JP2001304010A - Power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an over speed of a generator also efficiently operate a power plant. SOLUTION: A deviation ΔTm1 between target torque Tm1* of a generator and its maximum torque calculated to be based on an operating condition of an engine and the generator is obtained (S100 to S113), a surplus value M in accordance with the deviation ΔTm1 is set (S114 to S118), target torque Te* of the engine is limited to be based on the surplus value M (S120). The surplus value M, when the deviation ΔTml is smaller than a threshold value Tm1ref, is set as a large value as the deviation ΔTm1 decreases and as a temperature t goes down, when the deviation ΔTm1 is larger than the threshold value Tm1 ref, a value ML is set as a value not excessively limiting the target torque of the engine. In this way, an over speed of the generator can be prevented, also a device can be efficiently operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a power plant,
More specifically, the present invention relates to a power plant including an internal combustion engine and a generator that receives at least a part of the output of the internal combustion engine and generates power.

[0002]

2. Description of the Related Art Hitherto, as this type of power unit, there has been proposed a power unit that limits the output of an engine based on the maximum output of a generator (Japanese Patent Laid-Open No. 9-58301). In this device, when the output value of the generator corresponding to the target output value of the engine exceeds the maximum output value of the generator, the target output value of the engine is limited so as not to exceed the maximum output value of the generator. Prevents over-rotation of the generator.

[0003]

However, in such a power plant, the generator may overspeed due to the engine output exceeding the maximum output value of the generator. This is because the output value of the engine at the target output value of the engine may be larger than the target output value depending on the operation state of the engine. On the other hand, it is conceivable to provide a certain margin value for the maximum output value of the generator and set the target output value of the engine so as not to exceed a value due to a deviation between the maximum output value and the margin value. If the value is set low, the generator may over-rotate depending on the operation state of the engine, and if the margin value is set high, the output of the engine is restricted more than necessary.

[0004] It is an object of the power plant of the present invention to prevent the overspeed of the generator more reliably and to operate the device efficiently. It is another object of the power plant of the present invention to smoothly limit the output of an internal combustion engine and the output of a generator.

[0005]

The power unit of the present invention employs the following means in order to achieve at least a part of the above object.

A first power plant according to the present invention comprises: an internal combustion engine;
A power plant comprising: a generator configured to generate power by receiving at least a part of an output of the internal combustion engine; and an operation control unit configured to control operation of the internal combustion engine and the generator based on a required output. Operating state detecting means for detecting an operating state of the engine and / or the internal combustion engine, and output limiting value setting means for setting an output limiting value of the internal combustion engine with respect to a maximum output of the generator based on the detected operating state The gist is that the operation control means includes means for operating by limiting the output of the internal combustion engine using the output limit value set by the output limit value setting means.

In the first power plant of the present invention, the output limit value setting means is configured to output the internal combustion engine output with respect to the maximum output of the generator based on the operating state of the generator and the internal combustion engine detected by the operating state detecting means. The limit value is set, and the operation control means restricts the output of the internal combustion engine using the output limit value and operates. Therefore, in the first power plant of the present invention, it is possible to more appropriately limit the output of the internal combustion engine based on the operating state of the generator or the internal combustion engine. As a result, overspeed of the generator can be more reliably prevented.

[0008] In the first power plant of the present invention,
The output limit value setting means may be a means for setting a margin value with respect to a maximum output of the generator as the output limit value. In the first power plant of this aspect of the present invention, the output limit value setting means may be means for setting a larger value as the margin value as the output of the generator approaches the maximum output. . This way,
The overspeed of the generator can be more reliably prevented, and the device can be operated efficiently.

A second power unit according to the present invention includes an internal combustion engine,
A power generator that receives at least a part of the output of the internal combustion engine and generates power.
Operating state detecting means for detecting an operating state of the internal combustion engine; and target output calculating means for calculating a target output of the internal combustion engine and a target output of the generator based on the detected operating state and a required output. And, when the calculated target output of the generator exceeds a predetermined output, limiting the calculated target output of the internal combustion engine and the target output of the generator based on the calculated target output of the generator, respectively. Target output limiting means, and operation control means for controlling operation of the internal combustion engine and the generator such that the calculated or limited target output is output from the internal combustion engine and the generator, respectively. Make a summary.

In the second power plant according to the present invention, when the target output of the generator calculated based on the operating state of the generator or the internal combustion engine and the required output exceeds a predetermined output, the target output limiting means includes: Based on this target output, the target output of the internal combustion engine and the target output of the generator are each limited. The operation control means controls the operation of the internal combustion engine and the generator such that the calculated or limited target output is output from the internal combustion engine and the generator. Therefore, according to the second power plant of the present invention, each of the target output of the internal combustion engine and the target output of the generator is limited based on the operating state and the required output of at least one of the generator and the internal combustion engine. be able to.

In the second power plant of the present invention,
The predetermined output may be an output smaller than the maximum output of the generator by a predetermined value. By doing so, it is possible to limit the combination of the target output of the internal combustion engine and the target output of the generator near the maximum output of the generator.

Further, in the second power plant according to the present invention, the target output limiting means may be configured to reduce the output limit of the generator as the deviation between the calculated target output of the generator and the predetermined output increases. Then, it may be a means for greatly limiting the output limitation of the internal combustion engine. With this configuration, as the deviation between the target output of the generator and the predetermined output increases, the output of the internal combustion engine is greatly limited as compared with the output limit of the generator. Can be.

In the first and second power units of the present invention, the output shaft of the generator may be directly connected to the output shaft of the internal combustion engine, or the two shafts may be independently connected. An operable one shaft may be connected to the output shaft of the internal combustion engine via a three-shaft power transmission mechanism that operates in accordance with the operation of the two shafts.

[0014]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram schematically illustrating a configuration of a power unit 20 according to one embodiment of the present invention. The power unit 20 according to the embodiment exchanges power with an engine 30 that outputs power to a crankshaft 22 using gasoline as fuel, a planetary gear 40 having a planetary carrier connected to the crankshaft 22, and a sun gear shaft 24 of the planetary gear 40. A motor MG1 that performs power transmission, a motor MG2 that exchanges power with a drive shaft 28 connected to the ring gear shaft 26 of the planetary gear 40, and an electronic control unit 50 that controls the engine 30, the motor MG1, the motor MG2, and the like. .

Although not shown, the motors MG1 and MG2 are configured as synchronous motor-generators, in which a rotor having a plurality of permanent magnets on an outer peripheral surface and a three-phase coil forming a rotating magnetic field are wound. And a stator. This motor MG1 operates as a generator or a motor by the interaction between the magnetic field of the permanent magnet and the magnetic field formed by the three-phase coil. The motor MG1 and the motor MG2
Is connected to the battery 4 via the inverters 44 and 46, respectively.
2 is connected.

The electronic control unit 50 is configured as a microprocessor mainly including a CPU 52, and includes a ROM 54 storing a processing program, a RAM 56 temporarily storing data, and an input / output port (not shown). Prepare. The electronic control unit 50 includes a temperature t from a temperature sensor 48 for detecting an outside air temperature, an accelerator pedal position (depressed amount of the accelerator pedal 62) AP from an accelerator pedal position sensor 62a, and a brake pedal position from a brake pedal position sensor 64a. (Depression amount of brake pedal 64) BP, remaining capacity Bm from remaining capacity detector 38 for detecting remaining capacity of battery 42, rotation speed Ns of sun gear shaft 24 from rotation speed sensor 32, crank from rotation speed sensor 34 Number of rotations N of shaft 22
c, the rotation speed Nr of the ring gear shaft 26 from the rotation speed sensor 36, the vehicle speeds Vr, Vl from the vehicle speed sensors 66, 68 installed on the wheels, etc. are input via the input ports. Is the engine 30 and the motor M
Drive signals to G1 and the motor MG2 are output via the output port.

Next, the operation of the power unit of the embodiment constructed as described above, in particular, the engine 3 in the electronic control unit 50 will be described.
A process for limiting the output of 0 will be described. FIG. 2 is a flowchart illustrating an example of an engine drive control routine executed by the electronic control device 50 of the power plant 20. This routine is executed every predetermined time (for example, 10 msec).
This is repeatedly executed in c).

When this routine is executed, the CPU 52 of the electronic control unit 50 firstly determines the accelerator pedal position AP from the accelerator pedal position sensor 62a and the rotation speed Nr of the ring gear shaft 26 from the rotation speed sensor 36,
Processing for reading the remaining capacity Bm of the battery 42 from the remaining capacity detector 38 and the temperature t from the temperature sensor 48 is performed (step S100). The target torque Tr of the ring gear shaft 26 is determined based on the read accelerator pedal position AP and the rotation speed Nr of the ring gear shaft 26.
* Is calculated (step S102). In this embodiment, this processing is performed in accordance with the accelerator pedal position AP, the target torque Tr * of the ring gear shaft 26 and the ring gear shaft 2.
6 is stored in the ROM 54 as a map, and the accelerator pedal position AP and the ring gear shaft 2 are stored.
When the rotation speed Nr of 6 is given, the target torque Tr * of the ring gear shaft 26 corresponding to the map is derived. FIG. 3 shows an example of this map.

Subsequently, the energy Pr to be output to the ring gear shaft 26 is calculated (step S104), and the energy Pr, the remaining capacity Bm of the battery 42, and the engine 30 are calculated.
The energy Pe to be output by the engine 30 is calculated on the basis of the maximum energy that can be output from the ECU 30 (step S106), and the target torque Te * of the engine 30 is calculated based on the calculated energy Pe (step S106). Step S108). In the embodiment, the process of calculating the target torque Te * of the engine 30 is such that the engine 30 is operated in a state in which the efficiency of the engine 30 is as high as possible for each energy Pr, and the operating state of the engine 30 is changed in response to a change in the energy Pr. The operating point represented by the smoothly changing torque Te and the rotational speed Ne is obtained by an experiment or the like, and this is stored in advance in the ROM 54 as a map. When the energy Pr is given, the target torque is calculated from the operating point corresponding to the map. It is assumed that Te * is derived. FIG. 4 shows an example of this map. The curve A in the figure is obtained by connecting operating points at which the engine 30 can be operated as efficiently as possible with respect to the output energy of the engine 30 by continuous lines.

When the target torque Te * of the engine 30 is determined in this way, the target torque Tm1 * of the motor MG1 is calculated based on the gear ratio of the planetary gear 40 (step S110). FIG. 5 shows a calculation example based on the gear ratio of the planetary gear 40. And the motor MG
1 is limited to be equal to or less than the maximum torque Tm1max that can be output by the motor MG1 (steps S111 and S112), and a deviation ΔTm1 obtained by subtracting the target torque Tm1 * from the maximum torque Tm1max is calculated (step S113). This deviation ΔTm1 is equal to the threshold value Tm1re
A process is performed to determine whether the value is smaller than f (step S114). Here, the threshold value Tm1ref is used to set a range in which the output of the engine 30 is limited, and is determined based on characteristics of the engine 30 and the motor MG1.

When the deviation ΔTm1 is smaller than the threshold value Tm1ref, a margin value M is set based on the deviation ΔTm1 and the temperature t (step S116). This margin value M
Is set to be larger as the temperature t becomes lower and the deviation ΔTm1 becomes smaller. Specific numerical values are determined by the characteristics of the engine 30 and the motor MG1. In the embodiment, the deviation ΔTm1, the temperature t, and the margin M are stored in the ROM 54 in advance as a map, and when the deviation ΔTm1 and the temperature t are given, the margin M corresponding to the map is derived. FIG. 6 shows an example of this map. On the other hand, the deviation ΔTm1 is equal to the threshold value Tm1r
If it is larger than ef, it is determined that there is sufficient margin for the maximum torque Tm1max of the motor MG1, and a constant value ML is set as the margin value M (step S11).
8). The value ML is set as a value that does not excessively limit the target torque Tm1 * of the motor MG1, and a specific numerical value is determined by the characteristics of the engine 30, the motor MG1, and the like.

When the margin value M is set in this manner, the motor M
The target torque Te * of the engine 30 is limited so as not to exceed a value obtained by subtracting the margin value M from the maximum torque Tm1max of G1 (step S120).
Engine 30 so that target torque Te * of zero is output.
And drive control of the motor MG1 (step S12).
2) This routine ends.

According to the power unit 20 described above, the margin value M is determined based on the operating states of the engine 30 and the motor MG1.
Is changed to limit the target torque Te * of the engine 30, it is possible to prevent the motor MG1 from over-rotating even when the engine 30 outputs an unexpectedly high output based on the operating state. In addition, since the output of the engine 30 is not excessively limited, the capability of the device can be sufficiently exhibited.

In the power plant 20 of the embodiment, the margin value M is set based on the deviation ΔTm1 and the temperature t. However, the margin value M may be set based on the atmospheric pressure or the like. Alternatively, the margin value M may be set based only on the deviation ΔTm1.

Next, a power plant 20B according to a second embodiment of the present invention will be described. Power unit 20 of the second embodiment
The hardware configuration of B is the same as the hardware configuration of the power unit 20 of the first embodiment. Therefore, description of the hardware configuration of the power unit 20B of the second embodiment is omitted. In the power plant 20B of the second embodiment, an engine / motor drive control routine of FIG. 7 is executed instead of the engine drive control routine of FIG. This routine is executed at predetermined time intervals (for example,
It is repeatedly executed at 10 msec).

When the engine / motor drive control routine is executed, the CPU 52 of the electronic control unit 50 first executes the same processing as steps S100 to S110 in the routine of FIG. 2 (steps S200 to S210).
Then, the motor MG calculated in step S210
It is determined whether the first target torque Tm1 * is greater than a threshold value Tref (step S212). Here, the threshold T
ref is used as the lower limit of the target torque of the motor MG1 when limiting the output of the engine 30 and the motor MG1, and is set as a value lower than the maximum torque that the motor MG1 can output. The specific numerical value of the threshold value Tref is determined by the characteristics of the engine 30, the motor MG1, and the like.

When the target torque Tm1 * of the motor MG1 is larger than the threshold value Tref, a process for limiting the target torque Te * of the engine 30 and the target torque Tm1 * of the motor MG1 is performed (step S214). This process is performed by increasing the ratio of the limit amount of the target torque Te * of the engine 30 to the limit amount of the target torque Tm1 * of the motor MG1 as the target torque Tm1 * of the motor MG1 increases. In the embodiment, the target torque Tm1 *
The limit amount of the target torque Te * and the target torque Tm1 * after the restriction are obtained in advance through experiments or the like and stored in the ROM 54 as a map. When the target torque Tm1 * of the motor MG1 is given, the limit corresponding to the map is obtained. It is assumed that a later limit amount of the target torque Tm1 * and the target torque Te * is derived. One example of this map is shown in FIGS. The value T1 is set as the target torque Tm1 * of the motor MG1.
Is set, as shown in FIG. 8, the motor MG1
The torque of the amount corresponding to the area of the area B is restricted, and the torque value of the amount corresponding to the area of the area A is set as the target torque Tm1 * of the motor MG1 after the restriction. At the same time, the engine 30 is also limited by the amount of torque corresponding to the area of the region B. Also, the target torque Tm of the motor MG1
When the value T2 is set as 1 *, as shown in FIG.
The motor MG 1 is set with a maximum torque Tmax, which is an amount of torque corresponding to the area of the area A, and the amount of torque corresponding to the area of the area B is limited by the engine 30.

On the other hand, when the target torque Tm1 * of the motor MG1 is smaller than the threshold value Tref in the determination in step S212, the target torque Tm1 * of the motor MG1 has a sufficient margin with respect to the maximum torque.
The drive of the engine 30 and the motor MG1 is controlled without limiting the target torque Tm1 * of G1 and the target torque Te * of the engine 30 (step S216), and this routine ends.

The power unit 20B of the second embodiment described above.
According to this, the ratio between the limit amount of the target torque Te * of the engine 30 and the limit amount of the target torque Tm1 * of the motor MG1 is smoothly changed based on the operating state of the engine 30 and the motor MG1, and Drive control can be performed. Of course, it is possible to prevent the motor MG1 from over-rotating and to sufficiently exert the capability of the device because the output of the engine 30 is not excessively limited.

In each of the embodiments described above, a gasoline engine is used as the engine 30, but other internal combustion engines such as a diesel engine and a hydrogen engine may be used.

In each embodiment, the power units 20, 20
The engine B and the motor MG1 connected via the planetary gear 40 were used as B.
0 and the motor MG1 may be directly connected.

Further, in each of the embodiments, the case where the power unit is mounted on a vehicle has been described. However, the present invention is not limited to this. It can also be installed on a machine.

Although the embodiments of the present invention have been described with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing the configuration of a power unit 20 according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of an engine drive control routine executed by an electronic control unit of the power plant.

FIG. 3 is an explanatory diagram illustrating a map showing a relationship among a target torque Tr *, a rotation speed Nr, and an accelerator pedal position AP.

FIG. 4 is an explanatory diagram showing an example of a range in which the engine 30 can be operated efficiently.

FIG. 5 is an explanatory diagram showing the relationship between the rotation speed and the torque of the three shafts coupled to the planetary gear 40.

FIG. 6 is an explanatory diagram exemplifying a map showing a relationship between a deviation ΔTm1, a temperature t, and a margin value M;

FIG. 7 is a flowchart illustrating an example of an engine / motor drive control routine executed by the electronic control unit 50 of the power unit 20B.

FIG. 8 shows a limit amount of the target torque of the engine 30 with respect to the target torque Tm1 * of the motor MG1, and the motor M after the restriction.
FIG. 9 is an explanatory diagram illustrating a map indicating a relationship between a target torque of G1 and a target torque.

FIG. 9 is a diagram showing a limitation amount of a target torque of the engine 30 with respect to a target torque Tm1 * of the motor MG1, and the motor M after the limitation.
FIG. 9 is an explanatory diagram illustrating a map indicating a relationship between a target torque of G1 and a target torque.

[Explanation of symbols]

Reference Signs List 20 power unit, 22 crankshaft, 24 sun gear shaft, 26 ring gear shaft, 28 drive shaft, 30 engine, 32, 34, 36 rotation speed sensor, 38 remaining capacity detector, 40 planetary gear, 42 battery, 4
4, 46 inverter, 48 temperature sensor, 50 electronic control unit, 52 CPU, 54 ROM, 56 RA
M, 62 accelerator pedal, 62a accelerator pedal position sensor, 64 brake pedal, 64a brake pedal position sensor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 7/18 H02K 7/18 BF term (Reference) 3D035 AA01 3G093 AA16 AB01 BA06 BA19 CA07 CA08 DA01 DA05 DA06 DB03 DB04 DB15 DB26 DB28 EA02 EA05 EA09 EB08 EC01 EC02 FA03 5H115 PC06 PG04 PI24 PI29 PU10 PU24 PU25 PV09 QN03 QN27 SE04 SE05 TB03 TB10 TE02 TI02 TO05 TO21 TO23 5H607 AA14 BB01 BB02 BB07 BB09 BB14 CC03 CC05 EE33

Claims (8)

[Claims] An internal combustion engine, a generator that receives at least a part of an output of the internal combustion engine to generate power, and an operation control unit that controls operation of the internal combustion engine and the generator based on a required output. An operating state detecting means for detecting an operating state of the generator and / or the internal combustion engine; and limiting an output of the internal combustion engine to a maximum output of the generator based on the detected operating state. Output limiting value setting means for setting a value, wherein the operation control means limits the output of the internal combustion engine using the output limiting value set by the output limiting value setting means, and operates the power. apparatus. 2. The power plant according to claim 1, wherein the output limit value setting unit is a unit that sets a margin value with respect to a maximum output of the generator as the output limit value. 3. The power plant according to claim 2, wherein the output limit value setting means sets a larger value as the margin value as the output of the generator approaches the maximum output. 4. A power plant comprising: an internal combustion engine; and a generator for generating electric power by receiving at least a part of the output of the internal combustion engine, wherein the operation detects an operating state of the generator and / or the internal combustion engine. State detection means, target output calculation means for calculating a target output of the internal combustion engine and a target output of the generator based on the detected operation state and the required output, and a target output of the calculated generator When exceeds a predetermined output, target output limiting means for limiting the calculated target output of the internal combustion engine and the target output of the generator based on the calculated target output of the generator, respectively, the internal combustion engine and the A power plant comprising: operation control means for controlling operations of the internal combustion engine and the generator such that the calculated or limited target output is output from the generator. 5. The power plant according to claim 4, wherein the predetermined output is an output smaller than a maximum output of the generator by a predetermined value. 6. The target output limiting means limits the output limit of the internal combustion engine more as compared with the output limit of the generator as the deviation between the calculated target output of the generator and the predetermined output increases. The power plant according to claim 4, wherein the power unit is means for performing the operation. 7. The power plant according to claim 1, wherein an output shaft of the generator is directly connected to an output shaft of the internal combustion engine. 8. The output shaft of the internal combustion engine via a three-shaft power transmission mechanism in which two shafts can operate independently and one shaft operates in accordance with the operation of the two shafts. The power plant according to any one of claims 1 to 6, wherein the power plant is connected to a shaft.