the power battery 3, acquiring the charging power P4 of the low-voltage battery 20 according to the SOC value change rate of the low-voltage battery 20 and the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and judging whether the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, wherein if the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 20 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, generating power of the auxiliary motor 5 is regulated by controlling the engine 1 to generate power at the minimum output power Pmin; if the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is equal to or greater than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle-mounted demand power P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage battery 20 and the vehicle-mounted demand power P2, and the power generation is performed by controlling the engine 1 to generate power with the obtained output power so as to adjust the power generation of the sub-motor 5.

It should be noted that, the first relation table between the SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3 may be pre-stored in the control module 101, so that after the control module 101 obtains the SOC value change rate of the power battery 3, the charging power P3 of the corresponding power battery 3 may be obtained by comparing the first relation table. For example, a first table of the relationship between the SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3 may be as shown in table 1 above.

As can be seen from table 1, when the SOC value change rate of the power battery 3 is A1, the control module 101 can obtain the charging power P3 of the corresponding power battery 3 as B1; when the SOC value change rate of the power battery 3 is A2, the control module 101 may obtain the charging power P3 of the corresponding power battery 3 as B2; when the SOC value change rate of the power battery 3 is A3, the control module 101 may obtain the charging power P3 of the corresponding power battery 3 as B3; when the SOC value change rate of the power battery 3 is A4, the control module 101 may obtain the charging power P3 of the corresponding power battery 3 as B4; the control block 101 may acquire the charging power P3 of the corresponding power battery 3 as B5 when the SOC value change rate of the power battery 3 is A5.

Similarly, a second relation table between the SOC value change rate of the low-voltage battery 20 and the charging power P4 of the low-voltage battery 20 may be pre-stored in the control module 101, and thus, after obtaining the SOC value change rate of the low-voltage battery 20, the control module 101 may obtain the charging power P4 of the corresponding low-voltage battery 20 by comparing the second relation table. For example, a first table of the relationship between the SOC value change rate of the low-voltage battery 20 and the charging power P4 of the low-voltage battery 20 may be as shown in table 2 below.

TABLE 2

Rate of change of SOC value of low-voltage battery 20	A11	A12	A13	A14	A15
						Charging power of low-voltage battery 20	B11	B12	B13	B14	B15

As can be seen from table 2, when the SOC value change rate of the low-voltage battery 20 is a11, the control module 101 can obtain the charging power P4 of the corresponding low-voltage battery 20 as B11; when the SOC value change rate of the low-voltage battery 20 is a12, the control module 101 may obtain the charging power P4 of the corresponding low-voltage battery 20 as B12; when the SOC value change rate of the low-voltage battery 20 is a13, the control module 101 may obtain the charging power P4 of the corresponding low-voltage battery 20 as B13; when the SOC value change rate of the low-voltage battery 20 is a14, the control module 101 may obtain the charging power P4 of the corresponding low-voltage battery 20 as B14; when the SOC value change rate of the low-voltage battery 20 is a15, the control module 101 may acquire the charging power P4 of the corresponding low-voltage battery 20 as B15.

Specifically, after the sub-motor 5 enters the generated power adjustment mode, the control module 101 may acquire the SOC value of the low-voltage battery 20, the SOC value of the power battery 3, and the vehicle-required power P2 (the sum of the vehicle-driving power P11 and the electrical device power P21), and then determine whether the SOC value of the low-voltage battery 20 is greater than a preset low-battery threshold.

If the SOC value of the low-voltage battery 20 is greater than a preset low-power threshold value, acquiring the SOC value change rate of the power battery 3, inquiring the charging power P3 of the power battery 3 corresponding to the SOC value change rate of the power battery 3, selecting a proper charging power P3 to enable the SOC value of the power battery 3 to rise, further judging whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the whole vehicle required power P2, and if yes, namely, if P3 is smaller than Pmin-P2, generating power by controlling the engine 1 by the minimum output power Pmin to regulate the generating power of the auxiliary motor 5, namely, controlling the engine 1 to operate at the minimum output power Pmin corresponding to the optimal economic area; if not, namely, P3 is more than or equal to Pmin-P2, obtaining the output power of the engine 1 in a preset optimal economic area according to the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle, and generating electricity by controlling the engine 1 to obtain the output power so as to adjust the generated power of the auxiliary motor 5, that is, the corresponding output power is found in the preset optimal economic area of the engine 1, and the obtained output power may be the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle, that is, (p2+p3 or p11+p21+p3), and at this time, the engine 1 may be controlled to generate power with the obtained output power.

If the SOC value of the low-voltage battery 20 is less than or equal to the preset low-power threshold value, the SOC value change rate of the power battery 3 is obtained, the charging power P3 of the power battery 3 corresponding to the SOC value change rate of the power battery 3 is queried, so that an appropriate charging power P3 is selected to enable the SOC value of the power battery 3 to rise, the SOC value change rate of the low-voltage battery 20 is obtained, the charging power P4 of the low-voltage battery 20 corresponding to the SOC value change rate of the low-voltage battery 20 is queried, so that the SOC value of the low-voltage battery 20 can rise by selecting the appropriate charging power P4, and further, whether the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle required power P2 is determined. If the power is positive, namely P3+P4 is less than Pmin-P2, the engine 1 is controlled to generate electricity at the minimum output power Pmin so as to regulate the power generation power of the auxiliary motor 5, namely the engine 1 is controlled to operate at the minimum output power Pmin corresponding to the optimal economic area, and the power of the power battery 3 and the low-voltage storage battery 20 is charged by subtracting the power of the whole vehicle required power P2 from the minimum output power Pmin corresponding to the optimal economic area, namely Pmin-P2; if not, namely P3+P4 is more than or equal to Pmin-P2, obtaining the output power of the engine 1 in a preset optimal economic area according to the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the whole vehicle required power P2, and generating electricity by controlling the engine 1 to obtain the output power so as to adjust the generated power of the auxiliary motor 5, namely searching corresponding power in the preset optimal economic area of the engine 1, wherein the obtained output power is the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the whole vehicle required power P2, namely (P2+P3+P4 or P11+P21+P3+P4), and controlling the engine 1 to generate electricity by the obtained output power.

In summary, according to the power system of the hybrid electric vehicle provided by the embodiment of the invention, the engine outputs power to the wheels of the hybrid electric vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid electric vehicle, the power battery supplies power to the power motor, the auxiliary motor generates power under the drive of the engine so as to realize at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter, the control module obtains the SOC value of the power battery, the SOC value of the low-voltage storage battery and the vehicle speed of the hybrid electric vehicle, and controls the auxiliary motor to enter a power generation power regulation mode according to the SOC value of the power battery and the vehicle speed of the hybrid electric vehicle so that the engine can operate in a preset optimal economic region, and after the auxiliary motor enters the power generation power regulation mode, the control module is also used for regulating the power generation power of the auxiliary motor according to the SOC value of the low-voltage storage battery, so that the engine is not involved in driving at low speed, the clutch is not used, the wear or sliding feeling of the clutch is reduced, the comfort is improved at the same time, the engine can work in an economic region at low speed, the power generation is not driven, the noise is reduced, the whole vehicle is reduced, the power consumption is only is reduced, and the low power speed performance is kept smooth, and the vehicle performance is low.

Fifth embodiment:

in some embodiments of the present invention, the control module 101 is configured to obtain an SOC value (State of Charge, also called residual Charge) of the power battery 3, an SOC value of the low-voltage battery 20, and a vehicle speed of the hybrid vehicle, control the power generated by the sub-motor 5 according to the SOC value of the power battery 3, the SOC value of the low-voltage battery 20, and the vehicle speed of the hybrid vehicle, and obtain the power generated by the engine 1 according to the power generated by the sub-motor 5 to control the engine 1 to operate in a preset optimal economic area.

It should also be noted that, the preset optimal economy area of the engine 1 may be determined in conjunction with the engine universal map. An example of an engine universal characteristic map is shown in fig. 7, in which the ordinate on the side is the output torque of the engine 1, the abscissa is the rotation speed of the engine 1, and the curve a is the fuel economy curve of the engine 1. The region corresponding to the fuel economy curve is the optimal economy region of the engine, that is, when the torque and the torque of the engine 1 are on the optimal fuel economy curve of the engine, the engine is in the optimal economy region. Thus, in an embodiment of the present invention, the control module 101 may operate the engine 1 in a preset optimal economy region by controlling the rotational speed and output torque of the engine 1 to fall on an engine fuel economy curve, such as curve a.

When the engine 1 drives the auxiliary motor 5 to generate electricity, the control module 101 may first obtain the SOC value of the power battery 3, the SOC value of the low-voltage battery 20 and the speed of the hybrid vehicle, then control the power generated by the auxiliary motor 5 according to the SOC value of the power battery 3, the SOC value of the low-voltage battery 20 and the speed of the hybrid vehicle, and further obtain the power generated by the engine 1 according to the power generated by the auxiliary motor 5, so as to control the engine 1 to operate in a preset optimal economic area. In other words, the control module 101 may control the generated power of the sub-motor 5 on the premise that the engine 1 is operated in a preset optimal economy area.

Further, according to an embodiment of the present invention, the control module 101 is configured to: when the SOC value of the power battery 3 is greater than a preset limit value and equal to or less than a first preset value, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the generated power of the sub motor 5 is controlled.

The first preset value may be an upper limit value of the SOC value of the power battery 3, which is set in advance, for example, a determination value of stopping charging, and may be preferably 30%. The preset limit value may be a preset lower limit value of the SOC value of the power battery 3, for example, a determination value of stopping the discharge, and may be preferably 10%. According to the first preset value and the preset limit value, the SOC value of the power battery 3 can be divided into three sections, namely a first electric quantity section, a second electric quantity section and a third electric quantity section, when the SOC value of the power battery 3 is smaller than or equal to the preset limit value, the SOC value of the power battery 3 is in the first electric quantity section, and at the moment, the power battery 3 is charged and not discharged; when the SOC value of the power battery 3 is larger than a preset limit value and smaller than or equal to a first preset value, the SOC value of the power battery 3 is in a second electric quantity interval, and at the moment, the power battery 3 has a charging requirement, so that the power battery 3 can be actively charged; when the SOC value of the power battery 3 is greater than the first preset value, the SOC value of the power battery 3 is in the third electric power interval, and the power battery 3 may not be charged at this time, that is, the power battery 3 may not be actively charged. Specifically, after the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle are obtained, the control module 101 may determine a section in which the SOC value of the power battery 3 is located, if the SOC value of the power battery 3 is located in the medium power section, the SOC value of the power battery 3 is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery 3 may be charged, at this time, the control module 101 further determines whether the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the power generated by the sub-motor 5 is controlled, at this time, the vehicle speed of the hybrid vehicle is lower, the required driving force is less, the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only drive the sub-motor 5 to generate power and not participate in driving.

Further, the control module 101 is further configured to: when the SOC value of the power battery 3 is greater than a preset limit value and equal to or less than a first preset value, and the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the vehicle demand power of the hybrid vehicle is obtained, and when the vehicle demand power is equal to or less than the maximum allowable power generation power of the sub motor 5, the power generation power of the sub motor 5 is controlled.

That is, after determining that the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, and the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the control module 101 may further determine whether the vehicle demand power is greater than the maximum allowable power generation of the sub-motor 5, and if the vehicle demand power is less than or equal to the maximum allowable power generation of the sub-motor 5, control the power generation of the sub-motor 5, at this time, the driving force required by the vehicle is less, and the vehicle demand power is less, the power motor 2 is sufficient to drive the hybrid vehicle to run, and the engine 1 may drive only the sub-motor 5 to generate power without participating in driving.

Still further, the control module 101 is further configured to: when the SOC value of the power battery 3 is greater than a preset limit value and less than or equal to a first preset value, the vehicle speed of the hybrid electric vehicle is less than a first preset vehicle speed, and the required power of the whole vehicle is less than or equal to the maximum allowable generated power of the auxiliary electric machine 5, the accelerator pedal depth of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are obtained, and when the accelerator pedal depth is less than or equal to the first preset depth and the whole vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the generated power of the auxiliary electric machine 5 is controlled.

That is, after determining that the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, and the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, and the vehicle required power is less than or equal to the maximum allowable generated power of the sub motor 5, the control module 101 may further determine whether the accelerator pedal depth is greater than the first preset depth or whether the vehicle resistance of the hybrid vehicle is greater than the first preset resistance, and if the accelerator pedal depth is less than or equal to the first preset depth and the vehicle resistance of the hybrid vehicle is less than or equal to the first preset resistance, the generated power of the sub motor 5 is controlled, at this time, the driving force required by the vehicle is less, and the vehicle required power is less, and the accelerator pedal depth is also less, and the vehicle resistance is also less, and the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only drive the sub motor 5 to generate power, without participating in driving.

According to a specific embodiment of the present invention, the control module 101 is further configured to: when the engine 1 is controlled to independently drive the sub motor 5 to generate electricity and the power motor 2 is controlled to independently output driving force, the generated power of the engine 1 is obtained according to the following formula:

P0＝P1/η/ζ

More specifically, the control module 101 is further configured to: when the vehicle-mounted required power is greater than the maximum allowable generated power of the sub-motor 5, the engine 1 is also controlled to participate in driving so that the engine 1 outputs power to wheels through a clutch.

firstly, when the SOC value of the power battery 3 is smaller than the preset limit value, the power battery 3 cannot provide enough electric energy due to the too low electric quantity of the power battery 3, the control module 101 controls the engine 1 and the power motor 2 to participate in driving at the same time, at this time, the control module 101 may further control the engine 1 to drive the auxiliary motor 5 to generate electricity, and the engine 1 may work in the preset optimal economic area by controlling the generated power of the engine 1.

Secondly, when the SOC value of the power battery 3 is less than or equal to a first preset value, the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed, and the depth of the accelerator pedal is greater than the first preset depth, the control module 101 controls the engine 1 and the power motor 2 to participate in driving simultaneously because the depth of the accelerator pedal is deeper, at this time, the control module 101 can also control the engine 1 to drive the auxiliary motor 5 to generate power, and the engine 1 can work in a preset optimal economic area by controlling the power generation of the engine 1.

Thirdly, when the SOC value of the power battery 3 is smaller than or equal to a first preset value, the vehicle speed of the hybrid electric vehicle is smaller than the first preset vehicle speed, and the vehicle resistance of the hybrid electric vehicle is larger than the first preset resistance, the control module 101 controls the engine 1 and the power motor 2 to participate in driving simultaneously due to the larger vehicle resistance, at this time, the control module 101 can also control the engine 1 to drive the auxiliary motor 5 to generate electricity, and the engine 1 can work in a preset optimal economic area by controlling the generated electricity of the engine 1.

Further, when the engine 1 drives only the sub-motor 5 to generate power and does not participate in driving, the control module 101 may control the generated power of the sub-motor 5, and the generated power control process of the control module 101 according to the embodiment of the present invention will be described in detail below.

According to one embodiment of the invention, the control module 101 is further configured to: the generated power of the sub motor 5 is controlled according to the whole vehicle required power of the hybrid vehicle, the charged power of the power battery 3, and the charged power of the low-voltage storage battery 20.

Specifically, the formula for controlling the generated power of the sub motor 5 according to the whole vehicle required power of the hybrid vehicle, the charged power of the power battery 3, and the charged power of the low-voltage storage battery 20 is as follows:

p1=p2+p3+p4, wherein p2=p11+p21,

Specifically, during the running of the hybrid vehicle, the control module 101 may obtain the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20, the entire vehicle driving power P11, and the electrical equipment power P21, and take the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20, the entire vehicle driving power P11, and the electrical equipment power P21 as the power generation power P1 of the sub-motor 5, so the control module 101 may control the power generation power of the sub-motor 5 according to the calculated P1 value, for example, the control module 101 may control the output torque and the rotation speed of the engine 1 according to the calculated P1 value, so as to control the power generated by the sub-motor 5 driven by the engine 1.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: the change rate of the SOC value of the power battery 3 is obtained, and the power generation power of the auxiliary motor 5 is controlled according to the relation between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic area of the engine 1, and the change rate of the SOC value of the power battery 3, the SOC value of the low-voltage storage battery 20 and the change rate of the SOC value of the low-voltage storage battery 20.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after determining the minimum output power Pmin corresponding to the optimal economic region of the engine, the control module 101 may control the power generation of the sub-motor 5 according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1, and the SOC value change rate of the power battery 3, the SOC value of the low-voltage battery 20, and the SOC value change rate of the low-voltage battery 20.

The following further describes a specific control manner in which, when the engine 1 drives only the sub-motor 5 to generate power and does not participate in driving, the control module 101 adjusts the generated power of the sub-motor 5 according to the relationship between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine 1, and the SOC value change rate of the power battery 3, the SOC value of the low-voltage battery 20, and the SOC value change rate of the low-voltage battery 20.

Specifically, the control module 101 is further configured to: when the SOC value of the low-voltage battery 20 is greater than a preset low-power threshold value, acquiring the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and judging whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, wherein if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, the power generation of the auxiliary motor 5 is controlled by controlling the engine 1 to generate power at the minimum output power; if the charging power of the power battery 3 is equal to or greater than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the vehicle demand power P2, and the power generation is performed by controlling the engine 1 to obtain the output power so as to control the power generation of the auxiliary motor 5.

Specifically, the control module 101 is further configured to: when the SOC value of the low-voltage battery 20 is smaller than or equal to a preset low-power threshold value, acquiring the SOC value change rate of the low-voltage battery 20 and the SOC value change rate of the power battery 3, acquiring the charging power P4 of the low-voltage battery 20 according to the SOC value change rate of the low-voltage battery 20 and the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and judging whether the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, wherein if the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle demand power P2, generating power of the auxiliary motor 5 is controlled by controlling the engine 1 to generate power at the minimum output power Pmin; if the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is equal to or greater than the difference between the minimum output power Pmin corresponding to the optimal economy region of the engine 1 and the vehicle-mounted demand power P2, the output power of the engine 1 in the preset optimal economy region is obtained according to the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage battery 20 and the vehicle-mounted demand power P2, and the power generation is performed by controlling the engine 1 to generate power with the obtained output power to control the power generation of the sub-motor 5.

Similarly, a second relation table between the SOC value change rate of the low-voltage battery 20 and the charging power P4 of the low-voltage battery 20 may be pre-stored in the control module 101, and thus, after obtaining the SOC value change rate of the low-voltage battery 20, the control module 101 may obtain the charging power P4 of the corresponding low-voltage battery 20 by comparing the second relation table. For example, a first table of the relationship between the SOC value change rate of the low-voltage battery 20 and the charging power P4 of the low-voltage battery 20 may be as shown in table 2 above.

Specifically, when controlling the generated power of the sub-motor 5, the control module 101 may obtain the SOC value of the low-voltage battery 20, the SOC value of the power battery 3, and the vehicle-required power P2 (the sum of the vehicle-driving power P11 and the electrical device power P21), and then determine whether the SOC value of the low-voltage battery 20 is greater than a preset low-battery threshold.

If the SOC value of the low-voltage battery 20 is greater than a preset low-power threshold value, acquiring the SOC value change rate of the power battery 3, inquiring the charging power P3 of the power battery 3 corresponding to the SOC value change rate of the power battery 3, selecting a proper charging power P3 to enable the SOC value of the power battery 3 to rise, further judging whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the whole vehicle required power P2, and if yes, that is, if P3 is smaller than Pmin-P2, controlling the engine 1 to generate power at the minimum output power Pmin so as to control the power generated by the auxiliary motor 5, that is, controlling the engine 1 to operate at the minimum output power Pmin corresponding to the optimal economic area; if the power of the engine 1 is not less than P3, that is, P3 is greater than or equal to Pmin-P2, the output power of the engine 1 in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle, and the power of the auxiliary motor 5 is controlled by controlling the engine 1 to generate power by the obtained output power, that is, searching the corresponding output power in the preset optimal economic area of the engine 1, wherein the obtained output power can be the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle, that is, (P2+P3 or P11+P21+P3), and the obtained output power of the engine 1 can be controlled to generate power at the moment.

If the SOC value of the low-voltage battery 20 is less than or equal to the preset low-power threshold value, the SOC value change rate of the power battery 3 is obtained, the charging power P3 of the power battery 3 corresponding to the SOC value change rate of the power battery 3 is queried, so that an appropriate charging power P3 is selected to enable the SOC value of the power battery 3 to rise, the SOC value change rate of the low-voltage battery 20 is obtained, the charging power P4 of the low-voltage battery 20 corresponding to the SOC value change rate of the low-voltage battery 20 is queried, so that the SOC value of the low-voltage battery 20 can rise by selecting the appropriate charging power P4, and further, whether the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the vehicle required power P2 is determined. If the power is positive, namely P3+P4 is less than Pmin-P2, the engine 1 is controlled to generate electricity at the minimum output power Pmin so as to control the generated power of the auxiliary motor 5, namely the engine 1 is controlled to operate at the minimum output power Pmin corresponding to the optimal economic area, and the power of the whole vehicle required power P2 is subtracted from the minimum output power Pmin corresponding to the optimal economic area, namely Pmin-P2, so as to charge the power battery 3 and the low-voltage storage battery 20; if the power of the engine 1 in the preset optimal economic area is not greater than P3+P4 is greater than or equal to Pmin-P2, the power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the whole vehicle required power P2, the power of the auxiliary motor 5 is controlled by controlling the engine 1 to generate power with the obtained output power, namely, the corresponding power is searched in the preset optimal economic area of the engine 1, and the obtained output power can be the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the whole vehicle required power P2, namely (P2+P3+P4 or P11+P21+P3+P4), and the engine 1 is controlled to generate power with the obtained output power.

In summary, according to the power system of the hybrid electric vehicle provided by the embodiment of the invention, the engine outputs power to the wheels of the hybrid electric vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid electric vehicle, the power battery supplies power to the power motor, the auxiliary motor generates power under the drive of the engine so as to realize at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter, the control module obtains the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle, controls the power generation of the auxiliary motor according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle, and obtains the power generation of the engine according to the power generation of the auxiliary motor so as to control the engine to operate in a preset optimal economic area, thereby enabling the engine not to participate in driving at low speed, further avoiding the use of the clutch, reducing wear or sliding friction of the clutch, simultaneously reducing the sense of the pause, improving the comfort, enabling the engine to work in the economic area only to generate power and not drive, reducing the noise of the engine, reducing the oil consumption, maintaining the balance of the low speed and the electric power and the smoothness of the whole vehicle.

In addition, in the case of the optical fiber, the embodiment of the invention also provides a rectifying and voltage stabilizing circuit for motor power generation in the power system of the hybrid electric vehicle. The following describes a rectifying and voltage stabilizing circuit for motor power generation in a power system of a hybrid electric vehicle according to an embodiment of the present invention with reference to the accompanying drawings.

Fig. 8 is a block diagram showing a configuration of a power system of a hybrid vehicle according to an embodiment of the present invention. As shown in fig. 8, the power system of the hybrid vehicle includes: an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4, a sub-motor 5, and a voltage stabilizing circuit 300.

As shown in fig. 8 to 10, the engine 1 outputs power to wheels 7 of the hybrid vehicle through a clutch 6; the power motor 2 is used for outputting driving force to the wheels 7 of the hybrid vehicle. That is, the power system of the embodiment of the present invention may supply power to the normal running of the hybrid vehicle through the engine 1 and/or the power motor 2, in other words, in some embodiments of the present invention, the power source of the power system may be the engine 1 and the power motor 2, either of the engine 1 and the power motor 2 may output power to the wheels 7 alone, or the engine 1 and the power motor 2 may output power to the wheels 7 simultaneously.

The power battery 3 is used for supplying power to the power motor 2; the sub-motor 5 is connected to the engine 1, and for example, the sub-motor 5 may be connected to the engine 1 through a train end of the engine 1, and the sub-motor 5 may be connected to the power motor 2, the DC-DC converter 4, and the power battery 3, respectively. The voltage stabilizing circuit 300 is connected between the auxiliary motor 5 and the DC-DC converter 4, and the voltage stabilizing circuit 300 performs voltage stabilizing treatment on the direct current output to the DC-DC converter 4 when the auxiliary motor 5 generates electricity, so that the stabilized voltage supplies power to the whole vehicle piezoelectric device through the DC-DC converter 4. In other words, the electric energy output when the sub-motor 5 generates electric power passes through the voltage stabilizing circuit 300, and then the stabilized voltage is output to the DC-DC converter 4.

Therefore, the power motor 2 and the auxiliary motor 5 can respectively and correspondingly serve as a driving motor and a generator, so that the auxiliary motor 5 can have higher power generation power and power generation efficiency at a low speed, thereby meeting the power consumption requirement of low-speed running, maintaining the low-speed electric balance of the whole vehicle, maintaining the low-speed smoothness and improving the performance of the whole vehicle. And the voltage stabilizing circuit 300 can be used for stabilizing the direct current output to the DC-DC converter 4 when the auxiliary motor 5 generates electricity, so that the input voltage of the DC-DC converter 4 is kept stable, and the normal operation of the DC-DC converter is ensured.

Further, when the sub-motor 5 generates power under the drive of the engine 1, at least one of charging the power battery 3, supplying power to the power motor 2, and supplying power to the DC-DC converter 4 can be realized. In other words, the engine 1 can drive the sub-motor 5 to generate electricity, the electric power generated by the sub-motor 5 may be supplied to at least one of the power battery 3, the power motor 2, and the DC-DC converter 4. It should be understood that the engine 1 may drive the sub-motor 5 to generate electricity while outputting power to the wheels 7, or may drive the sub-motor 5 to generate electricity alone.

Wherein the sub motor 5 may be a BSG motor. The sub-motor 5 is a high-voltage motor, for example, the generated voltage of the sub-motor 5 is equal to the voltage of the power battery 3, so that the power generated by the sub-motor 5 can directly charge the power battery 3 without voltage conversion, and can also supply power to the power motor 2 and/or the DC-DC converter 4. The auxiliary motor 5 can also belong to a high-efficiency generator, for example, the auxiliary motor 5 is driven to generate electricity at the idle speed of the engine 1, so that the electricity generation efficiency of more than 97% can be realized.

It should be noted that, the voltage stabilizing circuit 300 may be disposed on an output line of the sub-motor 5, where the sub-motor 5 is connected to the power motor 2, the power battery 3 and the DC-DC converter 4 through the voltage stabilizing circuit 300, as shown in fig. 9b and 9c, at this time, when the sub-motor 5 generates electricity, a stable voltage may be output through the voltage stabilizing circuit 300, so as to implement voltage stabilizing charging for the power battery 3, voltage stabilizing power supplying for the power motor 2 and voltage stabilizing power supplying for the DC-DC converter 4, thereby ensuring normal operation of the DC-DC converter 4 no matter whether the power battery 3 is connected with the DC-DC converter 4 or not. The voltage stabilizing circuit 300 may also be disposed on the inlet line of the DC-DC converter 4, and the sub-motor 5 may be connected to the DC-DC converter 4 and the power battery 3, respectively, while the power battery 3 may be connected to the DC-DC converter 4, as shown in fig. 8 and 9a, so that when the power battery 3 is disconnected from the DC-DC converter 4, the voltage output to the DC-DC converter 4 when the sub-motor 5 generates electricity is still stable, thereby ensuring that the DC-DC converter 4 operates normally.

Further, the sub-motor 5 may be used to start the engine 1, i.e., the sub-motor 5 may perform a function of starting the engine 1, for example, when starting the engine 1, the sub-motor 5 may rotate a crankshaft of the engine 1 to bring a piston of the engine 1 to an ignition position, thereby performing a start of the engine 1, whereby the sub-motor 5 may perform a function of a starter in the related art.

As described above, the engine 1 and the power motor 2 can both be used to drive the wheels 7 of a hybrid vehicle. For example, as shown in fig. 9a, 9b, the engine 1 and the power motor 2 drive together the same wheel of the hybrid vehicle such as a pair of front wheels 71 (including a left front wheel and a right front wheel); as another example, as shown in fig. 9c, the engine 1 may drive a first wheel of the hybrid vehicle, such as a pair of front wheels 71 (including a left front wheel and a right front wheel), and the power motor 2 may drive a second wheel of the hybrid vehicle, such as a pair of rear wheels 72 (including a left rear wheel and a right rear wheel).

In other words, when the engine 1 and the power motor 2 jointly drive the pair of front wheels 71, the driving force of the power system is output to the pair of front wheels 71, and the whole vehicle adopts a two-drive driving mode; when the engine 1 drives the pair of front wheels 71 and the power motor 2 drives the pair of rear wheels 72, the driving force of the power system is output to the pair of front wheels 71 and the pair of rear wheels 72, respectively, and the whole vehicle adopts a four-wheel drive mode.

Further, in the two-drive driving mode, as shown in fig. 9a and 9b, the power system of the hybrid vehicle further includes a final drive 9 and a transmission 90, wherein the engine 1 outputs power to a first wheel of the hybrid vehicle, such as a pair of front wheels 71, through the clutch 6, the transmission 90 and the final drive 9, and the power motor 2 outputs driving force to the first wheel of the hybrid vehicle, such as a pair of front wheels 71, through the final drive 9. Wherein the clutch 6 and the transmission 90 may be integrally provided.

In the four-wheel drive mode, as shown in fig. 9c in combination, the power system of the hybrid vehicle further includes a first transmission 91 and a second transmission 92, wherein the engine 1 outputs power to a first wheel of the hybrid vehicle, such as a pair of front wheels 71, through the clutch 6 and the first transmission 91, and the power motor 2 outputs driving force to a second wheel of the hybrid vehicle, such as a pair of rear wheels 72, through the second transmission 92.

Wherein the clutch 6 and the first transmission 91 may be integrally provided.

In the embodiment of the present invention, since the generated voltage of the sub-motor 5 is generally connected to both ends of the power battery 3, the voltage input to the DC-DC converter 4 is stable when the power battery 3 is connected to the DC-DC converter 4. When the power battery 3 fails or is damaged and is disconnected from the DC-DC converter 4, the ac power output when the sub-motor 5 generates power needs to be controlled at this time, that is, the DC power output to the DC-DC converter 4 when the sub-motor 5 generates power is subjected to voltage stabilizing treatment by the voltage stabilizing circuit 300.

In some embodiments of the present invention, as shown in fig. 10, the sub-motor 5 includes a sub-motor controller 51, the sub-motor controller 51 includes an inverter 511 and a regulator 512, and the regulator 512 is configured to output a first regulation signal for regulating d-axis current of the sub-motor 5 and a second regulation signal for regulating q-axis current of the sub-motor 5 according to an output signal of the voltage stabilizing circuit 300 when the power battery 3 is disconnected from the DC-DC converter 4, so as to stabilize a DC bus voltage output from the inverter 511.

Further, in some embodiments, as shown in fig. 10, the voltage stabilizing circuit 300 includes a first voltage sampler 61 and a target voltage collector 62. The first voltage sampler 61 samples the dc bus voltage output from the inverter 511 to obtain a first voltage sampling value and outputs the first voltage sampling value to the regulator 512, and the target voltage collector 62 acquires a target reference voltage and transmits the target reference voltage to the regulator 512. The regulator 512 is configured to output a first regulation signal and a second regulation signal according to a voltage difference between a target reference voltage and a first voltage sampling value. The output signal of the voltage stabilizing circuit 300 includes a first voltage sampling value and a target reference voltage.

Specifically, the sub motor controller 51 is connected to the DC-DC converter 4 through the voltage stabilizing circuit 300. The sub motor controller 51 outputs a dc bus voltage through the inverter 511, and the first voltage sampler 61 samples the dc bus voltage output from the inverter 511 to obtain a first voltage sampling value and outputs the first voltage sampling value to the regulator 512. The target voltage collector 62 acquires a target reference voltage and sends the target reference voltage to the regulator 512, the regulator 512 outputs a first regulating signal and a second regulating signal according to a voltage difference between the target reference voltage and the first voltage sampling value, the d-axis current of the sub motor 5 is regulated by the first regulating signal, the q-axis current of the sub motor 5 is regulated by the second regulating signal, so that the sub motor controller 51 controls the inverter 511 according to the d-axis current and the q-axis current of the sub motor 5 when the power battery 3 is disconnected from the DC-DC converter 4, and the DC bus voltage output by the inverter 511 is kept stable.

In some examples, the inverter 511 may be controlled using PWM (Pulse Width Modulation, pulse width modulation technique) to stabilize the dc bus voltage output by the inverter 511. As shown in fig. 11, the regulator 512 includes an error calculation unit a, a first PID adjustment unit b, and a second PID adjustment unit c.

The error calculating unit a is connected to the first voltage sampler 61 and the target voltage collector 62, respectively, and is configured to obtain a voltage difference between the target reference voltage and the first voltage sampling value. The first PID adjusting unit b is connected with the error calculating unit a, and adjusts the voltage difference between the target reference voltage and the first voltage sampling value to output a first adjusting signal. The second PID adjusting unit c is connected with the error calculating unit a, and adjusts the voltage difference between the target reference voltage and the first voltage sampling value to output a second adjusting signal.

Specifically, as shown in fig. 11, the first voltage sampler 61 samples the dc bus voltage output from the inverter 511 in real time to obtain a first voltage sampling value, and outputs the first voltage sampling value to the error calculator a, and the target voltage collector 62 acquires a target reference voltage, and outputs the target reference voltage to the error calculation unit a. The error calculation unit a obtains the voltage difference between the target reference voltage and the first voltage sampling value, and inputs the voltage difference to the first PID adjustment unit b and the second PID adjustment unit c, respectively, and outputs a first adjustment signal (i.e. Id in FIG. 11) through the first PID adjustment unit b ^* ) And outputting a second regulation signal (i.e., iq in fig. 11) through a second PID regulation unit c ^* ). At this time, the three-phase current outputted from the sub motor 5 is converted into a d-axis current Id and a q-axis current Iq in the dq coordinate system by 3S/2R conversion, and Id is obtained respectively ^* And Id, iq ^* And Iq, and respectively controlling the difference through a corresponding PID regulator to obtain the alpha-axis voltage U alpha of the auxiliary motor 5 and the beta-axis voltage U beta of the auxiliary motor 5; the U α and U β are input to the SVPWM module, a three-phase duty ratio is output, the inverter 511 is controlled by the duty ratio, the d-axis current Id and the q-axis current Iq output from the sub motor 5 are adjusted by the inverter 511, the adjusted d-axis current of the sub motor is adjusted again by the first control signal, and the q-axis current of the sub motor is adjusted again by the second adjustment signal. Thus, closed-loop control of the d-axis current and the q-axis current of the sub-motor is formed, and the DC bus voltage output from the inverter 511, that is, the DC voltage output to the DC-DC converter 4 at the time of power generation of the sub-motor 5 can be kept stable by the closed-loop control.

In the sub motor controller 51, the dc voltage output from the inverter 511 and the back electromotive force output from the sub motor 5 have a certain correlation, and in order to ensure the control efficiency, the voltage output from the inverter 511 may be set to 3/2 of the phase voltage (i.e., the maximum phase voltage in the driving state is 2/3 of the dc bus voltage). Accordingly, the dc voltage output from the inverter 511 has a constant relationship with the rotation speed of the sub motor 5, and when the rotation speed of the sub motor 5 is higher, the dc voltage output from the inverter 511 is higher, and when the rotation speed of the sub motor 5 is lower, the dc voltage output from the inverter 511 is lower.

Further, in order to ensure that the direct current voltage input to the DC-DC converter 4 is within the preset voltage range, in some embodiments of the present invention, as shown in fig. 10, the voltage stabilizing circuit 300 may further include a voltage stabilizer 63, a second voltage sampler 64, and a voltage stabilizing controller 65.

The voltage regulator 63 is connected to the DC output terminal of the inverter 511, the voltage regulator 63 performs voltage stabilization processing on the DC bus voltage output by the inverter 511, and the output terminal of the voltage regulator 63 is connected to the input terminal of the DC-DC converter 4. The second voltage sampler 64 samples the output voltage of the voltage regulator 63 to obtain a second voltage sample value. The voltage stabilizing controller 65 is connected to the voltage stabilizer 63 and the second voltage sampler 64, and the voltage stabilizing controller 65 is configured to control the output voltage of the voltage stabilizer 63 according to the preset reference voltage and the second voltage sampling value so that the output voltage of the voltage stabilizer 63 is in the preset voltage interval.

In some examples, the voltage regulator 63 may employ a switching type voltage regulator circuit, such as a BOOST circuit, which is capable of not only boosting voltage but also high in control accuracy. The switching device in the BOOST circuit can adopt silicon carbide MOSFET, such as IMW120R45M1 of Infraise, can withstand voltage of 1200V, has internal resistance of 45mΩ, and has the characteristics of high withstand voltage, small internal resistance and good heat conduction performance, and the loss is tens of times smaller than that of a high-speed IGBT with the same specification. The driving chip of the voltage stabilizer 63 can adopt 1EDI60N12AF of Infrax, which adopts non-magnetic core voltage transformation isolation, and is safe and reliable to control. It will be appreciated that the number of components, the driving chip can generate a driving signal.

In other examples, voltage regulator 63 may employ a BUCK-BOOST type BUCK-BOOST circuit that is capable of BUCK at high speeds, BOOST at low speeds, and control with high accuracy.

In still other examples, regulator 63 may also employ a linear regulator circuit or a three terminal regulator circuit (e.g., LM317 and 7805, etc.).

It will be appreciated that the circuit configuration of the first voltage sampler 61 and the second voltage sampler 64 may be identical for ease of circuit design. For example, the first voltage sampler 61 and the second voltage sampler 64 may each include a differential voltage circuit, which has the characteristics of high accuracy and convenience in adjusting the amplification factor.

Alternatively, the voltage stabilizing controller 65 may use a PWM dedicated modulation chip SG3525, which has the characteristics of small size, simple control, and capability of outputting a stable PWM wave.

For example, the working procedure of the power system of the hybrid electric vehicle is as follows: the second voltage sampler 64 samples the output voltage of the voltage stabilizer 63 to obtain a second voltage sampling value, and outputs the second voltage sampling value to the chip SG3525, the chip SG3525 may set a reference voltage, compare the reference voltage with the second voltage sampling value, and generate two paths of PWM waves by combining the triangular wave generated by the chip SG3525, and control the voltage stabilizer 63 through the two paths of PWM waves so that the voltage output by the voltage stabilizer 63 to the DC-DC converter 4 is in a preset voltage interval, such as 11-13V, thereby ensuring the normal operation of the low voltage load in the hybrid electric vehicle.

If the output dc bus voltage is too low and the second voltage sampling value is small, SG3525 may emit PWM wave with relatively large duty ratio to boost.

Therefore, the auxiliary motor 5 and the DC-DC converter 4 are provided with a single voltage-stabilizing power supply channel, when the power battery 3 breaks down and is disconnected with the DC-DC converter 4, the single voltage-stabilizing power supply channel of the auxiliary motor 5 and the DC-DC converter 4 can ensure low-voltage power consumption of the whole vehicle, ensure that the whole vehicle can realize pure fuel mode running, and improve the running mileage of the whole vehicle.

In one embodiment of the present invention, as shown in fig. 12, when the power battery 3 is damaged and the connection with the DC-DC converter 4 is disconnected, the voltage stabilizing circuit 300 is connected to the inlet terminal of the DC-DC converter 4.

Wherein the power motor 2 further comprises a second controller 21, and the sub-motor controller 51 is connected to the second controller 21 and to the DC-DC converter 4 via a voltage stabilizing circuit 300. The inverter 511 may convert the alternating current generated by the sub motor 5 into high voltage direct current, for example, 600V high voltage direct current, to supply at least one of the power motor 2 and the DC-DC converter 4.

It will be appreciated that the second controller 21 may have a DC-AC conversion unit that may convert the high voltage direct current output from the inverter 511 into alternating current to charge the power motor 4.

Specifically, as shown in fig. 12, the inverter 511 of the sub motor controller 51 has a first DC terminal DC1, the second controller 21 has a second DC terminal DC2, and the DC-DC converter 4 has a third DC terminal DC3. The first DC terminal DC1 of the sub motor controller 51 is connected to the third DC terminal DC3 of the DC-DC converter 4 through the voltage stabilizing circuit 300 to provide a stabilized voltage to the DC-DC converter 4, and the DC-DC converter 4 may perform DC-DC conversion on the stabilized direct current. Also, the inverter 511 of the sub-motor controller 51 may output high voltage direct current to the second controller 21 through the first direct current terminal DC1 to supply power to the power motor 2.

Further, as shown in fig. 12, the DC-DC converter 4 is also connected to the electric device 10 and the low-voltage battery 20 in the hybrid vehicle, respectively, to supply power to the electric device 10 and the low-voltage battery 20, and the low-voltage battery 20 is also connected to the electric device 10.

Specifically, as shown in fig. 12, the DC-DC converter 4 further has a fourth direct current terminal DC4, and the DC-DC converter 4 may convert the high-voltage direct current output from the sub-motor 5 through the sub-motor controller 51 into a low-voltage direct current and output the low-voltage direct current through the fourth direct current terminal DC 4. The fourth direct current terminal DC4 of the DC-DC converter 4 is connected to the electrical device 10 to supply power to the electrical device 10, wherein the electrical device 10 may be a low voltage electrical device including, but not limited to, a car light, a radio, etc. The fourth direct current terminal DC4 of the DC-DC converter 4 may also be connected to the low voltage battery 20 for charging the low voltage battery 20. The low-voltage storage battery 20 is connected with the electrical equipment 10 to supply power to the electrical equipment 10, particularly, when the auxiliary motor 5 stops generating power, the low-voltage storage battery 20 can supply power to the electrical equipment 10, so that the low-voltage power consumption of the whole vehicle is ensured, the whole vehicle can realize the pure fuel mode driving, and the driving mileage of the whole vehicle is improved.

It should be noted that, in the embodiment of the present invention, the low voltage may refer to a voltage of 12V (volts) or 24V, the high voltage may refer to a voltage of 600V, and the preset voltage interval may refer to 11 to 13V or 23 to 25V, but is not limited thereto.

In summary, the power system of the hybrid electric vehicle disclosed by the embodiment of the invention not only can maintain the low-speed electric balance and the low-speed smoothness of the whole vehicle, but also can ensure the normal operation of the DC-DC converter when the power battery is in failure or damage to disconnect the DC-DC converter, and has high control precision and small loss.

In addition, the embodiment of the invention also provides a hybrid electric vehicle.

Fig. 13 is a block schematic diagram of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 13, the hybrid vehicle 200 includes the power system 100 of the hybrid vehicle of the above-described embodiment.

According to the hybrid electric vehicle proposed in the embodiment of the present invention, can maintain the low-speed electric balance and the low-speed smoothness of the whole vehicle.

Based on the hybrid electric vehicle and the power system thereof in the embodiment, the embodiment of the invention also provides a power generation control method of the hybrid electric vehicle.

Fig. 14 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 14, the power generation control method of the hybrid vehicle includes the steps of:

S1: and acquiring the SOC value of a power battery and the SOC value of a low-voltage storage battery of the hybrid electric vehicle.

The SOC value of the power battery and the SOC value of the low-voltage storage battery may be acquired by a battery management system of the hybrid electric vehicle to obtain the SOC value of the power battery and the SOC value of the low-voltage storage battery.

S2: and obtaining the maximum allowable generated power of the auxiliary motor of the hybrid electric vehicle.

According to a specific example of the present invention, the maximum allowable generated power of the sub-motor is correlated with the performance parameters of the sub-motor and the engine, etc., in other words, the maximum allowable generated power of the sub-motor may be preset in advance in accordance with the performance parameters of the sub-motor and the engine, etc.

S3: and judging whether the auxiliary motor charges the power battery and/or the low-voltage storage battery according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the maximum allowable generated power of the auxiliary motor.

Therefore, the power battery is charged to ensure the electricity consumption requirements of the power motor and the high-voltage electrical equipment, further ensure that the whole vehicle is driven by the power motor to normally run, and ensure the electricity consumption requirements of the low-voltage electrical equipment by charging the low-voltage storage battery, and when the auxiliary motor stops generating electricity and the power battery fails or has insufficient electric quantity, the low-voltage power supply of the whole vehicle is realized through the low-voltage storage battery, so that the whole vehicle can realize pure fuel mode driving, and the driving mileage of the whole vehicle is improved.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is smaller than the first preset SOC value and the SOC value of the low-voltage battery is greater than or equal to the second preset SOC value, the engine of the hybrid electric vehicle is controlled to drive the sub-motor to generate electricity so as to charge the power battery.

It should be understood that the first preset SOC value may be a charging limit value of the power battery, the second preset SOC value may be a charging limit value of the low-voltage battery, and the first preset SOC value and the second preset SOC value may be set independently in sequence according to the performance of each battery.

Specifically, after the SOC value of the power battery and the SOC value of the low-voltage storage battery are obtained, whether the SOC value of the power battery is smaller than a first preset SOC value or not and whether the SOC value of the low-voltage storage battery is smaller than a second preset SOC value or not can be judged, if the SOC value of the power battery is smaller than the first preset SOC value and the SOC value of the low-voltage storage battery is larger than or equal to the second preset SOC value, it is indicated that the remaining capacity of the power battery is low and needs to be charged, and the remaining capacity of the low-voltage storage battery is high and does not need to be charged, and at the moment, the control module controls the engine to drive the auxiliary motor to generate electricity to charge the power battery.

As described above, the sub-motor belongs to a high-voltage motor, for example, the generated voltage of the sub-motor is equivalent to the voltage of the power battery, so that the power generated by the sub-motor can directly charge the power battery without voltage conversion.

Similarly, when the SOC value of the power battery is larger than or equal to a first preset SOC value and the SOC value of the low-voltage storage battery is smaller than a second preset SOC value, the engine of the hybrid electric vehicle is controlled to drive the auxiliary motor to generate electricity so as to charge the low-voltage storage battery through the DC-DC converter of the hybrid electric vehicle.

That is, if the SOC value of the power battery is greater than or equal to the first preset SOC value and the SOC value of the low-voltage battery is smaller than the second preset SOC value, it is indicated that the remaining capacity of the power battery is high, charging is not needed, the remaining capacity of the low-voltage battery is low, charging is needed, and at this time, the control module controls the engine to drive the auxiliary motor to generate electricity so as to charge the low-voltage battery through the DC-DC converter.

As described above, the sub-motor is a high-voltage motor, for example, the generated voltage of the sub-motor is equal to the voltage of the power battery, so that the electric energy generated by the sub-motor needs to be converted in voltage by the DC-DC converter and then charged into the low-voltage battery.

Still further, according to an embodiment of the present invention, when the SOC value of the power battery is smaller than the first preset SOC value and the SOC value of the low-voltage battery is smaller than the second preset SOC value, the charging power of the power battery is obtained according to the SOC value of the power battery, the charging power of the low-voltage battery is obtained according to the SOC value of the low-voltage battery, and when the sum of the charging power of the power battery and the charging power of the low-voltage battery is larger than the maximum allowable power of the sub-motor, the engine of the hybrid electric vehicle is controlled to drive the sub-motor to generate power so as to charge the low-voltage battery through the DC-DC converter of the hybrid electric vehicle.

And when the sum of the charging power of the power battery and the charging power of the low-voltage storage battery is smaller than or equal to the maximum allowable generating power of the auxiliary motor, the engine is controlled to drive the auxiliary motor to generate electricity so as to charge the power battery, and the low-voltage storage battery is charged through the DC-DC converter.

That is, if the SOC value of the power battery is smaller than the first preset SOC value and the SOC value of the low-voltage battery is smaller than the second preset SOC value, it is indicated that the remaining electric power of the power battery and the low-voltage battery are both low and need to be charged, and at this time, it is further determined whether the sum of the charging power of the power battery and the charging power of the low-voltage battery is larger than the maximum allowable power of the sub-motor.

If the sum of the charging power of the power battery and the charging power of the low-voltage storage battery is larger than the maximum allowable generating power of the auxiliary motor, the fact that the electric energy generated by the auxiliary motor is insufficient for simultaneously charging the two batteries is indicated, and the low-voltage storage battery is charged preferentially at the moment, namely the engine is controlled to drive the auxiliary motor to generate electricity so as to charge the low-voltage storage battery through the DC-DC converter.

If the sum of the charging power of the power battery and the charging power of the low-voltage storage battery is smaller than or equal to the maximum allowable generating power of the auxiliary motor, the electric energy generated by the auxiliary motor can charge the two batteries simultaneously, and the power battery and the low-voltage storage battery are charged simultaneously at the moment, namely the engine is controlled to drive the auxiliary motor to generate electricity so as to charge the power battery, and the low-voltage storage battery is charged through the DC-DC converter.

Of course, it should be understood that when the SOC value of the power battery is equal to or greater than the first preset SOC value and the SOC value of the low-voltage battery is equal to or greater than the second preset SOC value, it is indicated that the remaining electric power of the power battery and the low-voltage battery are both high, and charging is not required, and the power battery and the low-voltage battery may not be charged at this time.

Specifically, as shown in fig. 15, the power generation control method of the hybrid vehicle according to the embodiment of the invention specifically includes the following steps:

s101: and acquiring the SOC value of the power battery and the SOC value of the low-voltage storage battery.

S102: and judging whether the SOC value of the power battery is smaller than a first preset SOC value.

If yes, step S105 is performed; if not, step S103 is performed.

S103: and judging whether the SOC value of the low-voltage storage battery is smaller than a second preset SOC value.

If yes, go to step S104; if not, return to step S101.

S104: and charging the low-voltage storage battery, namely controlling the engine to drive the auxiliary motor to generate power so as to charge the low-voltage storage battery through the DC-DC converter.

S105: judging SOC value of low-voltage storage battery whether the value is smaller than a second preset SOC value.

If yes, step S107 is performed; if not, step S106 is performed.

S106: and charging the power battery, namely controlling the engine to drive the auxiliary motor to generate electricity so as to charge the power battery.

S107: and acquiring the charging power of the power battery and the charging power of the low-voltage storage battery.

S108: and judging whether the sum of the charging power of the power battery and the charging power of the low-voltage storage battery is larger than the maximum allowable power generation power of the auxiliary motor.

If yes, step S109 is executed; if not, step S110 is performed.

S109: the low-voltage storage battery is charged preferentially, namely the engine is controlled to drive the auxiliary motor to generate electricity so as to charge the low-voltage storage battery through the DC-DC converter.

S110: meanwhile, the power battery and the low-voltage storage battery are charged, namely, the engine is controlled to drive the auxiliary motor to generate electricity so as to charge the power battery, and meanwhile, the low-voltage storage battery is charged through the DC-DC converter.

In summary, according to the power generation control method of the hybrid electric vehicle provided by the embodiment of the invention, whether the sub-motor charges the power battery and/or the low-voltage storage battery is judged according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the maximum allowable power generation power of the motor, so that the method can charge the power battery and the low-voltage storage battery, therefore, the power motor and the high-voltage electrical equipment can be ensured to have the power consumption requirements, the power motor can be further ensured to drive the whole vehicle to normally run, the power consumption requirements of the low-voltage electrical equipment can be ensured, and the whole vehicle can be ensured to run in a pure fuel mode when the auxiliary motor stops generating power and the power battery fails or has insufficient electric quantity, so that the running mileage of the whole vehicle is improved.

Based on the hybrid electric vehicle and the power system thereof in the above embodiment, the embodiment of the invention also provides another power generation control method of the hybrid electric vehicle.

Fig. 16 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 16, the power generation control method of the hybrid vehicle includes the steps of:

s10: and acquiring the SOC value of the power battery and the speed of the hybrid electric vehicle.

The SOC value of the power battery may be acquired by a battery management system of the hybrid vehicle so that the SOC value of the power battery is acquired.

S20: and controlling the auxiliary motor to enter a generated power adjusting mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable the engine to run in a preset optimal economic area.

It should also be noted that the predetermined optimal economy area of the engine may be determined in conjunction with the engine universal map. An example of an engine universal characteristic curve is shown in fig. 7, in which the ordinate on the side is the output torque of the engine, the abscissa is the rotational speed of the engine, and curve a is the fuel economy curve of the engine. The region corresponding to the fuel economy curve is the optimal economy region of the engine, namely, when the torque and the torque of the engine are positioned on the optimal fuel economy curve of the engine, the engine is positioned in the optimal economy region. Thus, in an embodiment of the present invention, the engine may be operated in a preset optimal economy region by controlling the rotational speed and output torque of the engine to fall on an engine fuel economy curve, such as curve a.

Further, according to an embodiment of the present invention, during the running of the hybrid vehicle, the SOC value of the power battery and the vehicle speed V of the hybrid vehicle are obtained, and the sub-motor is controlled to enter the generated power adjustment mode according to the SOC value of the power battery and the vehicle speed V of the hybrid vehicle, so that the engine is operated in a preset optimal economic zone. The power generation power adjustment mode is a mode for adjusting the power generation power of the engine, and in the power generation power adjustment mode, the engine 1 can be controlled to drive the auxiliary motor 5 to generate power so as to adjust the power generation power of the auxiliary motor 5.

Specifically, during the running process of the hybrid electric vehicle, the engine can output power to wheels of the hybrid electric vehicle through the clutch, and the engine can also drive the auxiliary motor to generate power. Therefore, the output power of the engine mainly comprises two parts, wherein one part is output to the auxiliary motor, namely, the power for driving the auxiliary motor to generate electricity, and the other part is output to the wheels, namely, the power for driving the wheels.

When the engine drives the auxiliary motor to generate power, the SOC value of the power battery and the speed of the hybrid electric vehicle can be obtained first, and then the auxiliary motor is controlled to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle, so that the engine works in a preset optimal economic area. In the generated power adjustment mode, the generated power of the sub motor can be adjusted on the premise that the engine is operated in a preset optimal economic area.

Therefore, the engine can work in the preset optimal economic area, and the oil consumption of the engine in the preset optimal economic area is the lowest, and the fuel economy is the highest, so that the oil consumption of the engine can be reduced, the noise of the engine is reduced, and the running economy of the whole vehicle is improved. In addition, the auxiliary motor has higher power generation power and power generation efficiency during low-speed running, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power battery is charged, so that the power motor and the high-voltage electrical equipment can be ensured to be required to be powered, and the power motor is further ensured to drive the whole vehicle to normally run.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value, the sub-motor is controlled to enter the generated power adjustment mode if the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed.

The first preset value may be an upper limit value of the SOC value of the power battery, which is set in advance, for example, a determination value of stopping charging, and may be preferably 30%. The preset limit value may be a preset lower limit value of the SOC value of the power battery, for example, a determination value of stopping the discharge, and may be preferably 10%. According to the first preset value and the preset limit value, the SOC value of the power battery can be divided into three sections, namely a first electric quantity section, a second electric quantity section and a third electric quantity section, when the SOC value of the power battery is smaller than or equal to the preset limit value, the SOC value of the power battery is in the first electric quantity section, and the power battery is only charged and not discharged at the moment; when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value, the SOC value of the power battery is in a second electric quantity interval, and at the moment, the power battery has a charging requirement, so that the power battery can be actively charged; when the SOC value of the power battery is larger than the first preset value, the SOC value of the power battery is in the third electric quantity interval, and the power battery can be not charged at the moment, namely the power battery can not be actively charged.

Specifically, after the SOC value of the power battery and the vehicle speed V of the hybrid vehicle are obtained, a section in which the SOC value of the power battery is located may be determined, if the SOC value of the power battery is located in the medium electric quantity section, the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery may be charged, and at this time, it is further determined whether the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, and if the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, the sub-motor is controlled to enter the generated power adjustment mode, and at this time, the vehicle speed of the hybrid vehicle is lower, the required driving force is less, the power motor is sufficient to drive the hybrid vehicle, and the engine may only drive the sub-motor to generate power, and does not participate in driving.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than the preset limit value M2 and equal to or less than the first preset value M1, and the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, the vehicle required power P2 of the hybrid vehicle is also obtained, and when the vehicle required power P2 is equal to or less than the maximum allowable power Pmax of the sub-motor, the sub-motor is controlled to enter the power generation adjustment mode.

Specifically, during the running process of the hybrid electric vehicle, if the SOC value of the power battery is greater than a preset limit value M2 and less than or equal to a first preset value M1, and the vehicle speed V of the hybrid electric vehicle is less than a first preset vehicle speed V1, that is, the vehicle speed of the hybrid electric vehicle is low, the vehicle-mounted required power P2 of the hybrid electric vehicle is obtained, and when the vehicle-mounted required power P2 is less than or equal to the maximum allowable power generation Pmax of the sub-motor, the sub-motor is controlled to enter a power generation power adjustment mode.

Still further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value M1, the vehicle speed V of the hybrid vehicle is less than a first preset vehicle speed V1, and the vehicle required power P2 of the hybrid vehicle is equal to or less than the maximum allowable power generation Pmax of the sub-motor, the accelerator pedal depth D of the hybrid vehicle and the vehicle resistance F of the hybrid vehicle are also obtained, and when the accelerator pedal depth D is equal to or less than a first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than a first preset resistance F1, the sub-motor is controlled to enter the power generation adjustment mode.

Specifically, if the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value M1, the vehicle speed V of the hybrid electric vehicle is less than a first preset vehicle speed V1, and the vehicle required power P2 of the hybrid electric vehicle is equal to or less than the maximum allowable generated power Pmax of the auxiliary motor, the accelerator pedal depth D of the hybrid electric vehicle and the vehicle resistance F of the hybrid electric vehicle are obtained in real time, and when the accelerator pedal depth D is equal to or less than the first preset depth D1 and the vehicle resistance F of the hybrid electric vehicle is equal to or less than the first preset resistance F1, the hybrid electric vehicle is illustrated to operate in a low speed mode, and the auxiliary motor is controlled to enter a generated power adjustment mode.

Accordingly, when the SOC value of the power battery of the hybrid vehicle, the vehicle speed V, the accelerator pedal depth D, and the vehicle resistance F do not satisfy the above conditions, the engine may participate in driving, and the specific operation thereof is as follows.

According to one embodiment of the invention, when the SOC value of the power battery is smaller than a preset limit value, or the vehicle speed of the hybrid electric vehicle is greater than or equal to a first preset vehicle speed, or the required power of the whole vehicle is greater than the maximum allowable power generation power of the auxiliary motor, or the depth of the accelerator pedal is greater than a first preset depth, or the whole vehicle resistance of the hybrid electric vehicle is greater than a first preset resistance, the engine is controlled to participate in driving.

That is, when the SOC value of the power battery is smaller than the preset limit value M2, or the vehicle speed of the hybrid vehicle is greater than or equal to the first preset vehicle speed, or the required power of the whole vehicle is greater than the maximum allowable generated power of the sub-motor, or the depth of the accelerator pedal is greater than the first preset depth, or the resistance of the whole vehicle of the hybrid vehicle is greater than the first preset resistance, the engine is controlled to participate in driving, at this time, the power battery is no longer discharged, the required driving force of the whole vehicle is greater, the required power of the whole vehicle is greater, the depth of the accelerator pedal is greater, or the resistance of the whole vehicle is also greater, the power motor is insufficient to drive the hybrid vehicle to run, and the engine participates in driving to perform complementary driving.

Therefore, the engine can participate in driving when the driving force output by the power motor is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved.

More specifically, when the vehicle-mounted required power is greater than the maximum allowable generated power of the sub-electric motor, the engine is also controlled to participate in driving so that the engine outputs power to the wheels through the clutch.

And when the SOC value of the power battery is equal to or less than a preset limit value M2, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch; when the SOC value of the power battery is smaller than or equal to a first preset value M1, the speed V of the hybrid electric vehicle is smaller than the first preset speed V1, and the depth D of the accelerator pedal is larger than a first preset depth D1, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch; when the SOC value of the power battery is smaller than or equal to a first preset value M1, the speed V of the hybrid electric vehicle is smaller than the first preset speed V1, and the whole resistance F of the hybrid electric vehicle is larger than the first preset resistance F1, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch.

Specifically, when the engine drives the auxiliary motor to generate power and the power motor outputs driving force to wheels of the hybrid electric vehicle, the SOC value of the power battery, the depth D of an accelerator pedal of the hybrid electric vehicle, the vehicle speed V and the whole vehicle resistance F are obtained in real time, the SOC value of the power battery, the depth D of the accelerator pedal of the hybrid electric vehicle, the vehicle speed V and the whole vehicle resistance F are judged, and the power generation of the auxiliary motor is regulated according to the following three judgment results:

firstly, when the SOC value of the power battery is smaller than a preset limit value M2, the engine is controlled to output power to wheels through the clutch, so that the engine and the power motor participate in driving at the same time, the load of the power motor is reduced, the power consumption of the power battery is reduced, the engine can be ensured to work in a preset optimal economic area, and meanwhile, the rapid decline of the SOC value of the power battery is avoided.

Secondly, when the SOC value of the power battery is smaller than or equal to a first preset value M1, the speed V of the hybrid electric vehicle is smaller than the first preset speed V1, and the depth D of the accelerator pedal is larger than the first preset depth D1, the engine is controlled to output power to wheels through the clutch, so that the engine and the power motor participate in driving at the same time, the load of the power motor is reduced, the power consumption of the power battery is reduced, the engine can be ensured to work in a preset optimal economic area, and meanwhile, the rapid reduction of the SOC value of the power battery is avoided.

Thirdly, when the SOC value of the power battery is smaller than or equal to a first preset value M1, the speed V of the hybrid electric vehicle is smaller than the first preset speed V1, and the resistance F of the hybrid electric vehicle is larger than the first preset resistance F1, the engine is controlled to output power to wheels through the clutch, so that the engine and the power motor participate in driving at the same time, the load of the power motor is reduced, the power consumption of the power battery is reduced, the engine can be ensured to work in a preset optimal economic area, and meanwhile, the rapid reduction of the SOC value of the power battery is avoided.

Therefore, the engine can participate in driving when the driving force output by the power motor is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved. And moreover, the engine can be controlled to work in an economic area, and the fuel consumption of the engine in a preset optimal economic area is the lowest, so that the fuel consumption can be reduced, the noise of the engine is reduced, and the economic performance of the whole vehicle is improved.

Further, when the SOC value of the power battery is equal to or less than a preset limit value and the vehicle speed of the hybrid vehicle is greater than a first preset vehicle speed, the engine is controlled to participate in driving so that the engine outputs power to wheels through a clutch.

Of course, it should be understood that when the SOC value of the power battery is greater than the first preset value, the engine does not drive the auxiliary motor to generate power, and at this time, the electric quantity of the power battery is close to full power, no charging is needed, and the engine does not drive the auxiliary motor to generate power. That is, when the power of the power battery is close to full power, the engine does not drive the auxiliary motor to generate power, so that the auxiliary motor does not charge the power battery.

Further, after the sub-motor enters the generated power adjustment mode, the generated power of the sub-motor may be adjusted, and the generated power adjustment process according to the embodiment of the present invention will be described in detail below.

According to one embodiment of the invention, after the auxiliary motor enters the generated power adjustment mode, the generated power P1 of the auxiliary motor is adjusted according to the whole vehicle required power P2 of the hybrid electric vehicle and the charging power P3 of the power battery.

According to one embodiment of the present invention, the formula for adjusting the power generation P1 of the sub-motor according to the whole vehicle required power P2 of the hybrid vehicle and the charging power P3 of the power battery is as follows:

P1=p2+p3, wherein p2=p11+p21,

p1 is the power generated by the auxiliary motor, P2 is the power required by the whole vehicle, P3 is the charging power of the power battery, P11 is the power driven by the whole vehicle, and P21 is the power of the electrical equipment.

It should be noted that the electrical device includes a first electrical device and a second electrical device, that is, the electrical device power P21 may include power required by the high-voltage electrical device and the low-voltage electrical device.

It should be further noted that the whole vehicle driving power P11 may include an output power of the power motor 2, the whole vehicle driving power P11 may include an output power of the power motor, and the whole vehicle driving power P11 may be obtained according to a preset accelerator-torque curve of the power motor and a rotation speed of the power motor, where the preset accelerator-torque curve may be determined when the power of the hybrid electric vehicle is matched. In addition, the electrical equipment power P21 can be obtained in real time according to the electrical equipment running on the whole car, for example, the electrical equipment power P21 is calculated through the DC consumption on the bus. Further, the charging power P3 of the power battery may be obtained from the SOC value of the power battery. Assuming that the vehicle driving power p11=b1 kw, the electric device power p21=b2 kw, and the charging power p3=b3 kw of the power battery, the generated power of the sub-motor=b1+b2+b3.

Specifically, during the running process of the hybrid electric vehicle, the charging power P3 of the power battery, the driving power P11 of the whole vehicle and the power P21 of the electrical equipment can be obtained, and the sum of the charging power P3 of the power battery, the driving power P11 of the whole vehicle and the power P21 of the electrical equipment is taken as the power generation power P1 of the auxiliary motor, so that the power generation power of the auxiliary motor can be adjusted according to the calculated P1 value, for example, the output torque and the rotating speed of the engine can be controlled according to the calculated P1 value, so that the power generated by the auxiliary motor driven by the engine can be adjusted.

Further, according to an embodiment of the present invention, the adjustment of the generated power of the sub motor includes: and acquiring the SOC value change rate of the power battery, and adjusting the power generation power of the auxiliary motor according to the relation between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic area of the engine and the SOC value change rate of the power battery.

It should be understood that the SOC value change rate of the power battery may be obtained according to the SOC value of the power battery, for example, the SOC value of the power battery is collected once every time interval t, so that the ratio of the difference between the current SOC value of the power battery and the previous SOC value to the time interval t may be used as the SOC value change rate of the power battery 3.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after the minimum output power Pmin corresponding to the optimal economic region of the engine is determined, the power generation of the sub-motor 5 may be adjusted according to the relationship between the entire vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine and the SOC value change rate of the power battery.

Therefore, when the hybrid electric vehicle runs at a low speed, the engine is enabled to work in an economic area, so that the oil consumption can be reduced, the noise of the engine is reduced, the economical performance of the whole vehicle is improved, and when the hybrid electric vehicle runs at a low speed, the engine can only generate electricity and not participate in driving.

The specific adjustment mode of the power generation of the auxiliary motor according to the relation between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine and the change rate of the SOC value of the power battery after the auxiliary motor enters the power generation adjustment mode is further described below.

Specifically, when the engine drives the auxiliary motor to generate power and the power motor outputs driving force to wheels of the hybrid electric vehicle, the whole vehicle driving power P11 and the electric equipment power P21 are obtained in real time to obtain the whole vehicle required power P2 of the hybrid electric vehicle, and the whole vehicle required power P2 of the hybrid electric vehicle is judged, wherein the whole vehicle required power P2 can meet the following three conditions.

The first case is: the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine; the second case is: the required power P2 of the whole vehicle is larger than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine and smaller than or equal to the maximum allowable power generation power Pmax of the auxiliary motor; the third case is: the required power P2 of the whole vehicle is larger than the maximum allowable power generation power Pmax of the auxiliary motor.

In one embodiment of the first case, when the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery, and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, wherein if the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, the engine is controlled to generate electricity with the minimum output power Pmin so as to adjust the generated power of the auxiliary motor; if the charging power P3 of the power battery is greater than or equal to the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and the engine is controlled to generate electricity according to the obtained output power so as to adjust the generated power P1 of the auxiliary motor.

It should be noted that, the first relation table between the SOC value change rate of the power battery and the charging power P3 of the power battery may be pre-stored, so that after the SOC value change rate of the power battery is obtained, the charging power P3 of the corresponding power battery may be obtained by comparing the first relation table. The SOC value change rate of the power battery and the charging power P3 of the power battery satisfy the relationship shown in table 1 above.

As shown in table 1, when the obtained SOC value change rate is A1, the obtained charging power P3 of the corresponding power battery is B1; when the obtained change rate of the SOC value is A2, the obtained charging power P3 of the corresponding power battery is B2; when the obtained change rate of the SOC value is A3, the obtained charging power P3 of the corresponding power battery is B3; when the obtained change rate of the SOC value is A4, the obtained charging power P3 of the corresponding power battery is B4; when the obtained SOC value change rate is A5, the obtained charging power P3 of the corresponding power battery is B5.

Specifically, after the auxiliary motor enters the generated power adjustment mode, the whole vehicle driving power P11 and the electric equipment power P21 are obtained in real time to obtain the whole vehicle required power P2 of the hybrid electric vehicle, and the whole vehicle required power P2 of the hybrid electric vehicle is judged. When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, the charging power P3 of the power battery can be obtained according to the SOC value change rate of the power battery, and whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle is judged.

When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, if the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, namely P3 is smaller than Pmin-P2, the engine is controlled to generate electricity at the minimum output power Pmin so as to adjust the generated power of the auxiliary motor 1; if the charging power P3 of the power battery is greater than or equal to the difference between the minimum output power Pmin and the whole vehicle required power P2, namely, the P3 is more than or equal to Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the whole vehicle required power P2, and the power generation of the auxiliary motor is adjusted by controlling the engine to generate power according to the obtained output power.

Therefore, when the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, the power generation power of the engine is obtained according to the relationship between the charging power P3 of the power battery and the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the required power P2 of the whole vehicle, so that the engine runs in the preset optimal economic area, and the engine only generates power without participating in driving, thereby reducing the oil consumption of the engine and reducing the noise of the engine.

In one embodiment of the second case, when the vehicle demand power P2 is equal to or greater than the minimum output power Pmin corresponding to the optimal economy area of the engine and equal to or less than the maximum allowable power generation power Pmax of the sub-motor, the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery, the output power of the engine in the preset optimal economy area is obtained according to the sum of the charging power P3 of the power battery and the vehicle demand power P2, and the power generation is performed by controlling the engine to generate the power with the obtained output power so as to adjust the power generation power P1 of the sub-motor.

Specifically, when the required power P2 of the whole vehicle is greater than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine and less than the maximum allowable power Pmax of the auxiliary motor, the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery when the engine is controlled to work in the preset optimal economic area, and the output power of the engine in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, wherein the obtained output power=p3+p2. Further, the engine is controlled to generate power at the obtained output power to adjust the generated power P1 of the sub-motor, thereby increasing the SOC value of the power battery and operating the engine in a preset optimal economy region.

Therefore, when the required power P2 of the whole vehicle is larger than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine and smaller than the maximum allowable power Pmax of the auxiliary motor, the output power of the engine is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, so that the engine runs in the preset optimal economic area, and the engine only generates power without participating in driving, thereby reducing the oil consumption of the engine and reducing the noise of the engine.

In one embodiment of the third case, when the vehicle-mounted required power P2 is greater than the maximum allowable generated power Pmax of the sub-electric motor, the engine is also controlled to participate in driving so that the engine outputs power to the wheels through the clutch.

Specifically, when the vehicle demand power P2 is greater than the maximum allowable power P max of the sub-motor, that is, the vehicle demand power P2 of the hybrid vehicle is greater than the power P1 of the sub-motor, the engine is further controlled to output driving force to the wheels through the clutch so as to enable the engine to participate in driving, so that part of the driving power P' is borne by the engine, thereby reducing the demand for the power P1 of the sub-motor and enabling the engine to operate in a preset optimal economic area.

Therefore, when the required power P2 of the whole vehicle is larger than the maximum allowable generated power Pmax of the auxiliary motor, the power battery discharges outwards to supply power for the power motor, and at the moment, the engine and the power motor are controlled to output power to wheels of the hybrid electric vehicle at the same time, so that the engine works in a preset optimal economic area.

As described above, as shown in fig. 17, the power generation control method of the hybrid vehicle according to the embodiment of the invention specifically includes the steps of:

s201: the SOC value M of the power battery and the vehicle speed V of the hybrid vehicle are obtained.

S202: it is determined whether the vehicle speed V of the hybrid vehicle is smaller than a first preset vehicle speed V1.

If yes, go to step S203; if not, step S204 is performed.

S203: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, step S207 is performed; if not, step S206 is performed.

S204: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, step S205 is performed; if not, step S206 is performed.

S205: the engine is controlled to participate in driving.

S206: the engine is controlled not to drive the auxiliary motor to generate power.

S207: and acquiring the depth D of an accelerator pedal of the hybrid electric vehicle and the whole vehicle resistance F of the hybrid electric vehicle.

S208: whether the depth D of the accelerator pedal is larger than a first preset depth D1 or whether the whole vehicle resistance F of the hybrid electric vehicle is larger than the first preset resistance F1 or whether the SOC value M of the power battery is smaller than a preset limit value M2 is judged.

If yes, step S205 is performed; if not, step S209 is performed.

S209: and acquiring the whole vehicle required power P2 of the hybrid electric vehicle.

S210: and judging whether the required power P2 of the whole vehicle is smaller than or equal to the maximum allowable power Pmax of the auxiliary motor.

If yes, go to step S211; if not, step S205 is performed.

S211: the engine is controlled to drive the auxiliary motor to generate power, and the engine does not participate in driving.

At this time, the sub motor is controlled to enter the generated power adjustment mode.

S212: and judging whether the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine.

If yes, step S213 is performed; if not, step S214 is performed.

S213: the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery, and step S215 is performed.

S214: the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery, and step S216 is performed.

S215: and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle.

If yes, go to step S217; if not, step S216 is performed.

S216: and obtaining the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and generating electricity by controlling the engine to obtain the output power.

S217: the engine is controlled to generate power at the minimum output Pmin.

In summary, according to the power generation control method of the hybrid electric vehicle provided by the embodiment of the invention, the SOC value of the power battery and the speed of the hybrid electric vehicle are obtained, and the wage resetting machine is buckled according to the SOC value of the power battery and the speed of the hybrid electric vehicle to enter a power generation power regulation mode so as to enable the engine to run in a preset optimal economic area, thereby reducing the oil consumption of the engine, improving the running economy of the whole vehicle, reducing the noise of the engine, realizing various driving modes, maintaining the low-speed electric balance and the low-speed smoothness of the whole vehicle, and improving the performance of the whole vehicle.

Based on the hybrid electric vehicle and the power system thereof in the above embodiment, the embodiment of the invention also provides a power generation control method of the hybrid electric vehicle.

Fig. 18 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 18, the power generation control method of the hybrid vehicle includes the steps of:

s100: and acquiring the SOC value of the power battery and the speed of the hybrid electric vehicle.

S200: and controlling the power generation P1 of the auxiliary motor according to the SOC value of the power battery and the speed of the hybrid electric vehicle.

S300: and obtaining the power generation power of the engine of the hybrid electric vehicle according to the power generation power of the auxiliary motor so as to control the engine to run in a preset optimal economic area, wherein the auxiliary motor generates power under the drive of the engine.

It should also be noted that the predetermined optimal economy area of the engine may be determined in conjunction with the engine universal map. An example of an engine universal characteristic curve is shown in fig. 7, in which the ordinate on the side is the output torque of the engine, the abscissa is the rotational speed of the engine, and curve a is the fuel economy curve of the engine. The region corresponding to the fuel economy curve is the optimal economy region of the engine, namely, when the torque and the torque of the engine are positioned on the optimal fuel economy curve of the engine, the engine is in the optimal economy region. Thus, in an embodiment of the present invention, the engine may be operated in a preset optimal economy region by controlling the rotational speed and output torque of the engine to fall on an engine fuel economy curve, such as curve a.

Further, according to an embodiment of the present invention, during the running of the hybrid vehicle, the SOC value of the power battery and the vehicle speed V of the hybrid vehicle are obtained, and the power generation P1 of the sub motor is controlled according to the SOC value of the power battery and the vehicle speed V of the hybrid vehicle, and the power generation P0 of the engine 1 is obtained according to the power generation P1 of the sub motor to control the engine to run in a preset optimal economy region.

When the engine drives the auxiliary motor to generate power, the SOC value of the power battery and the speed of the hybrid electric vehicle can be obtained first, then the power generation P1 of the auxiliary motor is controlled according to the SOC value of the power battery and the speed of the hybrid electric vehicle, and the power generation P0 of the engine 1 is obtained according to the power generation P1 of the auxiliary motor so as to control the engine to run in a preset optimal economic area. On the premise that the engine works in a preset optimal economic area, the power of the engine for driving the auxiliary motor to generate electricity is determined, so that the power of the auxiliary motor is adjusted.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value, if the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, the generated power P1 of the sub-motor is controlled.

Specifically, after the SOC value of the power battery and the vehicle speed V of the hybrid vehicle are obtained, the interval in which the SOC value of the power battery is located may be determined, if the SOC value of the power battery is located in the medium electric quantity interval, the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery may be charged, at this time, it is further determined whether the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, if the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, the power generation P1 of the sub-motor 5 is controlled, at this time, the vehicle speed of the hybrid vehicle is lower, the required driving force is less, the power motor is sufficient to drive the hybrid vehicle to travel, and the engine may only drive the sub-motor to generate power, without participating in driving.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than the preset limit value M2 and equal to or less than the first preset value M1, and the vehicle speed V of the hybrid vehicle is less than the first preset vehicle speed V1, the vehicle-whole required power P2 of the hybrid vehicle is also obtained, and when the vehicle-whole required power P2 is equal to or less than the maximum allowable power generation Pmax of the sub-motor, the power generation P1 of the sub-motor is controlled.

Specifically, during the running of the hybrid electric vehicle, if the SOC value of the power battery is greater than the preset limit value M2 and less than or equal to the first preset value M1, and the vehicle speed V of the hybrid electric vehicle is less than the first preset vehicle speed V1, that is, the vehicle speed of the hybrid electric vehicle is low, the vehicle-whole demand power P2 of the hybrid electric vehicle is obtained, and when the vehicle-whole demand power P2 is less than or equal to the maximum allowable power generation Pmax of the sub-motor, the power generation power P1 of the sub-motor is controlled.

Still further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value M1, the vehicle speed V of the hybrid vehicle is less than a first preset vehicle speed V1, and the vehicle required power P2 of the hybrid vehicle is equal to or less than the maximum allowable power generation power Pmax of the sub-motor, the accelerator pedal depth D of the hybrid vehicle and the vehicle resistance F of the hybrid vehicle are also obtained, and when the accelerator pedal depth D is equal to or less than a first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than a first preset resistance F1, the power generation power P1 of the sub-motor is controlled.

Specifically, if the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value M1, the vehicle speed V of the hybrid vehicle is less than a first preset vehicle speed V1, and the vehicle required power P2 of the hybrid vehicle is equal to or less than the maximum allowable power generation Pmax of the auxiliary motor, the accelerator pedal depth D of the hybrid vehicle and the vehicle resistance F of the hybrid vehicle are obtained in real time, and when the accelerator pedal depth D is equal to or less than the first preset depth D1 and the vehicle resistance F of the hybrid vehicle is equal to or less than the first preset resistance F1, the hybrid vehicle is illustrated to operate in a low-speed mode, and the power generation P1 of the auxiliary motor is controlled.

According to one embodiment of the present invention, when controlling the engine to drive the sub-motor alone to generate electricity and controlling the power motor to output the driving force alone, the generated power P0 of the engine is obtained according to the following formula:

P0＝P1/η/ζ

wherein, P1 represents the power generated by the auxiliary motor, eta represents the belt transmission efficiency, and ζ represents the efficiency of the auxiliary motor.

That is, in the case where the engine can generate only without being involved in driving, the power generation power P0 of the engine can be calculated from the power generation power of the sub-motor, the belt transmission efficiency η, and the efficiency ζ of the sub-motor, and the engine is controlled to drive the sub-motor to generate power with the obtained power generation power P0, so as to control the power generation power of the sub-motor.

And when the SOC value of the power battery is equal to or less than a preset limit value M2, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch; when the SOC value of the power battery is smaller than or equal to a first preset value M1, the speed V of the hybrid electric vehicle is smaller than the first preset speed V1, and the depth D of the accelerator pedal is larger than a first preset depth D1, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch; when the SOC value of the power battery is smaller than or equal to a first preset value M1, the speed V of the hybrid electric vehicle is smaller than the first preset speed V1, and the whole vehicle resistance F of the hybrid electric vehicle is larger than the first preset resistance F1, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch.

According to one embodiment of the invention, after the auxiliary motor enters the generated power adjustment mode, the generated power P1 of the auxiliary motor is controlled according to the whole vehicle required power P2 of the hybrid electric vehicle and the charging power P3 of the power battery.

According to one embodiment of the present invention, the formula for controlling the generated power P1 of the sub-motor according to the whole vehicle required power P2 of the hybrid vehicle and the charged power P3 of the power battery is as follows:

P1=p2+p3, wherein p2=p11+p21,

It should be noted that the electrical devices may include a first electrical device and a second electrical device, that is, the electrical device power P21 may include power required by the high voltage electrical device and the low voltage electrical device.

It should be further noted that the whole vehicle driving power P11 may include the output power of the power motor 2, and the whole vehicle driving power P11 may be obtained according to a preset accelerator-torque curve of the power motor and a rotation speed of the power motor, where the preset accelerator-torque curve may be determined when the power of the hybrid electric vehicle is matched. In addition, the electrical equipment power P21 can be obtained in real time according to the electrical equipment running on the whole car, for example, the electrical equipment power P21 is calculated through the DC consumption on the bus. Further, the charging power P3 of the power battery may be obtained from the SOC value of the power battery. Assuming that the vehicle driving power p11=b1 kw, the electric device power p21=b2 kw, and the charging power p3=b3 kw of the power battery, the generated power of the sub-motor=b1+b2+b3.

Specifically, during the running of the hybrid electric vehicle, the charging power P3 of the power battery, the driving power P11 of the whole vehicle, and the power P21 of the electric device may be obtained, and the sum of the charging power P3 of the power battery, the driving power P11 of the whole vehicle, and the power P21 of the electric device is taken as the power generation power P1 of the sub motor, so that the power generation power of the sub motor may be controlled according to the calculated P1 value, for example, the output torque and the rotation speed of the engine may be controlled according to the calculated P1 value, so as to control the power generated by the sub motor driven by the engine.

Further, according to an embodiment of the present invention, the adjustment of the generated power of the sub motor includes: and acquiring the SOC value change rate of the power battery, and controlling the power generation power of the auxiliary motor according to the relation between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic area of the engine and the SOC value change rate of the power battery.

Specifically, the optimal economic region of the engine may be determined based on the engine universal characteristic curve shown in fig. 7, and the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after the minimum output power Pmin corresponding to the optimal economic region of the engine is determined, the power generation of the sub-motor 5 may be controlled based on the relationship between the entire vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine and the SOC value change rate of the power battery.

The specific adjustment mode of controlling the power generation of the auxiliary motor according to the relationship between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine and the SOC value change rate of the power battery after the auxiliary motor enters the power generation adjustment mode is further described below.

In one embodiment of the first case, when the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery, and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, wherein if the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, the engine is controlled to generate electricity with the minimum output power Pmin so as to control the generated power of the auxiliary motor; if the charging power P3 of the power battery is greater than or equal to the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and the engine is controlled to generate electricity according to the obtained output power so as to control the generated power P1 of the auxiliary motor.

Specifically, when the auxiliary motor is controlled to generate power, the driving power P11 of the whole vehicle and the power P21 of the electrical equipment are obtained in real time to obtain the required power P2 of the whole vehicle of the hybrid electric vehicle, and the required power P2 of the whole vehicle of the hybrid electric vehicle is judged. When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, the charging power P3 of the power battery can be obtained according to the SOC value change rate of the power battery, and whether the charging power P3 of the power battery is smaller than or equal to the difference between the minimum output power Pmin and the required power P2 of the whole vehicle is judged.

When the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine, if the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle, namely P3 is smaller than Pmin-P2, the engine is controlled to generate electricity by the minimum output power Pmin so as to control the generated power of the auxiliary motor 1; if the charging power P3 of the power battery is greater than or equal to the difference between the minimum output power Pmin and the whole vehicle required power P2, namely, the P3 is more than or equal to Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the whole vehicle required power P2, and the power generation of the auxiliary motor is controlled by controlling the engine to generate power according to the obtained output power.

In one embodiment of the second case, when the vehicle demand power P2 is equal to or greater than the minimum output power Pmin corresponding to the optimal economy area of the engine and equal to or less than the maximum allowable power generation power Pmax of the sub-motor, the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery, the output power of the engine in the preset optimal economy area is obtained according to the sum of the charging power P3 of the power battery and the vehicle demand power P2, and the power generation is performed by controlling the engine to generate the power with the obtained output power to control the power generation power P1 of the sub-motor.

Specifically, when the required power P2 of the whole vehicle is greater than or equal to the minimum output power Pmin corresponding to the optimal economic area of the engine and less than the maximum allowable power Pmax of the auxiliary motor, the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery when the engine is controlled to work in the preset optimal economic area, and the output power of the engine in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, wherein the obtained output power=p3+p2. Further, the engine is controlled to generate power at the obtained output power to control the generated power P1 of the sub-motor, thereby increasing the SOC value of the power battery and operating the engine in a preset optimal economy region.

Therefore, when the required power P2 of the whole vehicle is larger than the maximum allowable generated power Pmax of the auxiliary motor, the power battery discharges outwards to supply power to the power motor, and at the moment, the power motor is controlled to output power to wheels of the hybrid electric vehicle so that the engine works in a preset optimal economic area.

As described above, as shown in fig. 19, the power generation control method of the hybrid vehicle according to the embodiment of the invention specifically includes the steps of:

s301: the SOC value M of the power battery and the vehicle speed V of the hybrid vehicle are obtained.

S302: it is determined whether the vehicle speed V of the hybrid vehicle is smaller than a first preset vehicle speed V1.

If yes, step S303 is performed; if not, step S304 is performed.

S303: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, step S307 is executed; if not, step S306 is performed.

S304: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, step S305 is performed; if not, step S306 is performed.

S305: the engine is controlled to participate in driving.

S306: the engine is controlled not to drive the auxiliary motor to generate power.

S307: and acquiring the depth D of an accelerator pedal of the hybrid electric vehicle and the whole vehicle resistance F of the hybrid electric vehicle.

S308: whether the depth D of the accelerator pedal is larger than a first preset depth D1 or whether the whole vehicle resistance F of the hybrid electric vehicle is larger than the first preset resistance F1 or whether the SOC value M of the power battery is smaller than a preset limit value M2 is judged.

If yes, step S305 is performed; if not, step S309 is performed.

S309: and acquiring the whole vehicle required power P2 of the hybrid electric vehicle.

S310: and judging whether the required power P2 of the whole vehicle is smaller than or equal to the maximum allowable power Pmax of the auxiliary motor.

If yes, go to step S311; if not, step S305 is performed.

S311: the engine is controlled to drive the auxiliary motor to generate power, and the engine does not participate in driving.

S312: and judging whether the required power P2 of the whole vehicle is smaller than the minimum output power Pmin corresponding to the optimal economic area of the engine.

If yes, step S313 is performed; if not, step S314 is performed.

S313: the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery, and step S315 is performed.

S314: the charging power P3 of the power battery is obtained according to the SOC value change rate of the power battery, and step S316 is performed.

S315: and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin and the required power P2 of the whole vehicle.

If yes, go to step S317; if not, step S316 is performed.

S316: and obtaining the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and generating electricity by controlling the engine to obtain the output power.

S317: the engine is controlled to generate power at the minimum output Pmin.

Fig. 20 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 20, the power generation control method of the hybrid vehicle includes the steps of:

s21: acquiring an SOC value of a power battery of the hybrid electric vehicle, a speed of the hybrid electric vehicle and an SOC value of a low-voltage storage battery of the hybrid electric vehicle;

the SOC value of the power battery and the SOC value of the low-voltage battery may be acquired by a battery management system of the hybrid vehicle so that the SOC value of the power battery and the SOC value of the low-voltage battery are acquired.

S22: controlling a secondary motor of the hybrid electric vehicle to enter a power generation power adjusting mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable an engine of the hybrid electric vehicle to run in a preset optimal economic area, wherein the secondary motor generates power under the drive of the engine;

the power generation power adjusting mode is a mode for adjusting the power generation power of the engine, and in the power generation power adjusting mode, the engine can be controlled to drive the auxiliary motor to generate power so as to adjust the power generation power of the auxiliary motor.

S23: and after the auxiliary motor enters a generated power adjusting mode, adjusting the generated power of the auxiliary motor according to the SOC value of the low-voltage storage battery.

When the engine drives the auxiliary motor to generate power, the SOC value of the power battery and the speed of the hybrid electric vehicle can be obtained first, and then the auxiliary motor is controlled to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle, so that the engine works in a preset optimal economic area. In the generated power adjustment mode, the generated power of the sub motor can be adjusted on the premise that the engine is operated in a preset optimal economic area. After the auxiliary motor enters a generated power adjusting mode, the generated power of the auxiliary motor is further adjusted according to the SOC value of the low-voltage storage battery.

Therefore, the engine can work in the preset optimal economic area, and the oil consumption of the engine in the preset optimal economic area is the lowest, and the fuel economy is the highest, so that the oil consumption of the engine can be reduced, the noise of the engine is reduced, and the running economy of the whole vehicle is improved. In addition, the auxiliary motor has higher power generation power and power generation efficiency during low-speed running, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power motor and the high-voltage electrical equipment can be guaranteed to be powered by charging the power battery, so that the power motor can be guaranteed to drive the whole vehicle to run normally, and the low-voltage electrical equipment can be guaranteed to be powered by charging the low-voltage storage battery, and the low-voltage power supply of the whole vehicle can be realized through the low-voltage storage battery when the auxiliary motor stops generating power and the power battery fails or is insufficient in electric quantity, so that the whole vehicle can be guaranteed to run in a pure fuel mode, and the running mileage of the whole vehicle is improved.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value, the sub-motor is controlled to enter the generated power adjustment mode if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed.

Specifically, after the SOC value of the power battery and the vehicle speed of the hybrid electric vehicle are obtained, the interval in which the SOC value of the power battery is located may be determined, if the SOC value of the power battery is in the second electric quantity interval, the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery may be charged, at this time, whether the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed is further determined, if the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed, the sub-motor is controlled to enter the generated power adjustment mode, at this time, the vehicle speed of the hybrid electric vehicle is lower, the required driving force is less, the power motor is sufficient to drive the hybrid electric vehicle to travel, and the engine may only drive the sub-motor to generate power without participating in driving.

Further, when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, and the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed, the vehicle demand power of the hybrid electric vehicle is also obtained, and when the vehicle demand power is less than or equal to the maximum allowable power generation power of the auxiliary motor, the auxiliary motor is controlled to enter a power generation power adjustment mode.

That is, after judging that the SOC value of the power battery is greater than the preset limit value and less than or equal to the first preset value, and the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed, it may be further judged whether the required power of the whole vehicle is greater than the maximum allowable power generation of the sub-motor, if the required power of the whole vehicle is less than or equal to the maximum allowable power generation of the sub-motor, the sub-motor is controlled to enter the power generation adjustment mode, at this time, the required driving force of the whole vehicle is less, and the required power of the whole vehicle is less, the power motor is sufficient to drive the hybrid electric vehicle to run, and the engine can only drive the sub-motor to generate power and does not participate in driving.

Further, when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, the speed of the hybrid electric vehicle is less than a first preset speed, and the required power of the whole vehicle is less than or equal to the maximum allowable generated power of the auxiliary motor, the accelerator pedal depth of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are also obtained, and when the accelerator pedal depth is less than or equal to the first preset depth and the whole vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the auxiliary motor is controlled to enter the generated power adjusting mode.

That is, after judging that the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, and the vehicle speed of the hybrid electric vehicle is less than a first preset vehicle speed, and the vehicle required power is less than or equal to the maximum allowable generated power of the auxiliary motor, it may be further judged whether the depth of the accelerator pedal is greater than a first preset depth and the vehicle resistance of the hybrid electric vehicle is greater than the first preset resistance, if the depth of the accelerator pedal is less than or equal to the first preset depth and the vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the auxiliary motor is controlled to enter the generated power adjustment mode, at this time, the required driving force of the vehicle is less, the vehicle required power is less, the depth of the accelerator pedal is also less, the power motor is sufficient to drive the hybrid electric vehicle, and the engine can only drive the auxiliary motor to generate power and not participate in driving.

As described above, when the hybrid electric vehicle runs at a low speed, the engine can only generate electricity and does not participate in driving, and the clutch is not needed because the engine does not participate in driving, so that the clutch wear or sliding wear can be reduced, meanwhile, the setback is reduced, the comfort is improved, and the engine is enabled to work in an economic area at a low speed.

In addition, according to an embodiment of the present invention, when the SOC value of the power battery is smaller than a preset limit value, or the vehicle speed of the hybrid vehicle is equal to or greater than a first preset vehicle speed, or the vehicle required power is greater than the maximum allowable generated power of the sub-motor, or the accelerator pedal depth is greater than a first preset depth, or the vehicle resistance of the hybrid vehicle is greater than a first preset resistance, the engine is controlled to participate in driving.

That is, when the SOC value of the power battery is smaller than a preset limit value, or the vehicle speed of the hybrid vehicle is greater than or equal to a first preset vehicle speed, or the required power of the whole vehicle is greater than the maximum allowable generated power of the auxiliary motor, or the depth of the accelerator pedal is greater than a first preset depth, or the resistance of the whole vehicle of the hybrid vehicle is greater than the first preset resistance, the control module controls the engine to participate in driving, at this time, the power battery is no longer discharged, the required driving force of the whole vehicle is greater, the required power of the whole vehicle is greater, the depth of the accelerator pedal is greater, or the resistance of the whole vehicle is also greater, the power motor is insufficient to drive the hybrid vehicle to run, and the engine participates in driving to perform complementary driving.

More specifically, when the vehicle-mounted required power is greater than the maximum allowable generated power of the sub-motor, the engine is also controlled to participate in driving so that the engine outputs power to wheels of the hybrid vehicle through the clutch.

And when the SOC value of the power battery is smaller than or equal to a preset limit value, the engine is also controlled to participate in driving so that the engine outputs power to wheels of the hybrid electric vehicle through the clutch; when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the depth of the accelerator pedal is larger than the first preset depth, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch; when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the whole vehicle resistance of the hybrid electric vehicle is larger than the first preset resistance, the engine is also controlled to participate in driving so that the engine outputs power to wheels through the clutch.

That is, the SOC value of the power battery, the accelerator pedal depth, the vehicle speed, the vehicle resistance and the vehicle-mounted power demand of the hybrid vehicle can be obtained in real time, and the SOC value of the power battery, the accelerator pedal depth, the vehicle speed and the vehicle-mounted resistance of the hybrid vehicle are determined:

firstly, when the SOC value of the power battery is smaller than a preset limit value, the power battery cannot provide enough electric energy because the electric quantity of the power battery is too low, the engine and the power motor are controlled to participate in driving simultaneously, the engine can be controlled to drive the auxiliary motor to generate electricity so as to charge the power battery, the engine can be controlled to drive the auxiliary motor to generate electricity at the moment, and the engine can work in a preset optimal economic area by adjusting the power generation power of the auxiliary motor.

Secondly, when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the depth of the accelerator pedal is larger than the first preset depth, the control module controls the engine and the power motor to participate in driving simultaneously, at the moment, the engine can be controlled to drive the auxiliary motor to generate electricity, and the engine can work in a preset optimal economic area by adjusting the power generation power of the auxiliary motor.

Thirdly, when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed and the whole vehicle resistance of the hybrid electric vehicle is larger than the first preset resistance, the engine and the power motor can be controlled to participate in driving simultaneously due to the fact that the whole vehicle resistance is larger, the engine can be controlled to drive the auxiliary motor to generate electricity at the moment, and the engine can work in a preset optimal economic area by adjusting the power generation power of the auxiliary motor.

Therefore, the engine can participate in driving when the driving force output by the power motor is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved. In addition, the engine can be controlled to work in an economic area, and the fuel consumption of the engine 1 in a preset optimal economic area is the lowest, so that the fuel consumption can be reduced, the engine noise can be reduced, and the economic performance of the whole vehicle can be improved.

In addition, the control module is also used for: when the SOC value of the power battery is smaller than or equal to a preset limit value and the speed of the hybrid electric vehicle is larger than a first preset speed, the engine is controlled to participate in driving so that the engine outputs power to wheels through a clutch.

Of course, it should be understood that the control module is also configured to: when the SOC value of the power battery is larger than a first preset value, the engine does not drive the auxiliary motor to generate power, and at the moment, the electric quantity of the power battery is close to full power, charging is not needed, and the engine does not drive the auxiliary motor to generate power. That is, when the power of the power battery is close to full power, the engine does not drive the auxiliary motor to generate power, so that the auxiliary motor does not charge the power battery.

Further, after the sub-motor enters the electric power adjustment mode, the generated power of the sub-motor may be adjusted, and the generated power adjustment process according to the embodiment of the present invention will be described in detail.

According to one embodiment of the invention, after the auxiliary motor enters the generated power adjusting mode, the generated power of the auxiliary motor is adjusted according to the whole vehicle required power of the hybrid electric vehicle, the charging power of the power battery, the charging power of the low-voltage storage battery and the SOC value of the low-voltage storage battery.

Specifically, the formula for adjusting the power generation of the sub motor according to the whole vehicle required power of the hybrid electric vehicle, the charging power of the power battery and the charging power of the low-voltage storage battery is as follows:

P1=p2+p3+p4, wherein p2=p11+p21,

p1 is the power generated by the auxiliary motor, P2 is the power required by the whole vehicle, P3 is the charging power of the power battery, P4 is the charging power of the low-voltage storage battery, P11 is the power for driving the whole vehicle, and P21 is the power of the electrical equipment.

It should be further noted that the whole vehicle driving power P11 may include an output power of a power motor, and the whole vehicle driving power P11 may be obtained according to a preset accelerator-torque curve of the power motor and a rotation speed of the power motor, where the preset accelerator-torque curve may be determined when the power of the hybrid electric vehicle is matched; the power P21 of the electrical equipment can be obtained in real time according to the electrical equipment running on the whole car, for example, the power P21 of the electrical equipment is calculated through DC consumption on a bus; the charging power P3 of the power battery may be obtained according to the SOC value of the power battery, and the charging power P4 of the low-voltage battery may be obtained according to the SOC value of the low-voltage battery.

Specifically, during the running of the hybrid electric vehicle, the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery, the entire vehicle driving power P11 and the electric equipment power P21 may be obtained, and the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery, the entire vehicle driving power P11 and the electric equipment power P21 is used as the power generation power P1 of the sub motor, so that the power generation power of the sub motor may be adjusted according to the calculated P1 value, for example, the output torque and the rotation speed of the engine may be controlled according to the calculated P1 value, so as to adjust the power generated by the sub motor of the engine.

Further, according to an embodiment of the present invention, the adjustment of the generated power of the sub motor includes: and acquiring the SOC value change rate of the power battery, and adjusting the power generation power of the auxiliary motor according to the relation between the required power of the whole vehicle and the minimum output power corresponding to the optimal economic area of the engine, and the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery and the SOC value change rate of the low-voltage storage battery.

It should be understood that the SOC value change rate of the power battery may be obtained according to the SOC value of the power battery, for example, the SOC value of the power battery is collected once every time interval t, so that the ratio of the difference between the current SOC value of the power battery and the previous SOC value to the time interval t may be used as the SOC value change rate of the power battery. Similarly, the SOC value change rate of the low-voltage battery may be obtained according to the SOC value of the low-voltage battery, for example, the SOC value of the low-voltage battery is collected once every time interval t, so that the ratio of the difference between the current SOC value of the low-voltage battery and the previous SOC value to the time interval t may be used as the SOC value change rate of the low-voltage battery.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power corresponding to the optimal economic region of the engine may be obtained, and after the minimum output power corresponding to the optimal economic region of the engine is determined, the power generation power of the sub-motor may be adjusted according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine, and the SOC value change rate of the power battery, the SOC value of the low-voltage battery, and the SOC value change rate of the low-voltage battery.

The specific control manner of adjusting the power generation of the sub-motor according to the relationship between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine, the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery, and the SOC value change rate of the low-voltage storage battery after the sub-motor 5 enters the power generation adjustment mode will be further described.

Specifically, when the SOC value of the low-voltage storage battery is larger than a preset low-power threshold value, acquiring the charging power of the power battery according to the SOC value change rate of the power battery, and judging whether the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, wherein if the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, the power generation of the auxiliary motor is regulated by controlling the engine to generate power at the minimum output power; if the charging power of the power battery is greater than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the output power of the engine in the preset optimal economic area is obtained according to the sum of the charging power of the power battery and the required power of the whole vehicle, and the power generation of the auxiliary motor is adjusted by controlling the engine to generate power according to the obtained output power.

Specifically, when the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-power threshold value, acquiring the SOC value change rate of the low-voltage storage battery and the SOC value change rate of the power battery, acquiring the charging power of the low-voltage storage battery according to the SOC value change rate of the low-voltage storage battery, acquiring the charging power of the power battery according to the SOC value change rate of the power battery, judging whether the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, and if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, generating power of the auxiliary motor is regulated by controlling the engine to generate power with the minimum output power; and if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is greater than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, acquiring the output power of the engine in the preset optimal economic area according to the sum of the charging power of the power battery, the charging power of the low-voltage storage battery and the required power of the whole vehicle, and generating power by controlling the engine to acquire the output power so as to adjust the power generation power of the auxiliary motor.

It should be noted that, the first relation table between the SOC value change rate of the power battery and the charging power P3 of the power battery may be pre-stored in the control module, so that after the SOC value change rate of the power battery is obtained, the charging power P3 of the corresponding power battery may be obtained by comparing the first relation table. For example, a first table of the relationship between the SOC value change rate of the power battery and the charging power P3 of the power battery may be as shown in table 1 above.

As can be seen from the above table 1, when the SOC value change rate of the power battery is A1, the charging power P3 of the corresponding power battery is B1; when the change rate of the SOC value of the power battery is A2, the charging power P3 of the corresponding power battery is B2; when the change rate of the SOC value of the power battery is A3, the charging power P3 of the corresponding power battery is B3; when the change rate of the SOC value of the power battery is A4, the charging power P3 of the corresponding power battery is B4; when the change rate of the SOC value of the power battery is A5, the charging power P3 of the corresponding power battery is B5.

Similarly, a second relation table between the SOC value change rate of the low-voltage storage battery and the charging power P4 of the low-voltage storage battery may be pre-stored in the control module, so that after the SOC value change rate of the low-voltage storage battery is obtained, the charging power P4 of the corresponding low-voltage storage battery may be obtained by comparing the second relation table. For example, a first table of the relationship between the SOC value change rate of the low-voltage battery and the charging power P4 of the low-voltage battery may be as shown in table 2 above.

As can be seen from table 2, when the SOC value change rate of the low-voltage battery is a11, the charging power P4 of the corresponding low-voltage battery is B11; when the change rate of the SOC value of the low-voltage storage battery is A12, the charging power P4 of the corresponding low-voltage storage battery is B12; when the change rate of the SOC value of the low-voltage storage battery is A13, the charging power P4 of the corresponding low-voltage storage battery is B13; when the change rate of the SOC value of the low-voltage storage battery is A14, the charging power P4 of the corresponding low-voltage storage battery is B14; when the SOC value change rate of the low-voltage storage battery is a15, the charging power P4 of the corresponding low-voltage storage battery is B15.

Specifically, after the auxiliary power 5 enters the electric power adjustment mode, the SOC value of the low-voltage storage battery, the SOC value of the power battery, and the vehicle-required power P2 (the sum of the vehicle driving power P11 and the electric device power P21) may be obtained, and then, it is determined whether the SOC value of the low-voltage storage battery is greater than a preset low-battery threshold.

If the SOC value of the low-voltage storage battery is larger than a preset low-power threshold value, acquiring the SOC value change rate of the power battery, inquiring the charging power P3 of the power battery corresponding to the SOC value change rate of the power battery, selecting proper charging power P3 to enable the SOC value of the power battery to rise, further judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2, if so, that is, if P3 is smaller than Pmin-P2, generating power by controlling the engine by the minimum output power Pmin to regulate the power generation power of the auxiliary motor, namely controlling the engine to run at the minimum output power Pmin corresponding to the optimal economic area, and charging the power of the power battery by subtracting the power of the whole vehicle required power P2 from the minimum output power Pmin corresponding to the optimal economic area, that is Pmin-P2; if the power consumption is not less than or equal to P3, namely P3 is more than or equal to Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, the engine is controlled to generate power by the obtained output power so as to adjust the power generation power of the auxiliary motor, namely the corresponding output power is searched in the preset optimal economic area of the engine, the obtained output power can be the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, namely (P2+P3 or P11+P21+P3), and the engine is controlled to generate power by the obtained output power.

If the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-power threshold value, acquiring the SOC value change rate of the power battery, inquiring the charging power P3 of the power battery corresponding to the SOC value change rate of the power battery, selecting proper charging power P3 to enable the SOC value of the power battery to rise, acquiring the SOC value change rate of the low-voltage storage battery, inquiring the charging power P4 of the low-voltage storage battery corresponding to the SOC value change rate of the low-voltage storage battery, selecting proper charging power P4 to enable the SOC value of the low-voltage storage battery to rise, and further judging whether the sum of the charging power P4 of the low-voltage storage battery and the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2. If the power is smaller than P3+P4 and smaller than Pmin-P2, the engine is controlled to generate electricity at the minimum output power Pmin so as to regulate the power generation power of the auxiliary motor, namely the engine is controlled to run at the minimum output power Pmin corresponding to the optimal economic area, and the power of the power required by the whole vehicle P2 is subtracted from the minimum output power Pmin corresponding to the optimal economic area, namely Pmin-P2, so that the power battery and the low-voltage storage battery are charged; if the power is not less than P3+P4 is more than or equal to Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, the power generation of the auxiliary motor is regulated by controlling the engine to generate the obtained output power, namely, the corresponding output power is searched in the preset optimal economic area of the engine, and the obtained output power can be the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, namely (P2+P3+P4 or P11+P21+P3+P4), and the engine is controlled to generate power according to the obtained output power.

As described above, as shown in fig. 21, the power generation control method of the hybrid vehicle according to the embodiment of the invention includes the steps of:

s601: the SOC value M of the power battery and the vehicle speed V of the hybrid vehicle are obtained.

S602: it is determined whether the vehicle speed V of the hybrid vehicle is smaller than a first preset vehicle speed V1.

If yes, step S603 is performed; if not, step S604 is performed.

S603: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, go to step S607; if not, step S606 is performed.

S604: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, step S605 is executed; if not, step S606 is performed.

S605: the engine is controlled to participate in driving.

S606: the engine is controlled not to drive the auxiliary motor to generate power.

S607: and acquiring the depth D of an accelerator pedal of the hybrid electric vehicle and the whole vehicle resistance F of the hybrid electric vehicle.

S608: whether the depth D of the accelerator pedal is larger than a first preset depth D1 or whether the whole vehicle resistance F of the hybrid electric vehicle is larger than the first preset resistance F1 or whether the SOC value M of the power battery is smaller than a preset limit value M2 is judged.

If yes, step S605 is executed; if not, step S609 is performed.

S609: and acquiring the whole vehicle required power P2 of the hybrid electric vehicle.

S610: and judging whether the required power P2 of the whole vehicle is smaller than or equal to the maximum allowable power Pmax of the auxiliary motor.

If yes, step S611 is performed; if not, step S605 is performed.

S611: the engine is controlled to drive the auxiliary motor to generate power, and the engine does not participate in driving. At this time, the sub motor is controlled to enter the generated power adjustment mode.

S612: and judging whether the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-power threshold value.

If yes, go to step S617; if not, step S613 is performed.

S613: and acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery.

S614: and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2.

If yes, go to step S615; if not, step S616 is performed.

S615: the power generation of the sub-motor is regulated by controlling the engine to generate power at the minimum output power Pmin.

S616: and obtaining the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and generating electricity by controlling the engine to obtain the output power so as to regulate the power generation power of the auxiliary motor.

S617: and acquiring the charging power P4 of the low-voltage storage battery according to the SOC value change rate of the low-voltage storage battery.

S618: and acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery.

S619: and judging whether the sum of the charging power P4 of the low-voltage storage battery and the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2.

If yes, go to step S620; if not, step S621 is performed.

S620: the power generation of the sub-motor is regulated by controlling the engine to generate power at the minimum output power Pmin.

S621: and obtaining the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, and generating electricity by controlling the engine to obtain the output power so as to regulate the generated power of the auxiliary motor.

In summary, according to the power generation control method of the hybrid electric vehicle provided by the embodiment of the invention, the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle are obtained, the auxiliary motor is controlled to enter the power generation adjustment mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle, so that the engine runs in a preset optimal economic area, and after the auxiliary motor enters the power generation adjustment mode, the power generation of the auxiliary motor is adjusted according to the SOC value of the low-voltage storage battery, so that the engine is not involved in driving at a low speed, a clutch is not used, the abrasion or slipping of the clutch is reduced, meanwhile, the jerk is reduced, the comfort is improved, the engine can be operated in the economic area only, the power generation is not driven at a low speed, the oil consumption is reduced, the noise of the engine is reduced, the low-speed electric balance and the low-speed smoothness of the whole vehicle are maintained, and the performance of the whole vehicle is improved.

Fig. 22 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 22, the power generation control method of the hybrid vehicle includes the steps of:

S31: acquiring an SOC value of a power battery of the hybrid electric vehicle, a speed of the hybrid electric vehicle and an SOC value of a low-voltage storage battery of the hybrid electric vehicle;

S32: controlling the power generation power of a secondary motor of the hybrid electric vehicle according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle;

s33: and obtaining the power generation power of the engine of the hybrid electric vehicle according to the power generation power of the auxiliary motor so as to control the engine to run in a preset optimal economic area, wherein the auxiliary motor generates power under the drive of the engine.

Specifically, during the running process of the hybrid electric vehicle, the engine can output power to wheels of the hybrid electric vehicle through the clutch, and the engine can also drive the auxiliary motor to generate power. Therefore, the output power of the engine mainly comprises two parts, wherein one part is output to the auxiliary motor, namely the power generation power for driving the auxiliary motor to generate electricity, and the other part is output to the wheels, namely the driving power for driving the wheels.

When the engine drives the auxiliary motor to generate power, the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle can be used for controlling the power generation of the auxiliary motor according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle, and further obtaining the power generation of the engine according to the power generation of the auxiliary motor so as to control the engine to run in a preset optimal economic area. In other words, the control module may control the generated power of the sub-motor on the premise of operating the engine in a preset optimal economy area.

Therefore, the engine can work in the preset optimal economic area, and the oil consumption of the engine in the preset optimal economic area is the lowest, and the fuel economy is the highest, so that the oil consumption of the engine can be reduced, the noise of the engine is reduced, and the running economy of the whole vehicle is improved. In addition, the auxiliary motor has higher power generation power and power generation efficiency during low-speed running, so that the power consumption requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed smoothness of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power motor and the high-voltage electrical equipment can be guaranteed to be powered by charging the power battery, so that the power motor can be guaranteed to drive the whole vehicle to run normally, the low-voltage electrical equipment can be guaranteed to be powered by charging the low-voltage storage battery, and the low-voltage power supply of the whole vehicle can be realized through the low-voltage storage battery when the auxiliary motor stops generating power and the power battery fails or is insufficient in electric quantity, so that the whole vehicle can be guaranteed to run in a pure fuel mode, and the running mileage of the whole vehicle is improved.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value, if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the generated power of the sub-motor is controlled.

The first preset value may be an upper limit value of the SOC value of the power battery, which is set in advance, for example, a determination value of stopping charging, and may be preferably 30%. The preset limit value may be a preset lower limit value of the SOC value of the power battery, for example, a determination value of stopping the discharge, and may be preferably 10%. According to the first preset value and the preset limit value, the SOC value of the power battery can be divided into three sections, namely a first electric quantity section, a second electric quantity section and a third electric quantity section, when the SOC value of the power battery is smaller than or equal to the preset limit value, the SOC value of the power battery is in the first electric quantity section, and the power battery is only charged and not discharged at the moment; when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value, the SOC value of the power battery is in a second electric quantity interval, and at the moment, the power battery has a charging requirement, so that the power battery can be actively charged; when the SOC value of the power battery is larger than the first preset value, the SOC value of the power battery is in a third electric quantity interval, and the power battery can not be charged at the moment, namely, the power battery can not be actively charged.

Specifically, after the SOC value of the power battery and the vehicle speed of the hybrid electric vehicle are obtained, the interval in which the SOC value of the power battery is located may be determined, if the SOC value of the power battery is located in the middle electric quantity interval, the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, which indicates that the power battery may be charged, at this time, whether the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed is further determined, if the vehicle speed of the hybrid electric vehicle is less than the first preset vehicle speed, the generated power of the auxiliary motor is controlled, at this time, the vehicle speed of the hybrid electric vehicle is lower, the required driving force is less, the power motor is sufficient to drive the hybrid electric vehicle to travel, and the engine may only drive the auxiliary motor to generate power without participating in driving.

Therefore, the engine only generates electricity and does not participate in driving at low speed, so that the abrasion or sliding abrasion of the clutch can be reduced, the feeling of setbacks is reduced, and the comfort is improved.

Further, when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, and the speed of the hybrid electric vehicle is less than the first preset speed, the vehicle demand power of the hybrid electric vehicle is also obtained, and when the vehicle demand power is less than or equal to the maximum allowable power generation power of the auxiliary motor, the power generation power of the auxiliary motor is controlled.

That is, after it is determined that the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, and the vehicle speed of the hybrid electric vehicle is less than a first preset vehicle speed, it may be further determined whether the required power of the whole vehicle is greater than the maximum allowable power generation of the sub-motor, and if the required power of the whole vehicle is less than or equal to the maximum allowable power generation of the sub-motor, the power generation of the sub-motor is controlled, at this time, the required driving force of the whole vehicle is less, and the required power of the whole vehicle is less, the power motor is sufficient to drive the hybrid electric vehicle to travel, and the engine may only drive the sub-motor to generate power and not participate in driving.

Further, when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, the speed of the hybrid electric vehicle is less than a first preset speed, and the required power of the whole vehicle is less than or equal to the maximum allowable generated power of the auxiliary motor, the accelerator pedal depth of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are also obtained, and when the accelerator pedal depth is less than or equal to the first preset depth and the whole vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the generated power of the auxiliary motor is controlled.

That is, after judging that the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, and the vehicle speed of the hybrid electric vehicle is less than a first preset vehicle speed, and the vehicle required power is less than or equal to the maximum allowable generated power of the auxiliary motor, it may be further judged whether the depth of the accelerator pedal is greater than a first preset depth and the vehicle resistance of the hybrid electric vehicle is greater than the first preset resistance, if the depth of the accelerator pedal is less than or equal to the first preset depth and the vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the generated power of the auxiliary motor is controlled, at this time, the required driving power of the vehicle is less, the vehicle required power is less, the depth of the accelerator pedal is also less, the power motor is sufficient to drive the hybrid electric vehicle to travel, and the engine can only drive the auxiliary motor to generate power and not participate in driving.

As described above, when the hybrid electric vehicle runs at low speed, the engine can only generate electricity and not participate in driving, and the clutch is not needed because the engine does not participate in driving, so that the clutch wear or sliding wear can be reduced, meanwhile, the frustration is reduced, the comfort is improved, and the engine can work in an economic area at low speed.

According to one embodiment of the present invention, when the engine is controlled to independently drive the sub motor to generate electricity and the power motor is controlled to independently output driving force, the generated power of the engine is obtained according to the following formula:

P0＝P1/η/ζ

wherein, P0 is the power generated by the engine, P1 is the power generated by the auxiliary motor, eta belt transmission efficiency, and zeta is the efficiency of the auxiliary motor.

That is, in the case where the engine can generate only power without being involved in driving, the control module may calculate the power generation P0 of the engine from the power generation power of the sub-motor, the belt transmission efficiency η, and the efficiency ζ of the sub-motor, and control the engine to drive the sub-motor to generate power with the obtained power generation P0 to control the power generation power of the sub-motor.

More specifically, when the vehicle-mounted power demand is greater than the maximum allowable generated power of the sub-motor, the engine is also controlled to participate in the driving so that the engine outputs power to the wheels of the hybrid vehicle through the clutch

firstly, when the SOC value of the power battery is smaller than a preset limit value, the power battery cannot provide enough electric energy because the electric quantity of the power battery is too low, the engine and the power motor are controlled to participate in driving at the same time, the engine can be controlled to drive the auxiliary motor to generate electricity, and the engine can work in a preset optimal economic area by controlling the generated power of the engine.

Secondly, when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the depth of the accelerator pedal is larger than the first preset depth, the control module controls the engine and the power motor to participate in driving simultaneously, at the moment, the engine can be controlled to drive the auxiliary motor to generate electricity, and the engine can work in a preset optimal economic area by controlling the power generation power of the engine.

Thirdly, when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the whole vehicle resistance of the hybrid electric vehicle is larger than the first preset resistance, the control module controls the engine and the power motor to participate in driving simultaneously because the whole vehicle resistance is larger, at the moment, the engine can be controlled to drive the auxiliary motor to generate electricity, and the engine can work in a preset optimal economic area by controlling the power generation power of the engine.

Further, when the engine only drives the auxiliary motor to generate power and does not participate in driving, the generated power of the auxiliary motor can be adjusted, and the generated power control process of the embodiment of the invention is specifically described below.

According to one embodiment of the invention, the power generation of the sub motor is also controlled according to the whole vehicle required power of the hybrid vehicle, the charging power of the power battery and the charging power of the low-voltage storage battery.

Specifically, the formula for controlling the generated power of the sub motor according to the whole vehicle required power of the hybrid electric vehicle, the charging power of the power battery and the charging power of the low-voltage storage battery is as follows:

p1=p2+p3+p4, wherein p2=p11+p21,

Specifically, during the running of the hybrid electric vehicle, the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery, the entire vehicle driving power P11 and the electric equipment power P21 may be obtained, and the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery, the entire vehicle driving power P11 and the electric equipment power P21 is used as the power generation power P1 of the sub motor, so that the power generation power of the sub motor may be controlled according to the calculated P1 value, for example, the output torque and the rotation speed of the engine may be controlled according to the calculated P1 value, so as to control the power generated by the sub motor of the engine.

Further, according to an embodiment of the present invention, controlling the generated power of the sub-motor includes: and acquiring the SOC value change rate of the power battery, and controlling the power generation power of the auxiliary motor according to the relation between the required power of the whole vehicle and the minimum output power corresponding to the optimal economic area of the engine, and the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery and the SOC value change rate of the low-voltage storage battery.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power corresponding to the optimal economic region of the engine may be obtained, and after the minimum output power corresponding to the optimal economic region of the engine is determined, the power generation power of the sub-motor may be controlled according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine, and the SOC value change rate of the power battery, the SOC value of the low-voltage battery, and the SOC value change rate of the low-voltage battery.

The specific control mode of controlling the power generation power of the auxiliary motor according to the relation between the required power P2 of the whole vehicle and the minimum output power Pmin corresponding to the optimal economic area of the engine, the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery and the SOC value change rate of the low-voltage storage battery when the engine only drives the auxiliary motor to generate power and does not participate in driving is further described below.

Specifically, when the SOC value of the low-voltage storage battery is larger than a preset low-power threshold value, acquiring the charging power of the power battery according to the SOC value change rate of the power battery, and judging whether the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, wherein if the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, the power generation of the auxiliary motor is controlled by controlling the engine to generate power at the minimum output power; and if the charging power of the power battery is greater than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, acquiring the output power of the engine in the preset optimal economic area according to the sum of the charging power of the power battery and the required power of the whole vehicle, and generating power by controlling the engine to acquire the output power so as to control the power generation power of the auxiliary motor.

Specifically, when the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-power threshold value, acquiring the SOC value change rate of the low-voltage storage battery and the SOC value change rate of the power battery, acquiring the charging power of the low-voltage storage battery according to the SOC value change rate of the low-voltage storage battery, acquiring the charging power of the power battery according to the SOC value change rate of the power battery, judging whether the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, and if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the whole vehicle required power, generating electricity by controlling the engine to control the power of the auxiliary motor; and if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is greater than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, acquiring the output power of the engine in the preset optimal economic area according to the sum of the charging power of the power battery, the charging power of the low-voltage storage battery and the required power of the whole vehicle, and generating power by controlling the engine to acquire the output power so as to control the generated power of the auxiliary motor.

If the SOC value of the low-voltage storage battery is larger than a preset low-power threshold value, acquiring the SOC value change rate of the power battery, inquiring the charging power P3 of the power battery corresponding to the SOC value change rate of the power battery, selecting proper charging power P3 to enable the SOC value of the power battery to rise, further judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2, if so, that is, if P3 is smaller than Pmin-P2, generating power by controlling the engine by the minimum output power Pmin to control the power generation power of the auxiliary motor, namely controlling the engine to run at the minimum output power Pmin corresponding to the optimal economic area, and charging the power of the power battery by subtracting the power of the whole vehicle required power P2 from the minimum output power Pmin corresponding to the optimal economic area, that is Pmin-P2; if the power is not less than P3 and is more than or equal to Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, the power generation of the auxiliary motor is controlled by controlling the engine to generate power with the obtained output power, namely, the corresponding output power is searched in the preset optimal economic area of the engine, the obtained output power can be the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, namely, (P2+P3 or P11+P21+P3), and the engine is controlled to generate power with the obtained output power.

If the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-power threshold value, acquiring the SOC value change rate of the power battery, inquiring the charging power P3 of the power battery corresponding to the SOC value change rate of the power battery, selecting proper charging power P3 to enable the SOC value of the power battery to rise, acquiring the SOC value change rate of the low-voltage storage battery, inquiring the charging power P4 of the low-voltage storage battery corresponding to the SOC value change rate of the low-voltage storage battery, selecting proper charging power P4 to enable the SOC value of the low-voltage storage battery to rise, and further judging whether the sum of the charging power P4 of the low-voltage storage battery and the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2. If the power is smaller than P3+P4 and smaller than Pmin-P2, the engine is controlled to generate power at the minimum output power Pmin so as to control the power generation power of the auxiliary motor, namely the engine is controlled to run at the minimum output power Pmin corresponding to the optimal economic area, and the power of the power required by the whole vehicle P2 is subtracted from the minimum output power Pmin corresponding to the optimal economic area, namely Pmin-P2, so that the power battery and the low-voltage storage battery are charged; if the power is not less than P3+P4 is greater than or equal to Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, the power generation of the auxiliary motor is controlled by controlling the engine to generate power according to the obtained output power, namely, the corresponding output power is searched in the preset optimal economic area of the engine, and the obtained output power can be the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, namely (P2+P3+P4 or P11+P21+P3+P4), and the engine is controlled to generate power according to the obtained output power.

As described above, as shown in fig. 23, the power generation control method of the hybrid vehicle according to the embodiment of the invention includes the steps of:

s701: the SOC value M of the power battery and the vehicle speed V of the hybrid vehicle are obtained.

S702: it is determined whether the vehicle speed V of the hybrid vehicle is smaller than a first preset vehicle speed V1.

If yes, step S703 is performed; if not, step S704 is performed.

S703: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, step S707 is executed; if not, step S706 is performed.

S704: and judging whether the SOC value M of the power battery is smaller than or equal to a first preset value M1.

If yes, go to step S705; if not, step S706 is performed.

S705: the engine is controlled to participate in driving.

S706: the engine is controlled not to drive the auxiliary motor to generate power.

S707: and acquiring the depth D of an accelerator pedal of the hybrid electric vehicle and the whole vehicle resistance F of the hybrid electric vehicle.

S708: whether the depth D of the accelerator pedal is larger than a first preset depth D1 or whether the whole vehicle resistance F of the hybrid electric vehicle is larger than the first preset resistance F1 or whether the SOC value M of the power battery is smaller than a preset limit value M2 is judged.

If yes, go to step S705; if not, step S709 is performed.

S709: and acquiring the whole vehicle required power P2 of the hybrid electric vehicle.

S710: and judging whether the required power P2 of the whole vehicle is smaller than or equal to the maximum allowable power Pmax of the auxiliary motor.

If yes, step S711 is executed; if not, step S705 is performed.

S711: the engine is controlled to drive the auxiliary motor to generate power, and the engine does not participate in driving.

S712: and judging whether the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-power threshold value.

If yes, go to step S717; if not, step S713 is performed.

S713: and acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery.

S714: and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2.

If yes, go to step S715; if not, step S716 is performed.

S715: the power generation of the sub-motor is controlled by controlling the engine to generate power at the minimum output power Pmin.

S716: and obtaining the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and generating electricity by controlling the engine to obtain the output power so as to control the power generation power of the auxiliary motor.

S717: and acquiring the charging power P4 of the low-voltage storage battery according to the SOC value change rate of the low-voltage storage battery.

S718: and acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery.

S719: and judging whether the sum of the charging power P4 of the low-voltage storage battery and the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the whole vehicle required power P2.

If yes, go to step S720; if not, step S721 is performed.

S720: the power generation of the sub-motor is controlled by controlling the engine to generate power at the minimum output power Pmin.

S721: and obtaining the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, and generating electricity by controlling the engine to obtain the output power so as to control the generated power of the auxiliary motor.

In summary, according to the power generation control method of the hybrid electric vehicle provided by the embodiment of the invention, the SOC value of the power battery of the hybrid electric vehicle, the speed of the hybrid electric vehicle and the SOC value of the low-voltage storage battery of the hybrid electric vehicle are obtained, then the power generation of the auxiliary motor of the hybrid electric vehicle is controlled according to the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle, and the power generation of the engine of the hybrid electric vehicle is obtained according to the power generation of the auxiliary motor so as to control the engine to run in a preset optimal economic area, wherein the auxiliary motor is driven by the engine to generate power, so that the engine is not involved in driving at a low speed, a clutch is not used, the abrasion or sliding abrasion of the clutch is reduced, meanwhile, the pause and the comfort is improved, and the engine can be operated in the economic area only in power generation without driving, the oil consumption is reduced, the noise of the engine is maintained, the low-speed electric balance and the low-speed smoothness of the whole vehicle is maintained, and the performance of the whole vehicle is improved.

Finally, an embodiment of the present invention also proposes a computer-readable storage medium having instructions stored therein, which when executed, the hybrid vehicle performs the power generation control method of the above embodiment.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. A power system of a hybrid vehicle, comprising:

An engine that outputs power to wheels of the hybrid vehicle through a clutch;

a power motor for outputting a driving force to wheels of the hybrid vehicle;

the power battery is used for supplying power to the power motor;

a DC-DC converter;

the auxiliary motor is connected with the power motor, the DC-DC converter and the power battery respectively, and at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter is realized when the auxiliary motor generates electricity under the drive of the engine;

the control module is used for acquiring the SOC value of the power battery and the speed of the hybrid electric vehicle, and controlling the auxiliary motor to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable the engine to run in a preset optimal economic area;

the control module is also used for: acquiring the SOC value change rate of the power battery, and adjusting the power generation power P1 of the auxiliary motor according to the relation between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic area of the engine and the SOC value change rate of the power battery;

And the voltage stabilizing circuit is connected between the auxiliary motor and the DC-DC converter and is used for stabilizing the direct current output to the DC-DC converter when the auxiliary motor generates electricity.

2. The power system of a hybrid vehicle according to claim 1, wherein the sub-motor further includes a first controller, the power motor further includes a second controller, and the sub-motor is connected to the power battery and the DC-DC converter, respectively, through the first controller and the second controller, and is connected to the power motor through the first controller and the second controller.

3. The power system of a hybrid vehicle according to claim 1 or 2, wherein the DC-DC converter is further connected to the power battery.

4. The power system of a hybrid vehicle of claim 2, wherein the DC-DC converter is further coupled to the power motor via the second controller.

5. The power system of the hybrid vehicle of claim 1, wherein the DC-DC converter is further connected to a first electrical device and a low voltage battery in the hybrid vehicle, respectively, to power the first electrical device and the low voltage battery, and the low voltage battery is further connected to the first electrical device.

6. The power system of the hybrid vehicle according to claim 2, wherein the first controller, the second controller, and the power battery are further connected to a second electric device in the hybrid vehicle, respectively.

7. The power system of a hybrid vehicle of claim 1, wherein the sub-motor is a BSG motor.

8. A hybrid vehicle comprising a power system of the hybrid vehicle according to any one of claims 1-7.