WO2023084959A1

WO2023084959A1 - Electric vehicle

Info

Publication number: WO2023084959A1
Application number: PCT/JP2022/037508
Authority: WO
Inventors: 直樹宮本; 亮清水; 憲彦生駒
Original assignee: 三菱自動車工業株式会社
Priority date: 2021-11-10
Filing date: 2022-10-06
Publication date: 2023-05-19

Abstract

This electric vehicle, comprising a battery, a generator, a drive motor, and electrical devices, further comprises: a correction amount generation unit that generates a correction amount Δ which increases in accordance with a decrease amount when a charging state value of the battery decreases below a prescribed value; an adding unit that adds the correction amount Δ to a first power consumption value P1 calculated from a power consumption detection value of the electrical devices and calculates a second power consumption value P2; and a control unit that controls generated power by the generator on the basis of a power value including a vehicle drive power value Pd for driving the vehicle and the second power consumption value P2, and maintains the charging state value of the battery at a prescribed value or higher.

Description

electric vehicle

The present invention relates to control technology for an electric vehicle that runs by driving a motor (electric motor) with electric power.

In an electric vehicle, if the state of charge (SOC) of the battery drops beyond the limit, the battery is likely to deteriorate, and from the viewpoint of battery protection, it is necessary to avoid an excessive drop in SOC. For this reason, battery power management detects the power consumption of the drive motor and air conditioner as well as the power consumption of auxiliary equipment, and controls the power generated by the generator and the motor torque during regeneration.

For example, when the SOC drops to a discharge prohibition level, the generated power is increased to charge the drive battery, and the dischargeable power (or output limit power) SOP (Status Of Power) _out is limited to zero to stop discharging. Suppress. Patent Document 1 discloses a method of correcting SOP _out in order to prevent a drop in generated power. Patent Document 2 discloses a method for increasing the generated power by adjusting the input limit power SOP _in and the output limit power SOP _out . A method of adding correction power to generated power when the difference becomes small is disclosed.

Japanese Patent Application Laid-Open No. 2021-118558 Japanese Patent Application Laid-Open No. 2021-118559

However, the background art described above is premised on accurate detection of power consumption, and cannot be an effective countermeasure when there is a detection error. For example, the detected value of the power consumption of the accessory may be smaller than the actual value due to insufficient sensor or calculation accuracy. If the detected value is smaller than the actual accessory power consumption, the drive battery charge power during power generation or regenerative braking will be too small, and the remaining SOC of the drive battery may be depleted.

The aforementioned Patent Document 1 discloses countermeasures against transient excessive discharge power, and is not suitable for correcting stationary detection errors. Further, in Japanese Patent Application Laid-Open No. 2002-200010, since correction is performed according to the power difference between SOP _in and SOP _out , there is a possibility that the SOC decrease cannot be effectively prevented.

If the power consumption of onboard electronic components is not accurately detected in this way, and the detected power consumption value is smaller than the actual value, the charging power of the drive battery will be too small, and the actual remaining battery SOC will be depleted, possibly causing the vehicle to stop. become more sexual.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide an electric vehicle capable of avoiding an excessive decrease in SOC caused by an error in detecting power consumption and the resulting stoppage of the vehicle. .

In order to achieve the above object, one embodiment of the present invention provides a rechargeable battery, a generator capable of controlling generated power, a drive motor for driving a vehicle with power from the battery and/or the generator, and electrical equipment that consumes power, wherein the correction amount generation unit generates a correction amount that increases according to the amount of decrease in the state of charge value of the battery when the state of charge value of the battery drops below a predetermined value. an adding unit for calculating a second power consumption value by adding the correction amount to the first power consumption value calculated from the power consumption detection value of the electrical equipment; and a vehicle driving power value for driving the vehicle. and a control unit that controls the power generated by the generator based on the power value including the second power consumption value and maintains the state of charge value of the battery at the predetermined value or more.
Further, in one embodiment of the present invention, if the state of charge value of the battery is equal to or greater than the predetermined value, the correction amount is maintained at zero, and if it falls below the predetermined value, the correction amount is proportional to the decrease amount. The amount is increased, and the correction amount is provided with an upper limit value for overcharge protection.
Moreover, one embodiment of the present invention is characterized in that the predetermined value is a discharge prohibition value of the battery.
Further, an embodiment of the present invention is characterized in that the detection accuracy of the first power consumption detection value of the electrical equipment is lower than that of other detection values including the power consumption detection value of the drive motor. .
Further, according to one embodiment of the present invention, the generator is connected to the engine, and the control section controls the required torque to the engine and the generator.

According to one embodiment of the present invention, when the state-of-charge value of the battery drops below a predetermined value, a correction amount that increases according to the amount of decrease in the state-of-charge value is generated, and the correction amount is applied to the consumption of electrical equipment. By adding to the detected power value, even if the detected power consumption value of the electrical equipment is smaller than the actual power consumption (actual value), the power generated by the generator can be optimized, and the battery The state of charge value can be properly maintained to avoid vehicle stoppage.
Further, according to one embodiment of the present invention, the correction of the power consumption detection value of the electrical equipment is not executed until the decrease in the state of charge value of the battery reaches a predetermined value, and when the state of charge value decreases below the predetermined value, the decrease amount is calculated. By performing proportional correction, when the state of charge of the battery drops below a predetermined value, the amount of power generated increases according to the amount of decrease, and the state of charge of the battery is quickly optimized.
Further, according to the embodiment of the present invention, the predetermined value, which is the criterion for starting execution of the correction, is the battery discharge prohibition value, so that the vehicle stop due to insufficient battery charging power can be effectively avoided.
Further, according to one embodiment of the present invention, by correcting the power consumption detection value of electrical equipment whose detection or calculation accuracy is relatively low, the power consumption error is relatively low, such as for auxiliary equipment in a vehicle. Even if it is large, the state-of-charge value of the battery can be properly maintained to effectively prevent the vehicle from stopping.
Further, according to one embodiment of the present invention, the generated power is controlled by connecting the generator to the engine, so that in a so-called hybrid vehicle, the state of charge value of the battery can be properly maintained and the vehicle stop can be avoided.

1 is a block diagram showing a schematic configuration of an electric vehicle according to one embodiment of the present invention; FIG. FIG. 3 is a functional block diagram for explaining the operation of a vehicle ECU in the electric vehicle according to the present embodiment; 3 is a graph showing an example of a correction amount Δ of a correction amount generation unit shown in FIG. 2; 4 is a time chart showing an example of the operation of the control device according to the embodiment;

The electric vehicle 10 has a drive motor 101 , a battery 102 , a generator 103 , an engine 104 and accessories 105 . Further, as their control system, the electric vehicle 10 includes a vehicle ECU (Electronic Control Unit) 200, a MCU (Motor Control Unit) 201, a BMU (Battery Control Unit) 202, a GCU (Generator Control Unit). : generator control unit) 203 , an engine (ENG) ECU 204 , and an accessory ECU 205 . In FIG. 1, a solid line indicates a power line, a broken line indicates a communication line, and a circuit including an inverter and a DC-DC converter is configured between the battery 102, the drive motor 101, the generator 103 and the auxiliary equipment 105. , which is omitted here. Also, the electric vehicle 10 may be a PHEV (plug-in hybrid electric vehicle: a plug-in hybrid capable of external charging or external power supply).

The drive motor 101 operates using electric power to rotate the driving wheels of the electric vehicle 10, and regeneratively generates power to generate regenerative braking force when the electric vehicle 10 decelerates. A battery 102 stores power to operate the drive motor 101 . The power stored in the battery 102 includes, for example, power generated by a generator 103 described later, power generated by regenerative power generation of the drive motor 101, and power supplied by connecting an external power supply to a charging mechanism (not shown). In this embodiment, the output (discharge) power from the battery 102 is positive, and the input (charge) power to the battery 102 is negative.

The generator 103 is driven by the engine 104 and generates electric power to be used by the drive motor 101 and the accessories 105 of the electric vehicle 10 . A surplus of electric power generated by the generator 103 that is not used by the drive motor 101 or the auxiliary equipment 105 of the electric vehicle 10 is accumulated in the battery 102 . Further, the generator 103 generates electric power to be stored in the battery 102 when the charging rate SOC of the battery 102 becomes small. The engine 104 is an internal combustion engine that operates by burning fuel, and is connected to the rotating shaft of the generator 103 . Note that so-called parallel running, in which the engine 104 rotates the drive wheels of the electric vehicle 10 based on the running state of the electric vehicle 10, may be possible.

The vehicle ECU 200 is connected to the MCU 201, the BMU 202, the GCU 203, the engine ECU 204, and the accessory ECU 205, and controls the entire vehicle as a control device for the electric vehicle 10. Various sensors such as an accelerator pedal sensor that detects the operation amount AP of the accelerator pedal, a brake pedal sensor that detects the operation amount of the brake pedal, and a vehicle speed sensor that detects the vehicle speed V of the electric vehicle 10 are connected to the vehicle ECU 200. It is

The MCU 201 controls the drive motor 101, the BMU 202 the battery 102, the GCU 203 the generator 103, the engine ECU 204 the engine 104, and the accessory ECU 205 the accessories 105, respectively. Auxiliary equipment 105 includes electrical equipment that consumes electric power, such as an air conditioner electric compressor, front/rear glass heaters, heated door mirrors, and various lamps. As will be described later, BMU 202 outputs information such as SOC and temperature of battery 102 to vehicle ECU 200 as battery state quantities. Further, accessory ECU 205 calculates the electric power consumed by accessory 105 using a sensor value such as a DC-DC converter, and outputs the calculated accessory power consumption value P1 to vehicle ECU 200 .

The vehicle ECU 200 includes a processor such as a CPU (Central Processing Unit), a ROM (Read-Only Memory) for storing control programs and the like executed by the processor, a RAM (Random Access Memory) as a work area for the control program, and peripheral circuits. It is configured including an interface unit with etc. The control function according to this embodiment can be implemented by executing a program on the processor of vehicle ECU 200 .

The vehicle ECU 200 functioning as the control device according to this embodiment will be described in detail below. Although the present embodiment can be applied to on-vehicle electrical equipment whose power consumption detection accuracy is lower than that of the drive motor 101 and the like, the auxiliary equipment 105 is shown here as an example of such on-vehicle equipment. The reason for this is that the detected value of the power consumption of these auxiliary devices 105 may be smaller than the actual value due to insufficient sensor or calculation accuracy. According to this embodiment, as will be described in detail below, by correcting the power consumption calculation value of the auxiliary equipment 105 according to the SOC of the battery 102, the SOC can be prevented from exceeding its limit, or the SOC can be increased. can be made

As illustrated in FIG. 2, the vehicle ECU 200 has the following functions. A correction amount generation unit 301 generates a correction amount Δ described later, and an addition unit 302 adds the correction amount Δ to the auxiliary machine power consumption calculation value P1 calculated from the sensor detection value to obtain the auxiliary machine power consumption P2 (=P1+Δ). to output Addition unit 303 adds vehicle driving electric power Pd, accessory consumption electric power P2 input from addition unit 302 , and target charging electric power Ptc to generate target electric power generation Ptg (=Pd+P2+Ptc), and outputs the result to limiting unit 305 . . Here, vehicle drive power Pd varies depending on accelerator operation AP and vehicle speed V, and target charge power Ptc is set according to a decrease in SOC of battery 102 .

Addition unit 304 also adds motor power consumption Pm, accessory power consumption P2, and chargeable power Pcp to generate upper limit generated power Pug (=Pm+P2+Pcp) and outputs it to limit unit 305 . Here, the motor power consumption Pm is the power actually consumed by the drive motor 101, and the chargeable power Pcp varies depending on the battery 102 temperature. Limiting unit 305 outputs the smaller of target generated power Ptg and upper limit generated power Pug as requested generated power Prg, and requested generated power Prg is reflected in requested torque to engine 104 and generator 103 .

When the motor power consumption Pm becomes larger than the required power generation power Prg during high-load driving on an uphill road or a highway, not only the power of the generator 103 but also the power of the battery 102 is supplied to the drive motor 101. It becomes a discharge state. If the high-load running continues, the battery 102 cannot be charged according to the target charging power Ptc, and the chances of charging the battery 102 decrease. In addition, when the temperature of the battery 102 becomes low, the chargeable power Pcp is lowered, the upper limit generated power Pug is lowered, and the required generated power Prg is restricted, thereby reducing the chances of charging the battery 102 . Furthermore, if the auxiliary machine power consumption calculation value P1 is smaller than the actual value P0, the target generated power Ptg and the upper limit generated power Pug decrease, so the motor power consumption Pm relatively increases, and the chances of charging the battery 102 decrease. do. These conditions combine to reduce the chances of charging, resulting in a decrease in SOC. When the discharge of the battery 102 is prohibited due to the decrease in SOC, the output of the drive motor 101 is restricted so that the vehicle drive power Pd and the motor power consumption Pm match. When the SOC drops to the discharge prohibited level due to discharge, the target generated power Ptg is calculated using the accessory power consumption P2 (=P1+Δ) obtained by adding the correction amount Δ to the accessory power consumption calculation value P1, as will be described later. , the generated power can be increased by the correction amount Δ, and an excessive decrease in SOC can be prevented.

The functions illustrated in FIG. 2 are implemented by executing a program on the processor of vehicle ECU 200, and the functions of

adders

303, 304 and limiter 305 can use existing control configurations. Therefore, the characteristic function of this embodiment can be realized by the correction amount generation section 301 and the addition section 302 . This characteristic function will be described below.

As illustrated in FIG. 3, when the SOC of the battery 102 drops below a predetermined level, the correction amount generator 301 increases the correction amount Δ according to the amount of the drop. The correction amount .DELTA. for the SOC increases as the SOC falls below a predetermined level, thereby increasing the engine power generation amount to avoid a decrease in the SOC or to quickly raise the SOC to a predetermined level or higher.

The correction amount Δ illustrated in FIG. 3 does not correct the power consumption of the auxiliary equipment with the correction amount Δ=0 when the SOC is equal to or higher than the discharge prohibition value B1, provided that the predetermined level is the preset battery discharge prohibition SOC (region R1). . When the SOC drops below the discharge inhibition value B1, the correction amount Δ is increased according to the amount of SOC drop (region R2). Here, correction amount Δ is increased in proportion to the amount of SOC decrease from discharge inhibition value B1. However, the correction amount Δ is limited to a range in which the battery 102 is not overcharged, and the upper limit is set to _ΔUL here. Therefore, even if the SOC drops below the SOC value B2 (<B1) at which the correction amount Δ reaches the upper limit _ΔUL , the correction amount Δ does not increase any further (region R3).

Thus, even if the calculated value P1 of the power consumption of the accessory 105 is smaller than the actual power consumption (actual value) P0, the correction amount Δ is added to the calculated value P1 of the accessory power consumption. As a result, it is possible to optimize the generated power and avoid the situation where the SOC of the battery 102 excessively decreases. Hereinafter, the operation of the electric vehicle 10 to which the correction control according to this embodiment is applied will be described with reference to FIG.

As shown in FIG. 4B, when the calculated value P1 of the power consumption of the accessory 105 is smaller than the actual accessory power consumption P0 due to insufficient sensor or calculation accuracy, the underestimated accessory consumption A target power generation Ptg (=P1+Pd+Ptc) is generated by adding the vehicle drive power Pd and the target charging power Ptc to the power calculation value P1, and power is generated accordingly. As a result, the charging power of the battery 102 decreases, and the target charging power Ptc exceeds the chargeable power Pcp, so that the SOC of the battery 102, which tends to discharge, decreases to the discharge inhibition value B1 as shown in FIG. 4A. do.

Assuming that the SOC of battery 102 has decreased to discharge prohibition value B1 at time t1, vehicle ECU 200 (correction amount generation unit 301), as shown in FIG. Increase the correction amount Δ. As a result, the correction amount Δ is added to the auxiliary power consumption calculation value P1 to increase the auxiliary power consumption P2. Ptg (=P2+Pd+Ptc) is generated. Therefore, as shown in time points t1 to t2 in FIG. 4, the increase in the accessory power consumption P2 eliminates the underestimation of the accessory power consumption calculation value P1, and the engine generated power increases. As a result, the SOC recovers to the discharge inhibit level and is maintained.

As described above, according to the present embodiment, even if the calculated value P1 of the power consumption of the accessory 105 is smaller than the actual power consumption (actual value) P0, the calculated value of the accessory power consumption By adding the correction amount Δ to P1, it is possible to optimize the generated power as a result, and to avoid the situation where the SOC of the battery 102 excessively decreases.

Conventionally, as shown in FIG. 4B, engine power generation is performed with the underestimated accessory power consumption calculation value P1, so that the SOC drops beyond the discharge inhibition value while the battery 102 is in a discharged state. keep doing As a result, the battery 102 runs out of power at time t3 shown in FIG.

In contrast, according to the present embodiment, when the SOC drops to the discharge prohibition level, the correction amount Δ is added to the detected accessory power consumption calculation value P1 to increase the engine power generation amount. Such vehicle stop can be effectively avoided.

Various embodiments have been described above with reference to the drawings, but it goes without saying that the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the claims, and these also belong to the technical scope of the present invention. Understood. Moreover, each component in the above embodiments may be combined arbitrarily without departing from the spirit of the invention.

This application is based on a Japanese patent application (Japanese Patent Application No. 2021-183481) filed on November 10, 2021, the contents of which are incorporated herein by reference.

10 Electric Vehicle 101 Drive Motor 102 Battery 103 Generator 104 Engine 105 Auxiliary Equipment 200 Vehicle ECU (Electronic Control Unit)
201 Motor Control Unit (MCU)
202 battery control unit (BMU)
203 Generator Control Unit (GCU)
204 engine control unit (ENG ECU)
205 accessory control unit (auxiliary ECU)
301 correction amount generators 302 to 304 adder 305 limiter

Claims

An electric vehicle comprising a chargeable/dischargeable battery, a generator capable of controlling generated power, a drive motor that drives the vehicle with power from the battery and/or the generator, and electrical equipment that consumes the power. hand,
a correction amount generating unit that generates a correction amount that increases according to the amount of decrease in the state of charge value of the battery when the state of charge value of the battery drops below a predetermined value;
an addition unit that calculates a second power consumption value by adding the correction amount to the first power consumption value calculated from the power consumption detection value of the electrical equipment;
a control unit that controls the power generated by the generator based on the power value including the vehicle driving power value for driving the vehicle and the second power consumption value, and maintains the state of charge value of the battery at the predetermined value or higher; ,
An electric vehicle comprising:
If the state of charge value of the battery is equal to or greater than the predetermined value, the correction amount is maintained at zero, and if it falls below the predetermined value, the correction amount increases in proportion to the decrease amount, and the correction amount exceeds the correction amount. 2. The electric vehicle according to claim 1, wherein an upper limit value is provided for charging protection.
The electric vehicle according to claim 1, wherein the predetermined value is a discharge prohibition value of the battery.
The electric vehicle according to claim 2, wherein the predetermined value is a discharge prohibition value of the battery.
The electric vehicle according to claim 1, wherein the detected power consumption value of the electrical equipment has a lower detection accuracy than other detected values including the detected power consumption value of the drive motor.
The electric vehicle according to claim 2, wherein the power consumption detection value of the electrical equipment has lower detection accuracy than other detection values including the power consumption detection value of the drive motor.
The electric vehicle according to claim 3, wherein the power consumption detection value of the electrical equipment has lower detection accuracy than other detection values including the power consumption detection value of the drive motor.
The electric vehicle according to claim 4, wherein the detected power consumption value of the electrical equipment has lower detection accuracy than other detected values including the detected power consumption value of the drive motor.
The electric vehicle according to any one of claims 1 to 4, wherein the generator is connected to an engine, and the control unit controls torque required to the engine and the generator.