JP2023093777A - Hybrid vehicular control apparatus - Google Patents

Abstract

To provide a hybrid vehicular control apparatus capable of generating an exact amount power for driving a motor.SOLUTION: A hybrid vehicle 1 has a control apparatus 10 that includes a calculation part 11 and a control part 12. The calculation part 11 calculates shortage power that is a value obtained by subtracting battery upper-limit power being an upper limit of power that a battery 30 can supply to motors 22, 27, from vehicle consumption power being power to be consumed for driving the hybrid vehicle 1 in a parallel mode. The control part 12 controls operation states of an engine 21 and a generator 23 so that the generator 23 generates the shortage power in the parallel mode.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hybrid vehicle control device having a parallel mode.

2. Description of the Related Art Conventionally, in a hybrid vehicle equipped with an engine, an electric motor, and a generator, there is known a technique for controlling the amount of power generated by the generator according to the power that the battery can output. For example, there is a method of predicting the battery's possible output power based on the required voltage to be applied to the electric motor, the battery SOC (state of charge), and the battery temperature, and determining the target power generation of the generator according to this battery's possible output power. Proposed. Such a method can prevent shortage of electric power for driving the electric motor (see Patent Document 1).

Patent No. 3714405

Electric power output from the battery is used not only to drive the electric motor but also to drive auxiliary equipment mounted on the vehicle. Therefore, if the generated power is set based only on the battery's output power, the power actually consumed by the vehicle may exceed the battery's output power. In this case, the electric power for driving the electric motor becomes insufficient, and the driving feeling of the vehicle deteriorates. Moreover, even if there is surplus electric power for driving the electric motor, it will be wasted if the surplus electric power cannot be charged to the battery.

One of the purposes of the present invention is to provide a hybrid vehicle control device that can generate just the right amount of electric power for driving a motor. do. In addition to this purpose, it is another object of the present invention to achieve functions and effects derived from each configuration shown in the "Mode for Carrying out the Invention" described later and which cannot be obtained with conventional techniques. can be positioned.

The disclosed hybrid vehicle control device includes an engine and a motor connected to driving wheels, a generator driven by the engine, and a battery connected to the motor and the generator, wherein the driving force of the engine and the motor is transferred to the driving wheels. A control device for a hybrid vehicle having a parallel mode for transmission and running. The control device is provided with a calculation section and a control section. In the parallel mode, the calculation unit calculates the power shortage, which is the value obtained by subtracting the battery upper limit power, which is the upper limit of the power that the battery can supply to the motor, from the vehicle power consumption, which is the power consumed to drive the hybrid vehicle. calculate. The control unit controls the operating states of the engine and the generator so that the generator generates the insufficient power in the parallel mode.

According to the disclosed control device, it is possible to generate just the right amount of electric power for driving the motor.

1 is a schematic diagram of a vehicle to which a control device as an embodiment is applied; FIG. 2 is a block diagram showing the configuration of the vehicle in FIG. 1; FIG. 2 is a block diagram showing the configuration of the electronic control unit of FIG. 1; FIG. FIG. 2 is a block diagram showing the contents of processing in the electronic control unit of FIG. 1; FIG.

[1. Device configuration]
A vehicle 1 to which a hybrid vehicle control apparatus according to an embodiment is applied will be described with reference to FIGS. 1 to 4. FIG. This vehicle 1 is a hybrid vehicle having a parallel mode in which driving power output from both an internal combustion engine and an electric motor is transmitted to driving wheels for running. The vehicle 1 of this embodiment includes a front wheel drive device 2 for driving the front drive wheels (front wheels), a rear wheel drive device 3 for driving the rear drive wheels (rear wheels), A battery 30 for and an electronic control unit 10 are mounted.

As shown in FIG. 2, the front wheel drive device 2 includes an engine 21 (internal combustion engine), a front motor 22 (front wheel electric motor), a generator 23 (generator), a front motor inverter 24, a generator inverter 25, and a front transaxle. 26 (front wheel transmission). The rear wheel drive device 3 includes a rear motor 27 (rear wheel electric motor), a rear motor inverter 28, and a rear transaxle 29 (rear wheel transmission). A battery 30 is connected to each of the front motor 22 , the generator 23 and the rear motor 27 . When the running mode of the vehicle 1 is the parallel mode, both the driving force of the front motor 22 and the rear motor 27 and the driving force of the engine 21 are transmitted to the drive wheels to drive the vehicle 1 .

As for the running modes, the vehicle 1 is provided with three running modes: an EV mode, a series mode, and a parallel mode. These driving modes are alternatively selected according to the driving state, and the engine 21, the motors 22, 27, and the generator 23 are selectively used according to the type. The EV mode is a driving mode in which the vehicle 1 is driven only by the motors 22 and 27 while the engine 21 and generator 23 are stopped. The series mode is a driving mode in which the generator 23 is driven by the engine 21 to generate power, and the electric power is used to drive the vehicle 1 by the motors 22 and 27 . The parallel mode is a driving mode in which the driving force of the engine 21 and the motors 22, 27 is transmitted to the drive wheels to drive.

In the parallel mode of the vehicle 1 of this embodiment, the driving force generated by the engine 21 is transmitted to the drive wheels and the generator 23 . Electric power generated by the generator 23 is supplied to the motors 22 and 27 via the battery 30 . As a result, even if the charge amount of the battery 30 decreases during the parallel mode, part of the output of the engine 21 can be recovered as electric power by the generator 23, and the charge amount of the battery 30 can be restored. Further, by continuing to operate at least the rear motor 27 in the parallel mode, even if the front motor 22 is stopped, the driving force can be transmitted to the front and rear wheels, the four-wheel drive state is maintained, and the steering stability of the vehicle is maintained. It is possible to prevent deterioration of

The front motor 22 and the rear motor 27 are, for example, three-phase AC synchronous motors, and have a function of generating driving force for the vehicle 1 with the electric power of the battery 30 and a function of generating power using the inertial force of the vehicle 1. Have both. The generator 23 is, for example, a three-phase AC synchronous generator, and has a function of rotating the crankshaft of the engine 21 with the power of the battery 30 (starter function) and a function of generating power using the rotational power of the engine 21. and Each of transaxles 26 and 29 is a power transmission device incorporating a transmission and a final drive gear. The front transaxle 26 is connected to the wheel shafts connected to the left and right front wheels, the engine 21 , the front motor 22 and the generator 23 . The rear transaxle 29 is connected to the rear motor 27 and a wheel shaft that connects the left and right rear wheels.

The battery 30 is, for example, a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The front motor inverter 24 is a power conversion device for converting DC power on the battery 30 side and AC power on the front motor 22 side. It is a power conversion device for converting AC power on the side. The rear motor inverter 28 is a power conversion device for converting DC power on the battery 30 side and AC power on the rear motor 27 side. Each of the inverters 24, 25, 28 incorporates an inverter circuit including a switch element. Each output of the front motor 22, the generator 23, and the rear motor 27 is controlled by controlling the operating state of the inverter circuit (opening/closing timing and opening/closing frequency of the switch element).

The operating states of the inverters 24, 25, 28 and the engine 21 are controlled by an electronic control unit 10 (computer). As shown in FIG. 3, the electronic control unit 10 contains a processor (central processing unit), a memory (main memory), a memory (storage), an interface device, and the like. Communicatively connected. Also connected to the electronic control unit 10 are a vehicle speed sensor 13, a brake sensor 14, an accelerator sensor 15, an engine 21, a front motor inverter 24, a generator inverter 25, and a rear motor inverter . The vehicle speed sensor 13 is a sensor that detects the running speed (vehicle speed) of the vehicle 1 . The brake sensor 14 is a sensor that detects the amount of depression of the brake pedal (the amount of brake operation). The accelerator sensor 15 is a sensor that detects the depression amount of the accelerator pedal (accelerator operation amount). The electronic control unit 10 controls the operating states of various devices mounted on the vehicle 1 based on the information detected by these sensors 13-15.

[2. Control configuration]
As shown in FIGS. 1 and 4, at least a calculator 11 and a controller 12 are provided inside the electronic control unit 10 . These elements classify and show the functions of the electronic control unit 10 for convenience. The calculator 11 calculates the power shortage when the running mode of the vehicle 1 is the parallel mode. The power shortage is a parameter corresponding to the vehicle power consumption, which is the power consumed to drive the vehicle 1, minus the battery upper limit power, which is the upper limit of the power that the battery 30 can supply.

The control unit 12 controls the operational states of at least the engine 21 and the generator 23 so that the power shortage calculated by the calculation unit 11 is generated by the generator 23 when the running mode of the vehicle 1 is the parallel mode. is. By this control, a part of the output of the engine 21 operating in the parallel mode is used for power generation by the generator 23, and the generated power is supplied to the motors 22, 27 and auxiliary equipment. The accessories here include a cooling device for cooling the engine 21 and the motors 22 and 27, an air conditioner, an audio device, and the like.

As shown in FIG. 4, the calculation unit 11 of the electronic control unit 10 in this embodiment includes a battery upper limit power calculation unit 31, a vehicle power consumption calculation unit 32, a power shortage calculation unit 33, a parallel power generation output calculation unit 34, a request A power generation output calculator 35 and a maximum engine drive shaft torque calculator 36 are provided. The control unit 12 is also provided with a generator control unit 37 , a front motor control unit 38 , a rear motor control unit 39 and an engine control unit 40 . Each element shown in FIG. 4 can be described as an independent program, or can be described as a composite program combining multiple elements. A program corresponding to each element shown in FIG. 4 is stored in the memory or storage device of the electronic control unit 10 and executed by the processor.

The battery upper limit electric power calculator 31 calculates the battery upper limit electric power [W], which is the upper limit of electric power that the battery 30 can supply to the motors 22 and 27 and the accessories. The battery upper limit power is a parameter that represents the instantaneous discharge capability of the battery 30, and is calculated based on the SOC (state of charge) and SOH (degree of deterioration) of the battery 30, battery temperature, battery voltage, and the like. Information on the battery upper limit power calculated here is transmitted to the power shortage calculator 33 .

The vehicle power consumption calculator 32 calculates vehicle power consumption [W], which is the total power consumed to drive the vehicle 1 . The vehicle power consumption calculated here includes at least the rear motor driving power converted into the driving force by the rear motor 27 and the auxiliary machine power consumption consumed by the auxiliary machines. Preferably, the motor loss (front motor loss, rear motor loss), which is the loss of the motors 22 and 27, and the generator loss, which is the loss of the generator 23, are also included in the vehicle power consumption. Information on the vehicle power consumption calculated here is transmitted to the power shortage calculator 33 .

The power shortage calculation unit 33 calculates power shortage [W], which is a value obtained by subtracting the battery upper limit power calculated by the battery upper limit power calculation unit 31 from the vehicle power consumption calculated by the vehicle power consumption calculation unit 32. is. The power shortage calculator 33 always calculates the power shortage while at least the running mode of the vehicle 1 is the parallel mode. If the battery upper limit power is greater than the vehicle power consumption, the power shortage is assumed to be zero. The power shortage calculated here has a value of 0 or more. The power shortage value represents the amount of power that is substantially insufficient for running the vehicle 1 . Information on the power shortage calculated here is transmitted to the parallel power generation output calculator 34 .

The parallel power generation output calculator 34 calculates the parallel power generation output, which is the electric power that the engine 21 causes the generator 23 to generate in the parallel mode. First, the surplus electric power that can be generated by the generator 23 when the engine 21 is operated at the optimum fuel efficiency point is calculated. The surplus electric power is obtained, for example, by subtracting the output required for the front wheels of the vehicle 1 from the output (maximum engine output) obtained when the engine 21 is operated at the best fuel consumption point.

Also, the parallel power generation output calculation unit 34 selects one of the surplus power and the shortage power that has a large value, and calculates the parallel power generation output based on the selected one. For example, the one selected here is subjected to a predetermined filter process assuming a response delay of the engine 21, and is calculated as the parallel power generation output. Information on the parallel power generation output calculated here is transmitted to the required power generation output calculation section 35 and the maximum engine drive shaft torque calculation section 36 .

The required power generation output calculation unit 35 calculates a required power generation output for generating a control signal for causing the generator 23 to generate power based on the parallel power generation output. Here, for example, when the traveling mode of the vehicle 1 is the parallel mode, the parallel power generation output is directly calculated as the required power generation output. Further, when the running mode of the vehicle 1 changes, the required power generation output corrected based on the operating state of the engine 21, the state of the clutch incorporated in the front transaxle 26, and the like is calculated. Information on the required power generation output calculated here is transmitted to the generator control section 37 and the engine control section 40 of the control section 12 .

The maximum engine drive shaft torque calculator 36 calculates the maximum engine drive shaft torque, which is the maximum torque that can be transmitted from the engine 21 to the front wheels in the parallel mode. Here, the maximum engine drive shaft torque is calculated by subtracting the generated torque consumed by the generator 23 from the maximum engine torque and multiplying the result by a predetermined reduction ratio. The power generation torque is obtained by dividing the parallel power generation output calculated by the parallel power generation output calculation unit 34 by the rotation speed of the generator 23 and then multiplying the result by a predetermined torque conversion factor. Information on the maximum engine drive shaft torque calculated here is transmitted to the front motor control section 38 of the control section 12 .

The generator control section 37 controls the operating state of the generator 23 by outputting a control signal to the generator inverter 25 based on the required power generation output calculated by the required power generation output calculation section 35 . Here, the generator 23 is controlled so as to obtain a power generation amount corresponding to the required power generation output (in other words, so that the power shortage calculated by the calculator 11 in the parallel mode is generated by the generator 23).

The front motor control unit 38 sends a control signal to the front motor inverter 24 based on the torque exceeding the maximum engine drive shaft torque calculated by the maximum engine drive shaft torque calculation unit 36 with respect to the drive torque required for the front wheels. By outputting it, the operating state of the front motor 22 is controlled. Here, when the driving torque required for the front wheels can be covered by the output of the engine 21 alone, the front motor 22 is controlled to be in a non-operating state. On the other hand, when the output of the engine 21 alone is not enough, the front motor 22 is driven. As for the method of calculating the drive torque required for the drive wheels (front and rear wheels) and the method of driving the front motor 22, known control methods can be applied, and the description thereof will be omitted in this embodiment.

The rear motor control unit 39 controls the operating state of the rear motor 27 by outputting a control signal to the rear motor inverter 28 . Here, the operating state of the rear motor 27 is controlled so that the driving torque required for the rear wheels is generated. Electric power for driving the rear motor 27 is supplied from the battery 30 . Note that even if the battery upper limit power of the battery 30 is lower than the vehicle power consumption, the generator 23 generates power for the shortage, so the output of the rear motor 27 is ensured.

The engine control unit 40 controls the operating state of the engine 21 by outputting a control signal to the engine 21 (or engine ECU, fuel injection device, throttle valve, valve mechanism, etc.). The operating state of the engine 21 in the parallel mode is controlled so as to operate at an operating point based on the drive torque required for the front wheels and the required power generation output calculated by the required power generation output calculator 35 . The operating state of the engine 21 in the series mode is controlled so that the generator 23 generates electric power according to the operating states of the motors 22 and 27 and the state of charge of the battery 30 .

[3. action, effect]
(1) The calculation unit 11 (vehicle power consumption calculation unit 32) calculates the amount of power that the battery 30 can supply to the motors 22 and 27 from the vehicle power consumption, which is the power consumed to drive the vehicle 1 in the parallel mode. A power shortage, which is a value obtained by subtracting the upper limit of battery power, which is the upper limit of power, is calculated. Further, the control unit 12 controls the operating states of the engine 21 and the generator 23 so that the generator 23 generates the insufficient electric power in the parallel mode. With such control, the electric power for driving the motors 22 and 27 can be generated in just the right amount. As a result, it is possible to prevent the system from shutting down due to, for example, power shortage and the deterioration of driving feeling.

(2) The vehicle power consumption calculated by the calculator 11 includes motor power consumption, generator loss, and accessory power consumption. In this way, by controlling the operating states of the engine 21 and the generator 23 in consideration of various losses and the power consumption of the auxiliary equipment, it is possible to accurately suppress excess or deficiency of power. Therefore, the controllability and driving feeling of the vehicle 1 can be improved.

(3) Motor power consumption of the rear motor 27 and motor loss of the front motor 22 in the vehicle 1 having the engine 21 connected to the front wheels and the rear motor 27 connected to the rear wheels, as shown in FIG. is included in the vehicle power consumption, it is possible to suppress the excess or deficiency of power while maintaining the four-wheel drive state during the parallel mode. Therefore, the running performance and steering stability performance of the vehicle 1 can be improved.

(4) The calculation unit 11 (parallel power generation output calculation unit 34) calculates whichever of the surplus power and the shortage power generated by the generator 23 when the engine 21 is operated at the best fuel efficiency point has a larger absolute value. A parallel power generation output is calculated based on either one. By such calculation, when the shortage of power exceeds the surplus power, the shortage of power can be generated by the generator 23, and the occurrence of excess or deficiency of power can be suppressed. On the other hand, when the power shortage is less than the surplus power, the parallel power generation output can be calculated based on the surplus power, and power shortage can be reliably prevented while operating the engine 21 efficiently.

(5) The control unit 12 operates the engine 21 at the best fuel consumption point in the parallel mode, and adjusts the operating state of the generator 23 so that part of the torque generated by the engine 21 is allocated to the parallel power generation output. Control. With such control, the fuel consumption performance of the engine 21 can be improved, and electric power for driving the motors 22 and 27 can be generated in just the right amount.

Note that the control unit 12 calculates the engine output by adding the front wheel drive output and the power generation output. The control unit 12 operates the engine 21 at a fuel efficiency point by adjusting the power generation output in accordance with the front wheel drive output corresponding to the accelerator operation (normal operation during hybrid running). Here, when the power shortage is small and the generated power for the fuel consumption point operation is larger, the engine 21 operates at the fuel consumption point as it is. On the other hand, if the power shortage cannot be resolved, the power shortage will be covered by power generation. At this time, the engine 21 outputs torque greater than the fuel efficiency point torque.

[4. Modification]
The above embodiment is merely an example, and is not intended to exclude various modifications and application of techniques not explicitly described in this embodiment. Each configuration of this embodiment can be modified in various ways without departing from the scope of the invention. Also, they can be selected or combined as needed. For example, in the above embodiment, the structure in which the front wheel drive device 2 and the rear wheel drive device 3 are separately provided was illustrated, but a structure in which the driving force is distributed to the front and rear wheels via a propeller shaft may also be used. good. At least, if the hybrid vehicle has a parallel mode, control similar to that of the present embodiment can be performed.

1 vehicle 2 front wheel drive device 3 rear wheel drive device 10 electronic control unit 11 calculator 12 control unit 21 engine 22 front motor 23 generator 27 rear motor 30 battery

Claims (5)

The vehicle includes an engine and a motor connected to driving wheels, a generator driven by the engine, and a battery connected to the motor and the generator, and transmits the driving force of the engine and the motor to the driving wheels. A control device for a hybrid vehicle having a parallel mode of running,
In the parallel mode, a power shortage, which is a value obtained by subtracting a battery upper limit power, which is the upper limit of the power that the battery can supply to the motor, from vehicle power consumption, which is the power consumed to drive the hybrid vehicle. a calculating unit for calculating;
a control unit that controls operating states of the engine and the generator so that the generator generates the insufficient power in the parallel mode;
A control device for a hybrid vehicle, comprising: The calculation unit sums the motor driving power converted into the driving force by the motor, the motor loss that is the loss of the motor, the generator loss that is the loss of the generator, and the accessory consumption power consumed by the accessory. 2. The control device for a hybrid vehicle according to claim 1, wherein said vehicle power consumption is calculated according to said vehicle power consumption. The control device for the hybrid vehicle, wherein the motor includes a front motor for driving front wheels and a rear motor for driving rear wheels, and the engine is connected to the front wheels,
The calculating unit calculates the vehicle power consumption by summing the motor drive power of the rear motor, the motor loss of each of the front motor and the rear motor, the generator loss, and the accessory power consumption. 3. The hybrid vehicle control device according to claim 2, wherein: The calculation unit calculates in the parallel mode based on either surplus power, which is power generated by the generator when the engine is operated at the best fuel efficiency point, or the shortage power, whichever has a larger absolute value. The control device for a hybrid vehicle according to any one of claims 1 to 3, wherein a parallel power generation output, which is the electric power that the engine causes the generator to generate, is calculated. The controller controls the operating state of the generator so that in the parallel mode, the engine is operated at the best fuel consumption point and part of the torque generated by the engine is allocated to the parallel power generation output. 5. The hybrid vehicle control device according to claim 4, characterized in that:

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