JP2022138705A - Vehicular control device - Google Patents

Abstract

To provide a vehicular control device that can suppress decrease in output torque by a driving motor involved in completion of temporary power-up.SOLUTION: Output (generated electric power) of a power generation motor at the time of completing temporary power-up is predicted during the temporary power-up. A limit value of the output of the driving motor during the temporary power-up is set so that output (MG2 consumption power) of the driving motor at the time of completing the temporary power-up is not more than an additional value of the predicted value of the output of the power generation motor and electric power (output of a battery for MG2) determined by subtracting output other than output to the driving motor from rated power of a battery 11. During the temporary power-up, when the MG2 consumption power reaches the limit value, the MG2 consumption power is limited to the limit value until a limited time set in accordance with the limit value and an increase rate of the MG2 consumption power elapses thereafter.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle control device.

For example, a series hybrid vehicle (HV) is equipped with a generator motor that generates power from engine power and a drive motor that generates power for running. In addition, the hybrid vehicle is equipped with a battery that stores electric power used by the generator motor and the drive motor.

A hybrid vehicle is capable of HV running by generating electric power with the power of the engine and driving the drive motor with electric power obtained by combining the output of the generator motor and the output of the battery. In addition, the hybrid vehicle can run as an electric vehicle (EV) by driving the drive motor with the output of the battery without generating electricity by the generator motor while the engine is stopped. .

When a demand to accelerate the hybrid vehicle is generated during the EV running of the hybrid vehicle and the output required of the drive motor (required drive power) exceeds the output of the battery, the engine is started and the hybrid vehicle runs as an EV. It switches from running to HV running. When starting the engine, electric power is supplied from the battery to the generator motor, and the generator motor is powered, whereby the engine is cranked by the power of the generator motor.

A battery has a rated power, which is the upper limit of power that can be continuously output. In a hybrid vehicle equipped with a small-sized battery, when acceleration is requested during EV driving, the power required for engine cranking and the output of the drive motor to realize a response according to the acceleration request (intention of the driver). Since it is difficult to cover this with the rated power of the battery, a temporary increase in which the battery output is temporarily raised from the rated power may be performed.

JP 2014-101051 A

FIG. 3 is a graph showing an example of changes over time in the usable power of the drive motor, the power used by the drive motor, the power that can be output from the battery for the drive motor, and the output torque of the drive motor.

During the temporary power up, the power that can be output from the battery for the drive motor is the power (MG2 battery output) obtained by subtracting the output to other than the drive motor from the rated power of the battery, as indicated by the solid line (thin line). The electric power is obtained by adding the amount raised by the temporary increase (temporary increase). However, during engine cranking, power is used by the generator motor, so the available power for the drive motor (MG2 available power) is the battery output for MG2 plus the temporary increase, as indicated by the thick line. It is the electric power obtained by subtracting the amount used by the generator motor from the electric power generated. After the end of engine cranking, that is, after the engine is started, the power generated by the generator motor is no longer used, and power generation by the generator motor is started. It becomes the electric power which added the output of the motor (generated electric power).

On the other hand, the electric power used by the drive motor (the electric power used by MG2) monotonically increases as the drive motor rises, as indicated by the dashed line. When the power used by the drive motor reaches the power available for the drive motor, the power used by the drive motor is limited by the power available for the drive motor, as indicated by the overlapping of the thick and dashed lines. If the power used by the drive motor is limited by the available power of the drive motor before the temporary increase ends, the available power of the drive motor will decrease by the amount of the temporary increase when the temporary increase ends. Motor power consumption is reduced. When the electric power used by the drive motor is reduced, the output torque of the drive motor is reduced, and drivability is deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle control device that can suppress a decrease in the output torque of a drive motor due to termination of a temporary up.

In order to achieve the above object, a vehicle control device according to the present invention uses a battery, an engine, a generator motor that generates power with the power of the engine, and uses the output of the battery and the output of the generator motor as needed. A control device for use in a vehicle equipped with a drive motor that generates power for running as a vehicle, and capable of executing a temporary power-up that temporarily raises the upper limit of battery output from the rated power, the control device being used in parallel with the temporary power-up. a predicting means for obtaining a predicted value of the output of the generating motor at the end of the temporary increase when the generating motor is generating power, and limiting the output of the drive motor based on the predicted value obtained by the predicting means. and limiting means to

According to this configuration, in the vehicle, temporary power-up is performed to temporarily raise the upper limit of the output of the battery from the rated power.

For example, when the vehicle is running in EV mode by driving the drive motor with the engine stopped, if an acceleration request is generated by operating the accelerator, the engine is started and the running of the vehicle is switched from EV mode to HV mode. , while the generator motor generates power with the power of the engine, the drive motor is driven by the combined power of the output of the generator motor and the output of the battery. Since the output of the battery is used by the generator motor during cranking when starting the engine, the output of the battery may be temporarily insufficient, and in such a case, a temporary increase is performed.

Also, in vehicles equipped with an automatic air conditioner, when the ignition switch is turned on while the interior of the vehicle is hot, the cooling capacity is set to maximum and the interior of the vehicle is rapidly cooled down. During the cool-down, after the vehicle has started HV driving, if an acceleration request is generated by operating the accelerator, the output of the battery is temporarily deprived by the auto air conditioner, and the output of the battery is temporarily reduced. There may be a shortage, in which case temporary upgrades may be made.

In these cases, the temporary power-up and the power generation of the power generation motor are performed in parallel. When the temporary power-up ends, the usable power of the drive motor becomes the power obtained by subtracting the output to other than the drive motor from the rated power of the battery plus the output of the generator motor (generated power). If the motor output exceeds the drive motor power available, the drive motor output is reduced to the drive motor power available. The electric power used by the drive motor is the same as the output of the drive motor if losses in the drive motor are ignored.

Therefore, during the temporary increase, a predicted value of the output of the generator motor at the end of the temporary increase is obtained, and the output of the drive motor is limited based on the predicted value. As a result, it is possible to suppress a reduction in the power consumption of the drive motor at the end of the temporary increase, and to suppress a decrease in the output torque of the drive motor due to the reduction in the power consumption. As a result, it is possible to suppress the acceleration of the vehicle unintended by the driver, thereby improving the drivability.

The limiting means controls the driving so that the output of the driving motor at the end of the temporary increase is equal to or less than the sum of the predicted value obtained by the predicting means and the usable output of the driving motor within the rated power of the battery. Motor output may be limited.

With this configuration, the output of the drive motor becomes equal to or less than the usable electric power of the drive motor at the end of the temporary power-up, and it is possible to prevent the output torque from decreasing due to the decrease in the electric power used by the drive motor. As a result, it is possible to prevent the acceleration of the vehicle from being lowered unintentionally by the driver, thereby further improving the drivability.

According to the present invention, it is possible to suppress a reduction in the power consumption of the drive motor at the end of the temporary up, and to suppress a decrease in the output torque of the drive motor due to the reduction in the power consumption. As a result, it is possible to suppress the acceleration of the vehicle unintended by the driver, thereby improving the drivability.

1 is a block diagram showing the configuration of a main part of a hybrid vehicle; FIG. 5 is a graph showing an example of changes over time in usable power of a drive motor, used power of the drive motor, and power that can be output from a battery for the drive motor; Fig. 10 is a graph showing a conventional example of changes over time in usable electric power of a driving motor, usable electric power of the driving motor, electric power that can be output from a battery for the driving motor, and output torque of the driving motor;

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Main configuration of hybrid vehicle>
FIG. 1 is a block diagram showing the configuration of main parts of a hybrid vehicle 1. As shown in FIG.

The hybrid vehicle 1 is a vehicle equipped with a series hybrid system. A hybrid vehicle 1 is equipped with an engine 2, a generator motor (MG1) 3, and a drive motor (MG2) 4. As shown in FIG.

The engine 2 is, for example, a gasoline engine, and includes an electronic throttle valve for adjusting the amount of intake air into the combustion chamber, an injector (fuel injection device) for injecting fuel into the intake air, and a spark plug for generating electrical discharge in the combustion chamber. etc.

The generator motor 3 and the drive motor 4 are, for example, permanent magnet synchronous motors (PMSM).

The power generation motor 3 is a power generation motor that generates power using the power of the engine 2, and its rotating shaft is mechanically connected to the crankshaft of the engine 2 via a gear or the like.

The drive motor 4 is a drive motor that generates power for running the hybrid vehicle 1 , and has a rotation shaft connected to a drive system for running the hybrid vehicle 1 . The traveling drive system includes, for example, a differential gear, and the power of the drive motor 4 is transmitted to the differential gear, and is distributed and transmitted from the differential gear to the left and right drive wheels.

Also, the hybrid vehicle 1 is equipped with a battery (BAT) 11 and a PCU (Power Control Unit) 12 .

The battery 11 is an assembled battery in which a plurality of secondary batteries are combined. A secondary battery is, for example, a lithium ion battery. The battery 11 outputs DC power of about 200 to 150 V (volt), for example.

The PCU 12 is a unit for controlling the driving of the generator motor 3 and the drive motor 4, and includes inverters 13 and 14, a converter (CONV) 15 and an MGECU 16.

The inverter (INV1) 13 is a three-phase voltage source inverter that drives the generator motor 3, and includes a series circuit of two IGBTs (Insulated Gate Bipolar Transistors) for each of U-phase, V-phase and W-phase. They are provided corresponding to the phases, and have a configuration in which these series circuits are connected in parallel between the plus wiring and the minus wiring. The inverter 13 converts the DC power into AC power and supplies the AC power to the generator motor 3 during power running of the generator motor 3 . In addition, the inverter 13 converts AC power generated by the generator motor 3 into DC power when the generator motor 3 is in regenerative operation (power generation operation).

The inverter (INV2) 14 is a three-phase voltage source inverter that drives the drive motor 4. Similar to the inverter 13, the inverter (INV2) 14 is a series circuit of two IGBTs corresponding to each of the U-phase, V-phase and W-phase. and the series circuits are connected in parallel between the plus wiring and the minus wiring. The inverter 14 converts the DC power into AC power and supplies the AC power to the drive motor 4 during power running of the drive motor 4 . Further, the inverter 14 converts AC power generated by the drive motor 4 into DC power when the drive motor 4 is in regenerative operation (power generation operation).

Converter 15 boosts the DC power output from battery 11 and supplies it to inverters 13 and 14 when generator motor 3 and drive motor 4 are powered. Further, during regenerative operation of the generator motor 3 and the drive motor 4 , the DC power output from the inverters 13 and 14 is stepped down and supplied to the battery 11 .

The hybrid vehicle 1 is equipped with a plurality of ECUs (Electronic Control Units), and the MGECU 16 is one of the plurality of ECUs. Each ECU has a microcomputer (microcontroller), and the microcomputer contains, for example, a CPU, nonvolatile memory such as flash memory, and volatile memory such as DRAM (Dynamic Random Access Memory). A plurality of ECUs are connected so as to be capable of two-way communication using CAN (Controller Area Network) communication protocol.

The HVECU 17 is included in the plurality of ECUs. The HVECU 17 controls the engine 2 and also controls the generator motor 3 and the drive motor 4 via the PCU 12 . In controlling the generator motor 3 and the drive motor 4 , the torque command value of the generator motor 3 and the torque command value of the drive motor 4 are input from the HVECU 17 to the MGECU 16 . MGECU 16 controls operations of inverters 13 and 14 and converter 15 based on the torque command value input from HVECU 17 .

In the hybrid vehicle 1, when the engine 2 is started, electric power is supplied from the battery 11 to the generator motor 3, and the generator motor 3 is powered, whereby the engine 2 is motored (cranked) by the generator motor 3. . When the ignition plug of the engine 2 is sparked while the number of rotations of the engine 2 is increased to the number of rotations required for firing by motoring, the engine 2 fires.

When the hybrid vehicle 1 is running, the drive motor 4 is power-running, and the drive motor 4 generates power. In a state where the engine 2 is stopped and the generator motor 3 does not generate power, the drive motor 4 is driven by the output of the battery 11, so that the hybrid vehicle 1 performs EV running as an electric vehicle. Further, while the engine 2 is in an operating state (firing) and the generator motor 3 is in a power generation operation (regenerative operation), the drive motor is powered by the combined power of the output (generated power) of the generator motor 3 and the output of the battery 11. 4 is driven, the hybrid vehicle 1 performs HV running.

During deceleration of the hybrid vehicle 1, the drive motor 4 is regeneratively operated, and the power transmitted from the drive wheels to the drive motor 4 is converted into AC power. At this time, the drive motor 4 acts as a resistance of the traveling drive system, and the resistance acts as a braking force (regenerative braking force) for braking the hybrid vehicle 1 . Also at this time, the battery 11 is charged by supplying the electric power generated by the drive motor 4 to the battery 11 .

<Driving limit processing>
FIG. 2 is a graph showing an example of temporal changes in the power available for the drive motor 4, the power used by the drive motor 4, and the power that can be output from the battery 11 for the drive motor 4. In FIG.

For example, when the driver depresses the accelerator pedal while the hybrid vehicle 1 is running in an EV mode, an acceleration request is generated. While the generator motor 3 generates power with the motive power of the engine 2 , the drive motor 4 is driven by the combined power of the output of the generator motor 3 and the output of the battery 11 . Since the output of the battery 11 is used by the generator motor 3 during cranking when starting the engine 2, the output of the battery 11 may be temporarily insufficient. A temporary up is performed to temporarily raise the upper limit from the rated power. The rated power is power that can be continuously output from the battery 11 for a long period of time, and is set to a value that does not cause abnormalities such as thermal destruction even if the power is continuously output for a long period of time.

The power that can be output from the battery 11 for the drive motor 4 during the temporary power-up is, as indicated by the solid line (thin line), the power obtained by subtracting the output to other than the drive motor from the rated power of the battery 11 (hereinafter referred to as "MG2 This is the electric power obtained by adding the amount increased due to the temporary increase (temporary increase) to the output of the battery for use. However, since electric power is used by the generator motor 3 during cranking of the engine 2, the usable electric power of the drive motor 4 (hereinafter referred to as "MG2 usable electric power") is MG2 as indicated by the thick line. The amount of power used by the generator motor 3 is subtracted from the power obtained by adding the temporary increase to the battery output. After the cranking of the engine 2 is finished, the generator motor 3 stops using the electric power, and the generator motor 3 starts to generate power. The power is the sum of the outputs.

With the end of the temporary increase, the MG2 usable power is the sum of the MG2 battery output, the temporary increase, and the output of the generator motor 3, and the temporary increase is reduced. The power is the sum of the outputs of When the power consumption of the drive motor 4 (hereinafter referred to as "MG2 power consumption") exceeds the MG2 power consumption at the end of the temporary power-up, the MG2 power consumption is limited by the MG2 power consumption, and the drive motor 4 output will be reduced to MG2 available power.

Therefore, during the temporary up, the HVECU 17 predicts the output (generated electric power) of the generator motor 3 at the end of the temporary up. The speed at which the output of the generator motor 3 increases depends on the speed at which the rotation speed of the engine 2 increases. ratio of the amount of operation), the setting of the drive mode (motion characteristics) of the hybrid vehicle 1, and the like. Therefore, for example, for each of a plurality of drive modes (normal mode, sport mode, etc.), the relationship between the vehicle speed, the accelerator opening, and the predicted value of the output of the generator motor 3 at the end of the temporary increase is determined. The HVECU 17 acquires vehicle speed, accelerator opening and drive mode settings while the HVECU 17 is temporarily up, and stores the vehicle speed, accelerator opening and drive mode settings in the nonvolatile memory. A predicted value of the output of the generator motor 3 according to the setting of is obtained.

The HVECU 17 controls the output of the drive motor 4 during the temporary increase so that the output of the drive motor 4 at the end of the temporary increase is equal to or less than the sum of the predicted output of the generator motor 3 and the battery output for the MG2. limits are set. The power output of drive motor 4 is the same as the power used by MG2 if losses in drive motor 4 are ignored. When the MG2 power usage reaches the limit value during the temporary increase, the MG2 power usage is limited to the limit value until the time limit set according to the limit value and the increase rate of the MG2 power consumption has passed. .

<effect>
According to the above, the output of the drive motor 4 can be made equal to or less than the sum of the predicted output of the generator motor 3 and the output of the battery for MG2, that is, the usable power of the MG2 or less at the end of the temporary power-up. Therefore, it is possible to prevent the output of the drive motor 4 from decreasing at the end of the temporary up. As a result, it is possible to suppress the decrease in the output torque of the drive motor 4 at the end of the temporary up, suppress the decrease in the acceleration of the hybrid vehicle 1 due to the decrease in the output torque, and improve the drivability.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, in the above-described embodiment, the predicted value of the output of the generator motor 3 corresponding to the setting of the vehicle speed, accelerator opening, and drive mode is obtained from the relation stored in the nonvolatile memory. The predicted value of the output of the generator motor 3 at the end may be a fixed value that does not depend on the settings of the vehicle speed, the accelerator opening and the drive mode, or may be one of the settings of the vehicle speed, the accelerator opening and the drive mode. Alternatively, it may be a variable value depending on the two.

If the predicted value of the output of the generator motor 3 is a fixed value, the fixed value is set, for example, to the lowest value that ensures that the generator motor 3 is output at the end of the temporary up.

If the predicted value of the output of the generator motor 3 is a variable value, the actual value of the output of the generator motor 3 at the end of the temporary increase is obtained. /or the relationship between the drive mode setting and the predicted value may be updated.

In the above-described embodiment, the hybrid vehicle 1 equipped with a series hybrid system was taken up, but the present invention can be applied to a vehicle equipped with a hybrid system of a system other than the series system, such as a series/parallel system. In a series-parallel hybrid system, for example, an engine and a motor are connected to a planetary gear mechanism. Power can be combined and transmitted to the drive wheels.

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

1: Hybrid vehicle (vehicle)
2: engine 3: generator motor 4: drive motor 11: battery 17: HVECU (control device, prediction means, limit means)

Claims (2)

It is equipped with a battery, an engine, a generator motor that generates power with the power of the engine, and a drive motor that uses the output of the battery and the output of the generator motor as necessary to generate power for running. A control device used in a vehicle capable of temporarily raising the upper limit of the output of the battery from the rated power,
prediction means for obtaining a predicted output value of the power generation motor at the end of the temporary power-up when the power generation motor is generating power in parallel with the power-up;
and limiting means for limiting the output of the drive motor based on the predicted value obtained by the predicting means. The limiting means is configured such that the output of the drive motor at the end of the temporary power-up is an output obtained by adding the predicted value obtained by the predicting means and the usable output of the drive motor within the rated power of the battery. 2. The vehicle control device according to claim 1, wherein the output of said drive motor is limited so that:

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