JP2021054155A - Hybrid vehicle power supply system - Google Patents

Abstract

To efficiently use generated electric power.SOLUTION: A hybrid vehicle power supply system includes a drive motor that serves as a driving source when a hybrid vehicle travels, an electric supercharger that comprises an electric motor, and a catalytic electric heater. Electric power, which is generated by the drive motor, is supplied to the electric motor or the catalytic electric heater by torque of an internal combustion engine or deceleration energy during the deceleration of the hybrid vehicle. The electric power, which is generated by the electric motor, is supplied to the drive motor by exhaust energy of exhaust gas.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a hybrid vehicle power supply system mounted on a hybrid vehicle including an internal combustion engine.

Conventionally, in a hybrid vehicle, the electric power generated by the motor due to the deceleration energy during deceleration is stored in the battery, and when the motor is driven, the electric power stored in the battery is supplied to the motor to drive the motor. ..

Further, conventionally, as a hybrid vehicle, when the exhaust temperature of the engine at the time of starting is low, the catalyst arranged in the exhaust passage is warmed up early by the heater at the same time as the start of running to improve the purification function of the catalyst at an early stage. Those that control the plan are known.

Further, conventionally, an electric turbocharger in which a motor is added to a turbocharger that compresses and pressurizes air supply is also known (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 6-50161

However, in the conventional hybrid vehicle electric power control system, there is a problem that the electric power generated by the motor cannot be fully utilized because a loss occurs due to repeated charging and discharging of the battery.

An object of the present disclosure is to provide a hybrid vehicle electric power supply system capable of efficiently using the generated electric power.

The hybrid vehicle power supply system according to the present disclosure is a hybrid vehicle power supply system mounted on a hybrid vehicle equipped with an internal combustion engine, and includes a drive motor and an electric motor which are drive sources when the hybrid vehicle travels. It has an electric supercharger that drives a turbine with exhaust gas from the internal combustion engine to increase the intake pressure of the internal combustion engine, and a catalytic electric heater that heats a catalyst that purifies the exhaust gas. The drive motor supplies the electric power generated by the torque of the internal combustion engine or the deceleration energy at the time of deceleration of the hybrid vehicle to the electric motor and / or the catalytic electric heater, and the electric motor uses the exhaust energy of the exhaust gas. The generated power is supplied to the drive motor.

According to the present disclosure, the electric power generated by the motor can be efficiently used in the hybrid vehicle.

It is a schematic diagram which shows the structure of the hybrid vehicle power supply system which concerns on embodiment of this disclosure. It is a flow chart which shows the operation at the time of the acceleration operation of the hybrid vehicle in the hybrid vehicle power supply system which concerns on embodiment of this disclosure. It is a flow chart which shows the operation at the time of deceleration operation of the hybrid vehicle in the hybrid vehicle power supply system which concerns on embodiment of this disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate.

<Structure of hybrid vehicle power supply system>
The configuration of the hybrid vehicle power supply system 1 according to the embodiment of the present disclosure will be described in detail below with reference to FIG.

The hybrid vehicle power supply system 1 according to the present embodiment is mounted on the hybrid vehicle 100 including the internal combustion engine 10. Here, the hybrid vehicle 100 is an HEV (hybrid electric vehicle), a PHEV (Plug-in Hybrid Electric Vehicle), or the like equipped with an internal combustion engine and a drive motor for traveling.

The hybrid vehicle 100 includes a hybrid vehicle power supply system 1, a large-capacity battery 2, a battery 3, a charge air cooler (hereinafter referred to as “CAC”) 4, a belt 5, an exhaust purification device 7, and a DC. It has a −DC converter 8, an internal combustion engine 10, and an Electrical Control Unit (hereinafter, referred to as “ECU”) 50. The hybrid vehicle power supply system 1, the large-capacity battery 2, the battery 3, and the DC-DC converter 8 are connected by a power line B.

Here, the large-capacity battery 2 is a high-voltage battery having a battery voltage of, for example, between 48 V and 300 V, which supplies the stored electric power to the drive motor 20 and the like. The battery 3 is a power source for driving electrical components, headlights, and the like, and is a small, small-capacity battery having a battery voltage of, for example, 12 V. The CAC 4 is an intercooler that cools the air compressed by the electric supercharger 30 and supplies it to the internal combustion engine 10. The belt 5 transmits power between the internal combustion engine 10 and the BAS (belt alternate starter) 6. In addition, this power transmission may be performed by other power transmission means such as gears instead of the belt.
The exhaust purification device 7 purifies the exhaust gas of the internal combustion engine 10 with a catalyst and discharges it to the outside. The exhaust gas purification device 7 is composed of, for example, a combination of a urea water system (SCR) that purifies NOx (nitrogen oxides) in the exhaust gas and an ammonia slip catalyst (ASC) that purifies the ammonia in the exhaust gas. There is. The internal combustion engine 10 drives the drive wheels of a hybrid vehicle by burning a mixture of fuel and air to rotate a crankshaft. The DC-DC converter 8 converts the direct current supplied from the large-capacity battery 2 or the battery 3 into a direct current of a predetermined voltage and supplies the direct current to the hybrid vehicle power supply system 1.

The hybrid vehicle power supply system 1 controls the power supply in the hybrid vehicle 100. Specifically, the hybrid vehicle power supply system 1 includes a BAS 6, a drive motor 20, an electric supercharger 30, a catalytic electric heater 40, and an ECU 50.

The BAS 6 generates electricity by being driven by the belt 5. Also. The BAS 6 rotates by the torque of the internal combustion engine 10 or the deceleration energy at the time of deceleration of the hybrid vehicle 100 to generate electricity. The BAS 6 also functions as a starter or an assist motor that assists in driving the internal combustion engine 10. The BAS 6 supplies the generated power to the drive motor 20, the electric motor 33 of the electric supercharger 30, or the catalytic electric heater 40 under the control of the ECU 50.

The drive motor 20 is a drive source when the hybrid vehicle travels, and drives the drive wheels of the hybrid vehicle 100 by receiving power from the large-capacity battery 2 or the electric motor 33 of the electric supercharger 30. Let me. The drive motor 20 supplies the electric power generated by the torque of the internal combustion engine 10 or the deceleration energy at the time of deceleration of the hybrid vehicle 100 to the electric motor 33 or the catalytic electric heater 40 under the control of the ECU 50. Under the control of the ECU 50, the drive motor 20 stores the surplus power that is not supplied to the electric motor 33 or the catalyst electric heater 40 among the generated power in the large-capacity battery 2.

The electric supercharger 30 is an electric turbo that raises the intake pressure of the internal combustion engine 10. Specifically, the electric supercharger 30 includes a compressor 31, a turbine 32, and an electric motor 33. The compressor 31 is driven by the driving torque of the turbine 32, compresses the outside air, and supplies it to the internal combustion engine 10 as supercharged air. The turbine 32 drives the compressor 31 by being driven by the exhaust gas of the internal combustion engine 10 and the electric motor 33. As a means for controlling the supercharging pressure, an electric compressor may be further provided, or may be provided in place of the electric supercharger 30.

The electric motor 33 is driven when power is supplied from the large-capacity battery 2, BAS 6 or the drive motor 20 to promote the drive of the compressor 31. The electric motor 33 rotates when the turbine 32 is driven, generates electric power by exhaust energy, and supplies the generated electric power to the drive motor 20 under the control of the ECU 50. When the electric motor 33 generates surplus electric power that is not supplied to the drive motor 20 among the generated electric power, the electric motor 33 stores the surplus electric power in the large-capacity battery 2.

The catalyst electric heater 40 receives power from the large-capacity battery 2, BAS 6, the drive motor 20, or the electric motor 33 when the temperature of the catalyst of the exhaust gas purification device 7 is low, such as when the internal combustion engine 10 is started. It is a catalyst heating device that heats and warms the catalyst at an early stage to improve the purification function of the catalyst at an early stage.

The ECU 50 controls the operation of the hybrid vehicle power supply system 1 and also controls the supply destination of the power generated by the BAS 6, the drive motor 20, and the electric motor 33.

<Operation of hybrid vehicle power supply system>
The operation of the hybrid vehicle power supply system 1 according to the embodiment of the present disclosure will be described in detail below.

First, the operation of the hybrid vehicle 100 during accelerated operation will be described in detail with reference to FIG. First, the drive motor 20 generates electricity by rotating with the torque of the internal combustion engine 10 when the electric supercharger 30 has a deviation from the target boost pressure at the time of acceleration or when the deviation is expected. (S11). The drive motor 20 generates electricity by generating surplus torque other than the torque required to drive the hybrid vehicle 100 out of the torque of the internal combustion engine 10 under the control of the ECU 50.

Next, the ECU 50 supplies the electric power generated by the hybrid vehicle drive motor 20 to the electric motor 33 of the electric supercharger 30 (electric turbo) to drive the electric motor 33 (S12).

Next, the ECU 50 determines whether or not there is surplus power in the power generated by the drive motor 20 (S13). The ECU 50 repeats the operation of step S12 when there is no surplus power (S13: NO). On the other hand, when there is surplus electric power (S13: YES), the ECU 50 determines whether or not the temperature of the catalyst of the exhaust gas purification device 7 is equal to or lower than a predetermined temperature (S14). The temperature of the catalyst of the exhaust gas purification device 7 is detected by, for example, a temperature sensor (not shown) provided in the exhaust gas purification device 7. When the temperature of the catalyst is equal to or lower than the predetermined temperature (S14: YES), the ECU 50 supplies the surplus electric power to the catalyst electric heater 40 (catalyst heater) (S15).

Next, the ECU 50 determines whether or not the power generation by the drive motor 20 is completed (S16). The ECU 50 ends its operation when the power generation by the drive motor 20 ends (S16: YES). On the other hand, the ECU 50 returns to the operation of step S13 when the power generation by the drive motor 20 is not completed (S16: NO).

Normally, the ECU 50 controls the amount of power generated by the drive motor 20 so that the electric supercharger 30 and the catalyst electric heater 40 do not generate excess power as much as possible. Therefore, in this normal case, that is, when the surplus power is not generated, the step (S17) of storing the power in the battery 3 is omitted.

On the other hand, when surplus power is generated, the operation of step S17 is added. That is, in step 14, when the temperature of the catalyst is higher than the predetermined temperature (S14: NO), the ECU 50 stores the surplus power in the large-capacity battery 2 (S17), and then performs the operation of step S16.

During the accelerated operation of the hybrid vehicle 100, the electric motor 33 receives power from the drive motor 20 to drive the hybrid vehicle 100 to increase the intake pressure of the internal combustion engine 10, so that the response in the running of the hybrid vehicle 100 can be improved.

Subsequently, the operation of the hybrid vehicle 100 during deceleration operation will be described in detail with reference to FIG. First, the drive motor 20 generates electricity by rotating with the deceleration energy during deceleration of the hybrid vehicle 100 (S21).

Next, when the ECU 50 determines that the hybrid vehicle 100 is decelerating based on the amount of change in vehicle speed detected by a vehicle speed sensor (not shown), is the temperature of the catalyst of the exhaust gas purification device 7 equal to or lower than a predetermined temperature? Whether or not it is determined (S22). When the temperature of the catalyst is equal to or lower than a predetermined temperature (S22: YES), the ECU 50 supplies the electric power generated by the drive motor 20 to the catalyst electric heater 40 (catalyst heater) to drive the catalyst electric heater 40 (catalyst heater). (S23).

Next, the ECU 50 determines whether or not there is surplus power in the power generated by the drive motor 20 (S24). The ECU 50 repeats the operation of step S23 when there is no surplus power (S24: NO). On the other hand, when there is surplus power (S24: YES), the ECU 50 stores the surplus power in the large-capacity battery 2 (S25).

Next, the ECU 50 determines whether or not the power generation by the drive motor 20 is completed (S26). The ECU 50 ends its operation when the power generation by the drive motor 20 ends (S26: YES). On the other hand, the ECU 50 returns to the operation of step S22 when the power generation by the drive motor 20 is not completed (S26: NO).

Further, in the operation of step S22, when the temperature of the catalyst is higher than the predetermined temperature (S22: NO), the ECU 50 skips to the operation of step S25.

When the hybrid vehicle 100 is decelerated, the temperature of the exhaust gas drops due to engine motoring. Therefore, the electric power generated by the drive motor 20 at the time of brake regeneration during deceleration is supplied to the catalyst electric heater 40 to warm up the catalyst at an early stage. To improve the purification function of the catalyst at an early stage. Here, engine motoring refers to compressing the intake air and exhausting the compressed air as it is without injecting fuel into the compressed air and burning it in the driving state of the internal combustion engine 10.

Finally, the operation of the hybrid vehicle 100 during high-speed, high-load operation will be described in detail. First, the electric motor 33 of the electric supercharger (electric turbo) 30 generates electricity by rotating with the surplus exhaust energy of the exhaust gas of the internal combustion engine 10.

Next, when the ECU 50 determines that the hybrid vehicle 100 is operating at high speed and with a high load based on the amount of change in vehicle speed detected by a vehicle speed sensor (not shown) and the accelerator opening degree detected by an accelerator opening sensor (not shown). , All of the electric power generated by the electric motor 33 is supplied to the drive motor 20.

Next, the ECU 50 determines whether or not the power generation by the electric motor 33 is completed, and when the power generation by the electric motor 33 is completed, the operation is terminated. On the other hand, when the power generation by the electric motor 33 is not completed, the ECU 50 continues to supply the electric power generated by the electric motor 33.

During high-speed, high-load operation of the hybrid vehicle 100, fuel consumption can be reduced by consuming the electric power generated by the electric motor 33 with the surplus exhaust energy of the exhaust gas by the drive motor 20.

As described above, according to the present embodiment, the drive motor 20 supplies the electric power generated by the torque of the internal combustion engine 10 or the deceleration energy at the time of deceleration of the hybrid vehicle 100 to the electric motor 33 or the catalytic electric heater 40 to supply the electric motor. 33 supplies the electric power generated by the exhaust energy of the exhaust gas to the drive motor 20, and the generated electric power is preferentially consumed by the other electric devices of the hybrid vehicle 100. Therefore, the generated electric power is used. It can be used efficiently.

Further, as a result, the capacity of the large-capacity battery 2 can be suppressed, the battery can be miniaturized, an increase in battery cost can be suppressed, and the battery can be made small. Since the weight and volume of the vehicle are also reduced, it is possible to suppress an increase in the vehicle weight, and it is also possible to save space, for example, to widen the riding space.

It should be noted that the present disclosure is not limited to the above-described embodiment in terms of the type, arrangement, number, etc. of the members, and deviates from the gist of the invention, such as appropriately replacing the constituent elements with those having the same effect and effect. Of course, it can be changed as appropriate as long as it is not.

Specifically, in the above-described embodiment, when surplus power is generated, the surplus power is stored in the large-capacity battery 2, but the ECU 50 is thoroughly controlled to generate power so as not to generate surplus power. Therefore, the large-capacity battery 2 may not be charged. In this case, the generated electric power can be efficiently consumed, and the battery can be further miniaturized.

The present disclosure is suitable for a hybrid vehicle power supply system mounted on a hybrid vehicle including an internal combustion engine.

1 Hybrid vehicle power supply system 2 Large capacity battery 3 Battery 4 CAC
5 Belt 6 BAS (Belt Alternate Starter)
7 Exhaust gas purification device 8 DC-DC converter 10 Internal combustion engine 20 Drive motor 30 Electric supercharger 31 Compressor 32 Turbine 33 Electric motor 40 Catalytic electric heater 50 ECU
100 hybrid vehicle

Claims (6)

A hybrid vehicle power supply system installed in a hybrid vehicle equipped with an internal combustion engine.
A drive motor, which is a drive source when the hybrid vehicle travels,
An electric supercharger having an electric motor and driving a turbine with exhaust gas from the internal combustion engine to increase the intake pressure of the internal combustion engine.
A catalyst electric heater that heats the catalyst that purifies the exhaust gas, and
Have,
The drive motor
The electric power generated by the torque of the internal combustion engine or the deceleration energy at the time of deceleration of the hybrid vehicle is supplied to the electric motor and / or the catalytic electric heater.
The electric motor
The electric power generated by the exhaust energy of the exhaust gas is supplied to the drive motor.
Hybrid vehicle power supply system. The drive motor
Of the power generated by the torque of the internal combustion engine or the deceleration energy, the surplus power that is not supplied to the electric motor and / or the catalytic electric heater is stored in the battery.
The hybrid vehicle power supply system according to claim 1. The electric motor
Of the electric power generated by the exhaust energy, the surplus electric power that is not supplied to the drive motor is stored in the battery.
The hybrid vehicle power supply system according to claim 1 or 2. The drive motor
Power is generated by surplus torque other than the torque required to drive the hybrid vehicle among the torques of the internal combustion engine.
The hybrid vehicle power supply system according to any one of claims 1 to 3. The drive motor
Of the electric power generated by the torque of the internal combustion engine, the surplus electric power that was not supplied to the electric motor is supplied to the catalytic electric heater.
The hybrid vehicle power supply system according to any one of claims 1 to 4. The drive motor
When the catalyst is at a predetermined temperature or lower, the electric power generated by the torque of the internal combustion engine or the deceleration energy is supplied to the catalyst electric heater.
The hybrid vehicle power supply system according to any one of claims 1 to 5.

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