CN110816249B

CN110816249B - Hybrid power driving method

Info

Publication number: CN110816249B
Application number: CN201810905245.7A
Authority: CN
Inventors: 尚阳; 赵江灵; 祁宏钟; 张安伟; 张良; 吴孝曦
Original assignee: Guangzhou Automobile Group Co Ltd
Current assignee: Guangzhou Automobile Group Co Ltd
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2020-12-29
Anticipated expiration: 2038-08-09
Also published as: CN110816249A

Abstract

A hybrid power driving method is used for controlling a hybrid power driving system to drive, the hybrid power driving system comprises an engine, a first motor, a second motor, a planetary gear device, a clutch gear device, a joint device and a switch device, wherein the engine and the first motor are connected with the planetary gear device; the planetary gear device comprises a first rotating element, a second rotating element and a third rotating element, wherein the first rotating element is connected with the first motor, the second rotating element is connected with the engine, and the third rotating element is connected with the engaging device; the clutch gear device comprises a clutch, a clutch gear connected to the clutch and an engaging element, wherein the clutch gear is connected to the output end; the engaging device engages the third rotating element with the engaging element, or engages the third rotating element with the switch device, or engages only the third rotating element; the switch device locks or unlocks the third rotating element; the second motor is connected to the output. Which can improve the overall efficiency of the hybrid drive system.

Description

Hybrid power driving method

Technical Field

The invention relates to the technical field of new energy, in particular to a hybrid power driving method.

Background

The transmissions on the market at present mainly comprise a step transmission and a continuously variable transmission. Step-variable transmissions are subdivided into manual and automatic. They most provide a limited number of discrete output-to-input speed ratios through different meshing arrangements of gear trains or planetary gear trains. The speed of the drive wheels between two adjacent speed ratios is adjusted by means of the speed variation of the internal combustion engine. Continuously variable transmissions, whether mechanical, hydraulic, or electromechanical, provide an infinite number of continuously selectable speed ratios over a range of speeds, and theoretically, the speed change of the drive wheels can be accomplished entirely through the transmission. In this way, the internal combustion engine can be operated in the optimum speed range as much as possible. Meanwhile, compared with a stepped transmission, the stepless transmission has the advantages of stable speed regulation, full utilization of the maximum power of an internal combustion engine and the like, so that the stepless transmission is a subject of research of engineers in various countries for many years.

In recent years, the emergence of motor hybrid technology has opened up a new approach for achieving complete matching of power between an internal combustion engine and a power wheel. Among the many designs of the powertrain, the most representative are the series hybrid system and the parallel hybrid system. In the motor series hybrid system, an internal combustion engine, a generator, a motor, a shafting and a driving wheel form a series power chain, and the power assembly has a very simple structure. Wherein the generator, motor combination can be considered as a transmission in the conventional sense. When used in combination with an energy storage device, such as a battery, capacitor, etc., the transmission may also function as an energy modulation device to accomplish independent speed and torque modulation.

The motor parallel system is provided with two parallel independent power chains. One is composed of a traditional mechanical speed changer, and the other is composed of a motor and a battery system. The mechanical transmission is responsible for adjusting the speed, and the motor and the battery system are responsible for adjusting the power or the torque. In order to fully develop the potential of the whole system, the mechanical transmission also needs to adopt a stepless speed change mode.

The serial hybrid system has the advantages of simple structure and flexible layout. However, all power passes through the generator and the motor, so the power requirement of the motor is high, the volume is large, and the weight is heavy. Meanwhile, the energy transmission process is electromechanical twice, and the conversion of the motor is realized, so that the efficiency of the whole system is low. In the parallel hybrid system, only part of power passes through the motor system, so the power requirement on the motor is relatively low, and the efficiency of the whole system is high. However, the system needs two sets of independent subsystems and is high in manufacturing cost. Typically only for weak mixing systems.

Disclosure of Invention

In view of the above, the present invention provides a hybrid driving method, which can improve the overall efficiency of the hybrid driving system.

A hybrid power driving method is used for controlling a hybrid power driving system to drive, the hybrid power driving system comprises an engine, a first motor, a second motor, a planetary gear device, a clutch gear device, a connecting device and a switch device, wherein the engine and the first motor are both connected with the planetary gear device, and the clutch gear device is arranged between the first motor and the planetary gear device; the planetary gear device comprises a first rotating element, a second rotating element and a third rotating element, wherein the first rotating element is connected with the first motor, the second rotating element is connected with the engine, and the third rotating element is connected with the engaging device; the clutch gear device comprises a clutch, a clutch gear connected to the clutch and an engagement element, wherein the clutch gear is connected to the output end; the engaging device engages the third rotating element with the engaging element, or engages the third rotating element with the switch device, or engages only the third rotating element; the switch device locks or unlocks the third rotating element; the second motor is arranged in parallel with the first motor, and the second motor is connected to the output end.

In an embodiment of the present invention, the engagement device includes a first operation position, a second operation position, and a third operation position, the engagement device engages and fixes the third rotating element and the engagement element in the first operation position, the engagement device engages only the third rotating element in the second operation position, and the engagement device engages and fixes the third rotating element and the switch device in the third operation position.

In an embodiment of the present invention, the first motor includes a first motor output shaft, the clutch gear device is disposed on the first motor output shaft, the clutch is connected to the first motor output shaft, the clutch gear is freely sleeved on the first motor output shaft, and the engaging element is fixed to the clutch and is parallel to the clutch gear.

In an embodiment of the present invention, the first motor, the clutch gear device, the planetary gear device, and the engine are coaxially disposed.

In an embodiment of the present invention, the first rotating element is a sun gear, the second rotating element is a carrier, the third rotating element is a ring gear, the engagement device is a synchronizer, the switching device is a brake or a one-way clutch, and the clutch gear is a first gear;

the engine is provided with an engine output shaft, the first motor is provided with a first motor output shaft, the planet carrier is connected with the engine output shaft, the sun gear is connected with the first motor output shaft, and the first gear is sleeved on the first motor output shaft in an air mode;

when the clutch works, the first gear is fixed on the output shaft of the first motor;

the brake or the one-way clutch brakes or unlocks the gear ring;

the synchronizer includes a left position, a middle position and a right position, the synchronizer is used for engaging the gear ring with the engaging element when in the left position, the synchronizer is used for braking the gear ring by the brake or the one-way clutch when in the right position, the synchronizer is used for disengaging the gear ring from the engaging element when in the middle position, and the brake or the one-way clutch unlocks the gear ring;

the hybrid power driving system further comprises an intermediate shaft, a second gear is arranged on the intermediate shaft, and the second gear is meshed with the first gear;

the second motor is provided with a second motor output shaft, a third gear is arranged on the second motor output shaft, and the third gear is meshed with the second gear.

In an embodiment of the invention, the hybrid power drive system further comprises a differential, a differential gear is arranged on the differential, a fourth gear is further arranged on the intermediate shaft, and the fourth gear is meshed with the differential gear.

In an embodiment of the present invention, the step of controlling the hybrid drive system to drive in the first stage electric-only mode comprises: the clutch does not work, the synchronizer is controlled to be arranged in an intermediate station, the engine and the first motor do not work, and the second motor is controlled to drive; the step of controlling the hybrid drive system to drive in a two-stage electric-only mode includes: and controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, controlling the synchronizer to be arranged in an intermediate station, controlling the engine not to work, and driving the first motor and the second motor.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the first-stage electric-only mode to the second-stage electric-only mode comprises:

judging whether the difference of the rotating speeds of the driving part and the driven part of the clutch is within a set value range or not; when the rotating speed difference is within a set value range, controlling the clutch to work; and when the rotating speed difference is not within the range of the set value, the first motor is used for regulating the speed, so that the rotating speed difference is within the range of the set value, and the clutch is controlled to work.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the secondary electric-only mode to the primary electric-only mode comprises:

judging whether the torque of the first motor is within a set value range or not; when the torque is in a set value range, controlling the clutch to be out of work; and when the torque is not in the set value range, controlling the second motor and the first motor to perform torque coordination control, and when the torque reaches the set value range, controlling the clutch to be out of operation.

In an embodiment of the present invention, the step of controlling the hybrid drive system to drive in the range-extended mode includes: and controlling the synchronizer to be arranged at a right station, braking the gear ring by the brake or the one-way clutch, controlling the engine to drive the first motor to generate power, providing electric energy for the second motor by the first motor, and driving the second motor.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the first-stage electric-only mode to the range-extended mode includes:

judging the rotation speed difference between the brake or the one-way clutch and the gear ring, and controlling the first motor to regulate the speed when the rotation speed difference is greater than or equal to a set value; and when the rotating speed difference is smaller than a set value, judging a torque value of the gear ring, when the torque value is larger than or equal to the set value, controlling the first motor to perform torque coordination control, and when the torque value is smaller than the set value, controlling the synchronizer to be arranged at a right station to control the engine to start.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the range-extended mode to the first electric-only mode comprises:

controlling the engine not to work, and judging whether the rotating speed of the engine is in a range of a set value or not; and when the rotating speed is within the range of the set value, controlling the synchronizer to be arranged in an intermediate station.

In an embodiment of the present invention, the step of controlling the hybrid drive system to drive in the primary engine direct drive mode includes: controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, the synchronizer to be placed at a left station is controlled, the gear ring is connected with the connecting element, the engine is controlled to drive, and the first motor and the second motor do not work; the step of controlling the hybrid power driving system to drive in the secondary engine direct drive mode comprises the following steps: and controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, controlling the synchronizer to be arranged at a right station, braking the gear ring by the brake or the one-way clutch, controlling the engine to drive, and preventing the first motor and the second motor from working.

In an embodiment of the invention, the step of controlling the hybrid drive system to switch from the range extended mode to the secondary engine direct drive mode comprises:

judging whether the difference of the rotating speeds of the driving part and the driven part of the clutch is within a set value range or not; when the rotating speed difference is within a set value range, controlling the clutch to work; and when the rotating speed difference is not within the range of the set value, controlling the first motor to regulate the speed, so that the rotating speed difference reaches the range of the set value, and controlling the clutch to work.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the secondary engine direct drive mode to the range extended mode comprises:

the method comprises the following steps of performing friction sliding control in a rotating speed difference range of a driving part and a driven part of the clutch, performing torque coordination control on the engine by utilizing the second motor, and judging whether the rotating speed difference of the driving part and the driven part of the clutch is in a set value range or not; and when the rotating speed difference is within the set value range, controlling the clutch to be out of operation.

In an embodiment of the present invention, the step of controlling the hybrid drive system to drive in the one-stage hybrid mode includes: controlling the clutch to be out of work, controlling the synchronizer to be arranged at a left station, controlling the gear ring to be connected with the connecting element, controlling the engine to drive the planet carrier to rotate, controlling the first motor to drive the sun gear to rotate, and controlling the engine and the first motor to be in stepless coupling through the planetary gear device to control the second motor to drive; the step of controlling the hybrid drive system to drive in the two-stage hybrid mode comprises: controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, the synchronizer to be placed at a left station is controlled, the gear ring is engaged with the engaging element, and the engine, the first motor and the second motor are controlled to be driven; the step of controlling the hybrid drive system to drive in a three-stage hybrid mode includes: and controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, controlling the synchronizer to be arranged at a right station, braking the gear ring by the brake or the one-way synchronizer, and controlling the engine, the first motor and the second motor to drive.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the one-stage electric-only mode to the one-stage hybrid mode includes:

judging the rotation speed difference between the synchronizer and the first gear, and controlling the first motor to regulate the speed when the rotation speed difference is greater than or equal to a set value; when the rotating speed difference is smaller than a set value, the torque value of the gear ring is judged, when the torque value is larger than or equal to the set value, the first motor is controlled to carry out torque coordination control, and when the torque value is smaller than the set value, the synchronizer is controlled to be arranged at a left station to control the engine to start.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the one-stage hybrid mode to the one-stage electric-only mode comprises:

judging the vehicle speed, performing fuel cut-off control on the engine when the vehicle speed is greater than or equal to a set value, performing torque coordination control by using the first motor, placing the synchronizer in a middle station, and then controlling the engine to stop working; and when the vehicle speed is less than a set value, controlling the engine not to work, and placing the synchronizer in a middle station.

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the first-stage hybrid mode to the first-stage engine direct drive mode comprises:

In an embodiment of the present invention, the step of controlling the hybrid drive system to switch from the primary engine direct drive mode to the primary hybrid mode comprises:

and controlling the clutch to be out of operation, carrying out torque coordination control on the first motor, calculating the engine torque instruction, the first motor torque instruction and the second motor torque instruction, and sending the instructions.

The hybrid power driving method is used for controlling a hybrid power driving system to drive, an engine and a first motor of the hybrid power driving system are both connected with a planetary gear device, and a clutch gear device is arranged between the first motor and the planetary gear device; the planetary gear device comprises a first rotating element, a second rotating element and a third rotating element, wherein the first rotating element is connected with the first motor, the second rotating element is connected with the engine, and the third rotating element is connected with the engaging device; the clutch gear device comprises a clutch, a clutch gear connected to the clutch and an engagement element, wherein the clutch gear is connected to the output end; the engaging device engages the third rotating element with the engaging element, or engages the third rotating element with the switch device, or engages only the third rotating element; the switch device locks or unlocks the third rotating element; the second motor is arranged in parallel with the first motor, and the second motor is connected to the output end. The hybrid power driving method can control the hybrid power driving system to drive in each mode, and can ensure that each mode can be freely switched, so that the performance of the hybrid power driving system is optimal, the overall efficiency of the hybrid power driving system is improved, and the power requirements of the system on the first motor and the motor are reduced.

Drawings

Fig. 1 is a schematic configuration diagram of a hybrid drive system of a first embodiment of the invention.

Fig. 2 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the one-stage electric-only mode.

FIG. 3 is a power transmission schematic diagram of the hybrid drive system of the first embodiment of the present invention in the two-stage electric-only mode.

Fig. 4 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the range extending mode.

FIG. 5 is a power transmission schematic diagram of the hybrid drive system of the first embodiment of the present invention in the first stage engine direct drive mode.

FIG. 6 is a power transmission schematic diagram of the hybrid drive system of the first embodiment of the present invention in the two-stage engine direct drive mode.

Fig. 7 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the one-stage hybrid mode.

Fig. 8 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the two-stage hybrid mode.

Fig. 9 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the three-stage hybrid mode.

Fig. 10 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the parking power generation mode.

Fig. 11 is a schematic configuration diagram of a hybrid drive system of a second embodiment of the invention.

Fig. 12 is a graph of wheel end torque versus vehicle speed in each drive mode of the hybrid drive system of the present invention.

FIG. 13a is a flow chart illustrating a hybrid drive system switching from a first-level electric-only mode to a second-level electric-only mode.

FIG. 13b is a flow chart illustrating a process for controlling the hybrid drive system to switch from the first-stage electric-only mode to the second-stage electric-only mode.

FIG. 14a is a flow chart illustrating a process for controlling the hybrid drive system to switch from the first-stage electric-only mode to the range-extended mode.

FIG. 14b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the range extended mode to the first electric-only mode.

FIG. 15a is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the range extended mode to the two-stage engine direct drive mode.

FIG. 15b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the two-stage engine direct drive mode to the range extended mode.

FIG. 16a is a flow chart illustrating a process for controlling the hybrid drive system to switch from the one-stage electric-only mode to the one-stage hybrid mode.

FIG. 16b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the one-stage hybrid mode to the one-stage electric-only mode.

FIG. 17a is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the one-stage hybrid mode to the one-stage engine direct drive mode.

FIG. 17b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the first stage engine direct drive mode to the first stage hybrid mode.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.

First embodiment

Fig. 1 is a schematic configuration diagram of a hybrid drive system of a first embodiment of the invention. As shown in fig. 1, the hybrid drive system 10 includes an engine 11, a planetary gear device 12, a first electric machine 13, a clutch gear device, a switching device, an engagement device, an intermediate shaft 17, a second electric machine 18, a differential 19, and a power battery (not shown).

The engine 11 has an engine output shaft 112. In the present embodiment, the engine 11 is, for example, a gasoline engine or a diesel engine.

The planetary gear device 12 includes a first rotating element, a second rotating element, and a third rotating element. The first rotational element is connected to the first electric machine 13, the second rotational element is connected to the engine 11, and the third rotational element is connected to the engagement device. In the present embodiment, the first rotating element 122 is, for example, a sun gear 122, the second rotating element is, for example, a planet carrier 124, and the third rotating element is, for example, a ring gear 123. The planet carrier 124 is provided with planet wheels 125, and the planet wheels 125 are connected to the planet carrier 124 through rolling or sliding bearings; the carrier 124 is connected to the engine output shaft 112. The sun gear 122 is disposed within the ring gear 123, and the sun gear 122 is meshed with the planet gears 125 and the ring gear 123, respectively.

The first motor 13 has a first motor output shaft 132, the first motor output shaft 132 is connected to the sun gear 122, and a first gear 133 is sleeved on the first motor output shaft 132. The first gear 133 is freely sleeved on the first motor output shaft 132, i.e. the first motor output shaft 132 and the first gear 133 are not affected by each other when rotating respectively. The first motor 13 is disposed coaxially with the engine 11, i.e., the first motor output shaft 132 of the first motor 13 is coaxial with the engine output shaft 112 of the engine 11. In the present embodiment, the first motor 13 is a driving and power generating integrated machine.

The clutch gear device is provided coaxially with the first motor 13, the planetary gear device 12, and the engine 11. The clutch gear device includes a clutch 14, and a clutch gear connected to the output end and the engaging element connected to the clutch 14. The clutch gear device is arranged on the first motor output shaft 132, the clutch 14 is connected with the first motor output shaft 132, the clutch gear is sleeved on the first motor output shaft 132 in a hollow mode, the engaging element is fixed on the clutch 14 and is parallel to the clutch gear, and the clutch gear and the engaging element can rotate synchronously. In the present embodiment, the clutch gear is, for example, the first gear 133. When the clutch 14 is in operation, the clutch 14 fixes the first gear 133 (clutch gear) on the first motor output shaft 132, the first gear 133 can rotate synchronously with the first motor output shaft 132, and when the clutch 14 is not in operation, the first gear 133 (clutch gear) is freely sleeved on the first motor output shaft 132.

The switch device is used to lock or unlock the ring gear 123 (third rotating element). In the present embodiment, the switching device is, for example, a brake 15 or a one-way clutch. The brake 15 is used to brake or unlock the ring gear 123. When the brake 15 is operated, the brake 15 brakes the ring gear 123; when the brake 15 is not operated, the brake 15 unlocks the ring gear 123.

The engagement means engages the third rotational element with the engagement element, or engages the third rotational element with the switch means, or engages only the third rotational element. In particular, the engagement means comprise a first operating position, in which they engage and fix the third rotary element with the engagement element, a second operating position, in which they engage only the third rotary element, and a third operating position, in which they engage and fix the third rotary element with the switching device. In the present embodiment, the engaging device is, for example, a synchronizer 16, and the synchronizer 16 includes a left station, a middle station and a right station, wherein the left station is a first working position of the engaging device, the middle station is a second working position of the engaging device, and the right station is a third working position of the engaging device. The synchronizer 16 is fixed to the ring gear 123, and the ring gear 123 is engaged with the engaging element when the synchronizer 16 is in the left station; when the synchronizer 16 is at the right station, the brake 15 brakes the gear ring 123; in the neutral position of the synchronizer 16, the ring gear 123 is disengaged from the engaging elements, and the brake 15 or the one-way clutch unlocks the ring gear 123.

The intermediate shaft 17 is provided with a second gear 172 and a fourth gear 173, the second gear 172 and the fourth gear 173 are arranged at intervals, and the second gear 172 is meshed with the first gear 133.

The second motor 18 is arranged in parallel with the first motor 13, and the second motor 18 is connected to the output terminal. Specifically, the second motor 18 has a second motor output shaft 182, a third gear 183 is disposed on the second motor output shaft 182, and the third gear 183 is engaged with the second gear 172. In this embodiment, the second motor 18 is an integrated drive and generator.

A differential gear 192 is provided on the differential 19, and the differential gear 192 and the fourth gear 173 are meshed with each other. In this embodiment, the differential 19 is used to adjust the difference between the rotation speeds of the left and right wheels, so that the left and right wheels roll at different rotation speeds when the vehicle is turning or running on an uneven road surface, thereby ensuring that the wheels are driven by both sides to perform pure rolling motion.

The power battery is electrically connected with the first motor 13 and the second motor 18 respectively. The power battery supplies electric power for driving the first motor 13 and the second motor 18, and electric power generated by rotation of the first motor 13 and the second motor 18 may be stored in the power battery. In the present embodiment, the engine 11 drives the first electric machine 13 to rotate through the planet carrier 124 and the sun gear 122 to generate electric energy, and the electric energy can be stored in the power battery; when the automobile brakes, power is transmitted from the wheel end to the second electric machine 18 through the differential 19, the differential gear 192, the fourth gear 173, the second gear 172 and the third gear 183, and the second electric machine 18 is driven to rotate to generate electric energy, and the electric energy can be stored in a power battery.

The hybrid drive system 10 of the present invention has a primary electric only mode, a secondary electric only mode, a range extended mode, a primary engine direct drive mode, a secondary engine direct drive mode, a primary hybrid mode, a secondary hybrid mode, a tertiary hybrid mode, and a parking power generation mode.

Fig. 2 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the one-stage electric-only mode. As shown in fig. 2, the power transmission direction is as indicated by the arrow in the figure, and in the one-stage electric-only mode, the clutch 14 is not operated, the synchronizer 16 is in the middle position, the engine 11 and the first motor 13 are not operated, and the second motor 18 is driven. In this embodiment, the power transmission has a path from the second motor 18 through the third gear 183 to the second gear 172, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It is worth mentioning that the hybrid drive system 10 can be driven in a first-order electric-only mode when the vehicle is running at a medium-low speed.

FIG. 3 is a power transmission schematic diagram of the hybrid drive system of the first embodiment of the present invention in the two-stage electric-only mode. As shown in fig. 3, the power transmission direction is as indicated by the arrow in the figure, and in the two-stage electric only mode, the clutch 14 is operated, the clutch 14 fixes the first gear 133 to the first motor output shaft 132, the synchronizer 16 is in the intermediate position, and both the first motor 13 and the second motor 18 are driven. In the present embodiment, the power transmission has two paths, wherein the first path is transmitted from the first motor 13 to the intermediate shaft 17 through the first gear 133, then to the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end; path two is transmitted by the second motor 18 through the third gear 183 to the second gear 172, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It is worth mentioning that the hybrid drive system 10 can be driven in the two-stage electric-only mode when the vehicle is traveling at high speeds.

Fig. 4 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the range extending mode. As shown in fig. 4, the power transmission direction is as shown by the arrow direction in the figure, in the range extending mode, the synchronizer 16 is at the right position, the brake 15 or the one-way clutch brakes the gear ring 123, the engine 11 drives the first motor 13 to generate power, the first motor 13 provides power for the second motor 18, and the second motor 18 drives. The engine 11 drives the planetary carrier 124 to transmit power to the sun gear 122 and then to the first motor 13, so that the first motor 13 rotates to generate power, and the electric energy generated by the first motor 13 is stored in the power battery and is provided for driving the second motor 18 by the power battery. In this embodiment, the power transmission has a path from the second motor 18 through the third gear 183 to the second gear 172, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end.

FIG. 5 is a power transmission schematic diagram of the hybrid drive system of the first embodiment of the present invention in the first stage engine direct drive mode. As shown in fig. 5, the power transmission direction is as indicated by the arrow in the drawing, in the one-stage engine direct drive mode, the clutch 14 is operated, the clutch 14 fixes the first gear 133 to the first motor output shaft 132, the synchronizer 16 is in the left position, the ring gear 123 is engaged with the engaging element, the engine 11 is driven, and neither the first motor 13 nor the second motor 18 is operated. In the present embodiment, the power transmission has a path, the engine 11 drives the entire planetary row 12 to rotate, the speed ratio of the entire planetary row 12 is 1, the rotation speeds of the sun gear 122, the planet carrier 124 and the ring gear 123 are the same, and the power is transmitted from the first gear 133 to the intermediate shaft 17, then to the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It is worth mentioning that the hybrid drive system 10 can be driven in the first-stage engine direct drive mode when the vehicle is running at a medium-low speed.

FIG. 6 is a power transmission schematic diagram of the hybrid drive system of the first embodiment of the present invention in the two-stage engine direct drive mode. As shown in fig. 6, the power transmission direction is as shown by the arrow direction in the figure, in the two-stage engine direct drive mode, the clutch 14 operates, the clutch 14 fixes the first gear 133 on the first motor output shaft 132, the synchronizer 16 is in the right position, the brake 15 or the one-way clutch brakes the ring gear 123, the engine 11 is driven, and neither the first motor 13 nor the second motor 18 operates. In this embodiment, the power transmission has a path, and the engine 11 drives the planet carrier 124 to transmit power to the sun gear 122, the first gear 133 to the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It is worth mentioning that the hybrid drive system 10 can be driven in the secondary engine direct drive mode when the vehicle is traveling at medium to high speeds.

Fig. 7 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the one-stage hybrid mode. As shown in fig. 7, the power transmission direction is as indicated by the arrow in the figure, in the one-stage hybrid mode, the clutch 14 is not operated, the synchronizer 16 is in the left position, the ring gear 123 is engaged with the engagement element, the engine 11 drives the carrier 124 to rotate, the first motor 13 drives the sun gear 122 to rotate, the engine 11 and the first motor 13 are steplessly coupled through the planetary gear device 12, and the second motor 18 is driven. In the embodiment, the power transmission has two paths, wherein in the first path, the power of the engine 11 is transmitted through the planet carrier 124, the power of the first motor 13 is transmitted through the sun gear 122, the power of the engine 11 and the first motor 13 is steplessly coupled through the planet row 12, is output through the ring gear 123, is transmitted to the first gear 133 and the intermediate shaft 17, is transmitted to the fourth gear 173, the differential gear 192 and the differential 19, and finally reaches the wheel end; path two is transmitted by the second motor 18 through the third gear 183 to the second gear 172, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It should be noted that when the hybrid drive system 10 is driven in the first-order hybrid mode, the system is in an ecvt (electronic controlled variable transmission) stepless speed regulation mode, the operating point of the engine 11 can be adjusted by the first electric machine 13 and the second electric machine 18, and is decoupled from the wheel-end output torque, so that the engine 11 is always operated in a high-efficiency region, and the system can ensure the dynamic property and the economical efficiency, so that the system can be developed for medium-high-class vehicles. The hybrid drive system 10 may be driven in a first engine direct drive mode when the vehicle is running at full speed.

Fig. 8 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the two-stage hybrid mode. As shown in fig. 8, the power transmission direction is as indicated by the arrow in the drawing, and in the two-stage hybrid mode, the clutch 14 is operated, the clutch 14 fixes the first gear 133 to the first motor output shaft 132, the synchronizer 16 is in the left position, the ring gear 123 is engaged with the engaging element, and the engine 11, the first motor 13, and the second motor 18 are all driven. In the embodiment, the power transmission has two paths, wherein in the first path, the power of the engine 11 is transmitted through the planet carrier 124, the first motor 13 is transmitted through the sun gear 122, at this time, the rotation speeds of the sun gear 122, the planet carrier 124 and the ring gear 123 of the planetary row 12 are the same, the speed ratio of the whole planetary gear device 12 is 1, the power is transmitted from the first gear 133, the intermediate shaft 17, the fourth gear 173, the differential gear 192 and the differential 19, and finally to the wheel end; path two is transmitted by the second motor 18 through the third gear 183 to the second gear 172, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It is worth mentioning that the hybrid drive system 10 can be driven in the secondary engine direct drive mode when the vehicle is running at medium or low speed.

Fig. 9 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the three-stage hybrid mode. As shown in fig. 9, the power transmission direction is as indicated by the arrow in the drawing, and in the three-stage hybrid mode, the clutch 14 is operated, the clutch 14 fixes the first gear 133 to the first motor output shaft 132, the synchronizer 16 is in the right position, the brake 15 or the one-way clutch brakes the ring gear 123, and the engine 11, the first motor 13, and the second motor 18 are driven. In the embodiment, the power transmission has two paths, wherein in the first path, the engine 11 drives the planet carrier 124 to transmit power to the sun gear 122, the first motor 13 also transmits power to the sun gear 122, and after coupling, the power is transmitted to the wheel end through the first gear 133, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19 and the like; path two is transmitted by the second motor 18 through the third gear 183 to the second gear 172, the intermediate shaft 17, the fourth gear 173, the differential gear 192, the differential 19, and finally to the wheel end. It is worth mentioning that the hybrid drive system 10 can be driven in a three-stage hybrid mode when the vehicle is traveling at medium to high speeds.

Fig. 10 is a power transmission diagram of the hybrid drive system of the first embodiment of the invention in the parking power generation mode. As shown in fig. 10, the power transmission direction is as indicated by the arrow in the drawing, and in the parking power generation mode, the clutch 14 is not operated, the synchronizer 16 is in the intermediate position, the engine 11 and the first motor 13 are not operated, and the second motor 18 generates power. In the embodiment, the power transmission has a path, and the power is transmitted to the second electric machine 18 from the wheel end through the differential 19, the differential gear 192, the fourth gear 173, the second gear 172 and the third gear 183, so as to drive the second electric machine 18 to rotate to generate electric energy.

The hybrid power driving system 10 of the invention has a primary pure electric mode, a secondary pure electric mode, a range extending mode, a primary engine direct driving mode, a secondary engine direct driving mode, a primary hybrid mode, a secondary hybrid mode, a tertiary hybrid mode and a parking power generation mode, and can automatically realize the switching of different modes according to the SOC (residual electric quantity) value of a power battery and the vehicle speed requirement. For example, judging the magnitude relation between the SOC value of the power battery and a first threshold value, or simultaneously judging the magnitude relation between the SOC value of the power battery and the first threshold value and the magnitude relation between the vehicle speed and a second threshold value; the operation mode of the hybrid drive system 10 is switched according to the determination result. It should be noted that the first threshold is used to determine the SOC value of the power battery, and the second threshold is used to determine the vehicle speed, and the embodiment does not limit the value ranges of the first threshold and the second threshold, and may be freely set according to a specific control strategy, and the values of the first threshold and the second threshold are different under different control strategies. After the first threshold value and the second threshold value are set, automatic judgment is carried out, and automatic switching is carried out among various modes according to the judgment result.

The nine modes are embodied as the following table:

second embodiment

Fig. 11 is a schematic configuration diagram of a hybrid drive system of a second embodiment of the invention. As shown in fig. 11, the hybrid drive system 10 of the present embodiment is substantially the same in structure as the hybrid drive system 10 of the first embodiment, and differs in the connection relationship between the engine 11 and the planetary gear device 12 and the connection relationship between the engagement device and the planetary gear device 12.

Specifically, in the present embodiment, the first rotating element is a sun gear, the second rotating element is a ring gear, the third rotating element is a planet carrier, the engaging device is a synchronizer, the switching device is a brake or a one-way clutch, that is, the ring gear 123 is connected with the engine output shaft 112, the synchronizer 16 is fixed on the planet carrier 124, and the synchronizer 16 includes a left position, a middle position, and a right position; with the synchronizer 16 in the left position, the planet carrier 124 is engaged with the engagement element; when the synchronizer 16 is in the right work position, the brake 15 or the one-way clutch brakes the planet carrier 124; in the neutral position of the synchronizer 16, the carrier 124 is disengaged from the engagement elements, and the brake 15 or the one-way clutch unlocks the carrier 124. For the connection relationship and the driving method of the components of the hybrid drive system 10, refer to the first embodiment.

The hybrid drive system 10 of the present embodiment has a first-stage pure electric mode, a second-stage pure electric mode, a range extending mode, a first-stage engine direct drive mode, a second-stage engine direct drive mode, a first-stage hybrid mode, a second-stage hybrid mode, a third-stage hybrid mode, and a parking power generation mode, and for the working state of the hybrid drive system 10 in each mode, reference is made to the first embodiment, and details are not repeated here.

Third embodiment

The hybrid drive system 10 of the present embodiment is substantially identical in structure to the hybrid drive system 10 of the first embodiment, and is different in the connection relationship between the engine 11 and the planetary gear device 12 and the connection relationship between the engagement device and the planetary gear device 12.

Specifically, the first rotating element is a planet carrier, the second rotating element is one of a sun gear and a ring gear, the third rotating element is the other of the sun gear and the ring gear, the engaging device is a synchronizer, and the switching device is a brake or a one-way clutch. For the connection relationship and the driving method of the components of the hybrid drive system 10, refer to the first embodiment.

Fourth embodiment

Specifically, the first rotating element is a ring gear, the second rotating element is one of a sun gear and a planet carrier, the third rotating element is the other of the sun gear and the planet carrier, the engagement device is a synchronizer, and the switching device is a brake or a one-way clutch. For the connection relationship and the driving method of the components of the hybrid drive system 10, refer to the first embodiment.

Fifth embodiment

Fig. 12 is a graph of wheel end torque versus vehicle speed in each drive mode of the hybrid drive system of the present invention. Referring to fig. 2 to 12, the present invention further relates to a hybrid driving method for controlling the hybrid driving system 10 to drive. In the embodiment, the hybrid driving method of the present invention can not only control the hybrid driving system 10 to be driven in the primary pure electric mode, the secondary pure electric mode, the range-extended mode, the primary engine direct-drive mode, the secondary engine direct-drive mode, the primary hybrid mode, the secondary hybrid mode, and the tertiary hybrid mode, but also control the hybrid driving system 10 to be switched between the modes, such as switching from the primary pure electric mode to the secondary pure electric mode, switching from the primary pure electric mode to the range-extended mode, switching from the range-extended mode to the primary pure electric mode, switching from the primary engine direct-drive mode to the secondary engine direct-drive mode, switching from the secondary engine direct-drive mode to the primary engine mode, switching from the range-extended mode to the secondary engine direct-drive mode, and controlling the hybrid driving, The range extending method includes switching from a secondary engine direct-drive mode to a range extending mode, switching from a primary pure electric mode to a primary hybrid mode, switching from a primary hybrid mode to a primary pure electric mode, switching from a primary hybrid mode to a primary engine direct-drive mode, switching from a primary engine direct-drive mode to a primary hybrid mode, switching from a range extending mode to a primary hybrid mode, and switching from a primary hybrid mode to a range extending mode, but is not limited thereto.

Specifically, in the present embodiment, the step of controlling the hybrid drive system 10 to drive in the one-stage electric-only mode includes: the control clutch 14 and the control synchronizer 16 are arranged in the middle position, the engine 11 and the first motor 13 do not work, and the second motor 18 drives.

The step of controlling the hybrid drive system 10 to drive in the two-stage electric-only mode includes: the clutch 14 is controlled to work, the clutch 14 enables the first gear 133 to be fixed on the first motor output shaft 132, the synchronizer 16 is controlled to be placed in the middle position, the engine 11 does not work, and the first motor 13 and the second motor 18 are driven.

It is worth mentioning that when the clutch 14 is in operation, the driving part and the driven part of the clutch 14 are coupled together; when the clutch 14 is not operating, the driving and driven portions of the clutch 14 are disconnected from each other as shown in the above table.

FIG. 13a is a flow chart illustrating a hybrid drive system switching from a first-level electric-only mode to a second-level electric-only mode. As shown in fig. 12 and 13a, the step of controlling the hybrid drive system 10 to switch from the first-stage electric-only mode to the second-stage electric-only mode includes:

determining whether the difference in the rotational speeds of the driving portion and the driven portion of the clutch 14 is within a set value range; when the rotational speed difference is within the set value range, controlling the clutch 14 to work; when the rotation speed difference is not within the set value range, the first motor 13 is used for speed regulation to enable the rotation speed difference to reach the set value range, and then the clutch 14 is controlled to work.

FIG. 13b is a flow chart illustrating a process for controlling the hybrid drive system to switch from the first-stage electric-only mode to the second-stage electric-only mode. As shown in fig. 12 and 13b, the step of controlling the hybrid drive system 10 to switch from the second-stage electric-only mode to the first-stage electric-only mode includes:

judging whether the torque of the first motor 13 is within a set value range; when the torque is in the set value range, the clutch 14 is controlled not to work; when the torque is not in the set value range, the second motor 18 and the first motor 13 are controlled to perform torque coordination control, and when the torque reaches the set value range, the clutch 14 is controlled not to work.

In the present embodiment, the step of controlling the hybrid drive system 10 to be driven in the range-extended mode includes: the synchronizer 16 is controlled to be arranged at a right station, the brake 15 or the one-way clutch brakes the gear ring 123, the engine 11 is controlled to drive the first motor 13 to generate power, the first motor 13 provides electric energy for the second motor 18, and the second motor 18 drives.

FIG. 14a is a flow chart illustrating a process for controlling the hybrid drive system to switch from the first-stage electric-only mode to the range-extended mode. As shown in fig. 12 and 14a, the step of controlling the hybrid drive system 10 to switch from the first-stage electric-only mode to the range-extended mode includes:

judging the rotation speed difference between the brake 15 or the one-way clutch and the gear ring 123, and controlling the first motor 13 to regulate the speed when the rotation speed difference is greater than or equal to a set value; when the rotation speed difference is smaller than a set value, the torque value of the gear ring 123 is judged, when the torque value is larger than or equal to the set value, the first motor 13 is controlled to perform torque coordination control, and when the torque value is smaller than the set value, the synchronizer 16 is controlled to be arranged at the right station, and the engine 11 is controlled to start.

FIG. 14b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the range extended mode to the first electric-only mode. As shown in fig. 12 and 14b, the step of controlling the hybrid drive system 10 to switch from the range extended mode to the primary electric-only mode includes:

controlling the engine 11 not to work, and judging whether the rotating speed of the engine 11 is in the range of a set value or not; when the rotational speed is within the set value range (for example, when the rotational speed of the engine 11 is 0), the control synchronizer 16 is placed in the intermediate position.

In the present embodiment, the step of controlling the hybrid drive system 10 to drive in the first-stage engine direct drive mode includes: the clutch 14 is controlled to work, the clutch 14 enables the first gear 133 to be fixed on the first motor output shaft 132, the synchronizer 16 is controlled to be placed at the left station, the gear ring 123 is connected with the connecting element to control the engine 11 to drive, and the first motor 13 and the second motor 18 do not work.

The steps of controlling the hybrid drive system 10 to drive in the secondary engine direct drive mode include: controlling the clutch 14 to work, wherein the clutch 14 enables the first gear 133 to be fixed on the first motor output shaft 132, controlling the synchronizer 16 to be placed at the right station, controlling the brake 15 or the one-way clutch to brake the gear ring 123, controlling the engine 11 to drive, and controlling the first motor and the second motor 13 and the second motor 18 not to work.

FIG. 15a is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the range extended mode to the two-stage engine direct drive mode. As shown in fig. 12 and 15a, the step of controlling the hybrid drive system 10 to switch from the range extended mode to the two-stage engine direct drive mode includes:

determining whether the difference in the rotational speeds of the driving portion and the driven portion of the clutch 14 is within a set value range; when the rotational speed difference is within the set value range, controlling the clutch 14 to work; when the rotation speed difference is not within the set value range, the first motor 13 is controlled to regulate the speed, so that the rotation speed difference is within the set value range, and the clutch 14 is controlled to work.

FIG. 15b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the two-stage engine direct drive mode to the range extended mode. As shown in fig. 12 and 15b, the step of controlling the hybrid drive system 10 to switch from the two-stage engine direct drive mode to the range extended mode includes:

slip control in a range of a difference in rotation speed between the driving portion and the driven portion of the clutch 14, and torque coordination control of the engine 11 by the second electric machine 18, and whether or not the difference in rotation speed between the driving portion and the driven portion of the clutch 14 is within a set value range; when the rotational speed difference is within the set value range, the control clutch 14 is not operated.

In the present embodiment, the step of controlling the hybrid drive system 10 to be driven in the one-stage hybrid mode includes: the control clutch 14 is not operated, the synchronizer 16 is controlled to be arranged at a left working position, the gear ring 123 is connected with the connecting element, the engine 11 is controlled to drive the planet carrier 124 to rotate, the first motor 13 is controlled to drive the sun gear 122 to rotate, the engine 11 and the first motor 13 are in stepless coupling through the planetary gear device 12, and the second motor 18 is controlled to drive.

The step of controlling the hybrid drive system 10 to drive in the two-stage hybrid mode includes: the clutch 14 is controlled to work, the clutch 14 enables the first gear 133 to be fixed on the first motor output shaft 132, the synchronizer 16 is controlled to be placed in the left station, the gear ring 123 is connected with the connecting element, and the engine 11, the first motor 13 and the second motor 18 are controlled to be driven.

The step of controlling the hybrid drive system 10 to drive in the three-stage hybrid mode includes: the clutch 14 is controlled to work, the clutch 14 enables the first gear 133 to be fixed on the first motor output shaft 132, the synchronizer 16 is controlled to be placed at the right position, the brake 15 or the one-way synchronizer brakes the gear ring 123, and the engine 11, the first motor 14 and the second motor 18 are controlled to be driven.

FIG. 16a is a flow chart illustrating a process for controlling the hybrid drive system to switch from the one-stage electric-only mode to the one-stage hybrid mode. As shown in fig. 12 and 16a, the step of controlling the hybrid drive system 10 to switch from the one-stage electric-only mode to the one-stage hybrid mode includes:

judging the difference between the rotation speeds of the synchronizer 16 and the first gear 133, and controlling the first motor 13 to regulate the speed when the difference is greater than or equal to a set value; when the difference of the rotational speeds is smaller than a set value, the torque value of the gear ring 123 is judged, when the torque value is larger than or equal to the set value, the first motor 13 is controlled to perform torque coordination control, and when the torque value is smaller than the set value, the synchronizer 16 is controlled to be arranged at a left station, and the engine 11 is controlled to start.

FIG. 16b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the one-stage hybrid mode to the one-stage electric-only mode. As shown in fig. 12 and 16b, the step of controlling the hybrid drive system 10 to switch from the one-stage hybrid mode to the one-stage electric-only mode includes:

judging the vehicle speed, performing fuel cut-off control on the engine 11 when the vehicle speed is greater than or equal to a set value, performing torque coordination control by using the first motor 13, placing the synchronizer 16 in a middle station, and then controlling the engine 11 not to work; when the vehicle speed is less than the set value, the engine 11 is controlled not to work, and the synchronizer 16 is placed in the middle station.

FIG. 17a is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the one-stage hybrid mode to the one-stage engine direct drive mode. As shown in fig. 12 and 17a, the step of controlling the hybrid drive system 10 to switch from the first-stage hybrid mode to the first-stage engine direct drive mode includes:

FIG. 17b is a schematic flow chart illustrating the process for controlling the hybrid drive system to switch from the first stage engine direct drive mode to the first stage hybrid mode. As shown in fig. 12 and 17b, the step of controlling the hybrid drive system 10 to switch from the primary engine direct drive mode to the primary hybrid mode includes:

the control clutch 14 is not operated, and the torque coordination control is performed on the first motor 13, and the engine 11 torque command, the first motor 13 torque command, and the second motor 18 torque command are calculated and transmitted. In this embodiment, the specific steps of switching the first-stage engine direct drive mode to the first-stage hybrid mode include:

controlling the clutch 14 not to work, obtaining the torque Tr required by the wheel end according to the opening of an accelerator pedal and vehicle speed interpolation (interpolation function), and obtaining driving required power, battery power and system loss power according to the opening of the accelerator pedal, the vehicle speed and SOC interpolation, so as to obtain system required power Pr; when the system demand efficiency is smaller than a set value, a first-stage pure electric mode is entered, and when the system demand efficiency is larger than the set value, a target rotating speed and torque of the engine 11 are obtained through interpolation according to the system demand efficiency and the optimal working curve of the engine 11. Calculating a target rotation speed Nm1 of the first motor 13 according to the vehicle speed and the target rotation speed of the engine 11, and controlling the first motor 13 to reach the target rotation speed through PID; then, the limit (maximum output torque) of the output torque of the second motor 18 is calculated according to the charge and discharge power of the power battery, a positive torque-Tm 1 xK is transmitted to the gear ring 123 by the engine 11 according to the torque characteristic of the planet wheel 125, and the torque of the second motor 18 is equal to the torque required by the wheel end minus the positive torque transmitted to the gear ring 123 by the engine 11; but this torque must be within the limits of the output torque of the second electric machine 18; and sending the torque commands of the engine 11, the second motor 18 and the first motor 13 to enter a first-stage hybrid mode.

The hybrid power driving method is used for controlling the hybrid power driving system 10 to drive, an engine 11 and a first motor 13 of the hybrid power driving system 10 are both connected with a planetary gear device 12, and a clutch gear device is arranged between the first motor 13 and the planetary gear device 12; the planetary gear device 12 includes a first rotating element connected with the first motor 13, a second rotating element connected with the engine 11, and a third rotating element connected with the engagement device; the clutch gear device includes a clutch 14, and a clutch gear connected to the clutch 14 and an engagement element, the clutch gear being connected to the output; the engaging device engages the third rotating element with the engaging element, or engages the third rotating element with the switch device, or engages only the third rotating element; the switch device locks or unlocks the third rotating element; the second motor 18 is arranged in parallel with the first motor 13, and the second motor 18 is connected to the output terminal. The hybrid power driving method of the invention can control the hybrid power driving system 10 to drive in each mode, and can ensure that each mode can be freely switched, so that the performance of the hybrid power driving system 10 reaches the optimum, the overall efficiency of the hybrid power driving system 10 is improved, and the power requirements of the system on the first motor 13 and the motor are reduced.

The present invention is not limited to the specific details of the above-described embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention. The various features described in the foregoing detailed description may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

Claims

1. A hybrid driving method for controlling a hybrid driving system to drive, the hybrid driving system comprising:

the clutch device comprises an engine, a first motor, a second motor, a planetary gear device, a clutch gear device, a connecting device and a switch device, wherein the engine and the first motor are both connected with the planetary gear device, and the clutch gear device is arranged between the first motor and the planetary gear device;

the planetary gear device includes a first rotating element connected with the first motor, a second rotating element connected with the engine, and a third rotating element connected with the engagement device;

the clutch gear device comprises a clutch, a clutch gear connected to the clutch and an engagement element, wherein the clutch gear is connected to the output end;

the engagement device engages the third rotating element with the engagement element, or engages the third rotating element with the switch device, or engages only the third rotating element;

the switch device locks or unlocks the third rotating element;

the second motor is arranged in parallel with the first motor and is connected to an output end;

the first rotating element is a sun gear, the second rotating element is a planet carrier, the third rotating element is a gear ring, the engagement device is a synchronizer, the switch device is a brake or a one-way clutch, and the clutch gear is a first gear;

the step of controlling the hybrid drive system to drive in a first-stage electric-only mode includes: the clutch does not work, the synchronizer is controlled to be arranged in an intermediate station, the engine and the first motor do not work, and the second motor is controlled to drive; the step of controlling the hybrid drive system to drive in a two-stage electric-only mode includes: controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, controlling the synchronizer to be arranged in an intermediate station, controlling the engine not to work, and driving the first motor and the second motor;

the step of controlling the hybrid power drive system to switch from the first-level electric-only mode to the second-level electric-only mode comprises the following steps:

2. The hybrid driving method according to claim 1, wherein the engagement device includes a first operation position, a second operation position, and a third operation position, the engagement device in the first operation position engages and fixes the third rotating element and the engagement element, the engagement device in the second operation position engages only the third rotating element, and the engagement device in the third operation position engages and fixes the third rotating element and the switch device.

3. A hybrid drive method as set forth in claim 1 wherein said first electric machine includes a first electric machine output shaft, said clutch gear device is disposed on said first electric machine output shaft, said clutch is connected to said first electric machine output shaft, said clutch gear is hollow in said first electric machine output shaft, and said engagement element is fixed to said clutch and is parallel to said clutch gear.

4. A hybrid drive method according to claim 1, wherein the first electric motor, the clutch gear device, the planetary gear device, and the engine are coaxially disposed.

5. The hybrid driving method according to claim 1,

the brake or the one-way clutch brakes or unlocks the gear ring;

6. A hybrid drive method as set forth in claim 5 wherein said hybrid drive system further comprises a differential having a differential gear disposed thereon, said countershaft further having a fourth gear disposed thereon, said fourth gear intermeshed with said differential gear.

7. The hybrid drive method of claim 5, wherein the step of controlling the hybrid drive system to switch from the secondary electric-only mode to the primary electric-only mode comprises:

8. The hybrid driving method according to claim 5, wherein the step of controlling the hybrid driving system to be driven in the range-extended mode includes: and controlling the synchronizer to be arranged at a right station, braking the gear ring by the brake or the one-way clutch, controlling the engine to drive the first motor to generate power, providing electric energy for the second motor by the first motor, and driving the second motor.

9. The hybrid drive method of claim 8, wherein the step of controlling the hybrid drive system to switch from the first-stage electric-only mode to the range-extended mode comprises:

10. A hybrid drive method as set forth in claim 8 wherein the step of controlling the hybrid drive system to switch from the range-extended mode to the primary electric-only mode comprises:

11. A hybrid drive method as set forth in claim 8 wherein the step of controlling the hybrid drive system to drive in a primary engine direct drive mode comprises: controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, the synchronizer to be placed at a left station is controlled, the gear ring is connected with the connecting element, the engine is controlled to drive, and the first motor and the second motor do not work; the step of controlling the hybrid power driving system to drive in the secondary engine direct drive mode comprises the following steps: and controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, controlling the synchronizer to be arranged at a right station, braking the gear ring by the brake or the one-way clutch, controlling the engine to drive, and preventing the first motor and the second motor from working.

12. A hybrid drive method as set forth in claim 11 wherein the step of controlling the hybrid drive system to switch from the range extended mode to the secondary engine direct drive mode comprises:

13. A hybrid drive method as set forth in claim 11 wherein the step of controlling the hybrid drive system to switch from the secondary engine direct drive mode to the range extended mode comprises:

14. A hybrid driving method according to claim 11, wherein the step of controlling the hybrid driving system to be driven in the one-stage hybrid mode includes: controlling the clutch to be out of work, controlling the synchronizer to be arranged at a left station, controlling the gear ring to be connected with the connecting element, controlling the engine to drive the planet carrier to rotate, controlling the first motor to drive the sun gear to rotate, and controlling the engine and the first motor to be in stepless coupling through the planetary gear device to control the second motor to drive; the step of controlling the hybrid drive system to drive in the two-stage hybrid mode comprises: controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, the synchronizer to be placed at a left station is controlled, the gear ring is engaged with the engaging element, and the engine, the first motor and the second motor are controlled to be driven; the step of controlling the hybrid drive system to drive in a three-stage hybrid mode includes: and controlling the clutch to work, wherein the clutch enables the first gear to be fixed on the output shaft of the first motor, controlling the synchronizer to be arranged at a right station, braking the gear ring by the brake or the one-way synchronizer, and controlling the engine, the first motor and the second motor to drive.

15. A hybrid drive method as set forth in claim 14 wherein the step of controlling the hybrid drive system to switch from the one-stage electric-only mode to the one-stage hybrid mode comprises:

16. A hybrid drive method as set forth in claim 14 wherein the step of controlling the hybrid drive system to switch from a one-stage hybrid mode to a one-stage electric-only mode comprises:

17. A hybrid drive method as set forth in claim 14 wherein the step of controlling the hybrid drive system to switch from a primary hybrid mode to a primary engine direct drive mode comprises:

18. A hybrid drive method as set forth in claim 14 wherein the step of controlling the hybrid drive system to switch from the primary engine direct drive mode to the primary hybrid mode comprises: