阅读说明：本技术 车辆的电源系统 (Power supply system for vehicle ) 是由 广瀬素久 江原夏树 有贺畅幸 泷泽一晃 于 2021-03-16 设计创作，主要内容包括：本发明的目的在于提供一种车辆的电源系统,可以防止高压蓄电池的残余量在用户不知情的情况下显著降低。为了解决上述问题,电源系统具备：电压转换器,用于连接设置低压蓄电池的低压电路与设置高压蓄电池的高压电路；充电控制部,用于实行辅助充电控制,所述辅助充电控制操作电压转换器,并利用高压电路中的电力对低压蓄电池进行充电；BCM,用于接受用户所进行的开启操作或关闭操作；辅助充电时点设定部,用于设定辅助充电时点。充电控制部在发动机停止时间未到达辅助充电允许期间的情况下,在辅助充电时点设定部所设定的辅助充电时点实行辅助充电控制,并且在发动机停止时间比辅助充电允许期间更长的情况下,不实行辅助充电控制。(The invention aims to provide a power supply system of a vehicle, which can prevent the residual quantity of a high-voltage storage battery from being remarkably reduced under the condition that a user does not know. In order to solve the above problem, a power supply system includes: the voltage converter is used for connecting a low-voltage circuit provided with a low-voltage storage battery with a high-voltage circuit provided with a high-voltage storage battery; a charge control section for carrying out an auxiliary charge control that operates the voltage converter and charges the low-voltage secondary battery with electric power in the high-voltage circuit; the BCM is used for receiving opening operation or closing operation performed by a user; and an auxiliary charging time setting unit for setting an auxiliary charging time. The charging control unit executes the auxiliary charging control at the auxiliary charging time set by the auxiliary charging time setting unit when the engine stop time does not reach the auxiliary charging allowable period, and does not execute the auxiliary charging control when the engine stop time is longer than the auxiliary charging allowable period.)

1. A power supply system for a vehicle, comprising:

a low-voltage circuit provided with a low-voltage power storage device;

a high-voltage circuit provided with a high-voltage power storage device having a higher voltage than the low-voltage power storage device;

a charging circuit connecting the low-voltage circuit and the high-voltage circuit;

a charging control scheme for carrying out an auxiliary charging control that operates the aforementioned charging circuit and charges the aforementioned low-voltage electrical storage device with electric power in the aforementioned high-voltage circuit;

an operation acceptance scheme for accepting an opening operation or a closing operation performed by a user for starting or stopping the aforementioned vehicle;

a timing setting means for setting a charging timing at which the auxiliary charging control is executed during a vehicle stop period from when the turning-off operation is received to when the turning-on operation is received; and a process for the preparation of a coating,

wherein the aforementioned charge control scheme executes the aforementioned auxiliary charge control at the charge time set by the aforementioned time setting scheme in the case where the engine stop time, that is, the time elapsed since the acceptance of the aforementioned shut-down operation, does not reach the specified 1 st time, and does not execute the aforementioned auxiliary charge control in the case where the aforementioned engine stop time is longer than the aforementioned 1 st time.

2. The vehicular power supply system according to claim 1, wherein the foregoing charging control scheme ends the foregoing auxiliary charging control in a case where a remaining amount of the foregoing low-voltage electric storage device after the foregoing auxiliary charging control is started exceeds a specified 1 st remaining amount, or in a case where a charging duration, that is, an elapsed time after the foregoing auxiliary charging control is started, exceeds a specified 2 nd time.

3. The vehicular power supply system according to claim 2, wherein the timing setting means sets a next charging timing after the end of the auxiliary charging control, and sets a later one of a period calculated based on the remaining amount of the low-voltage power storage device and a predetermined period as the charging timing when the auxiliary charging control is ended when the charging duration exceeds the 2 nd time.

4. The vehicular power supply system according to any one of claims 1 to 3, wherein the aforementioned operation acceptance scheme accepts a 1 st turn-on operation for starting the aforementioned vehicle into a running mode,

wherein the charging control scheme operates the charging circuit while the vehicle is traveling, and the normal charging control for charging the low-voltage power storage device with electric power in the high-voltage circuit and the auxiliary charging control may be selectively executed,

wherein the charging control scheme shifts from the auxiliary charging control to the normal charging control in a case where the 1 st on operation is accepted during execution of the auxiliary charging control.

5. The vehicular power supply system according to any one of claims 1 to 3, wherein the aforementioned operation acceptance scheme accepts a 2 nd turn-on operation by a user for starting the aforementioned vehicle into an accessory mode in which a state of replenishment is available,

wherein the charge control scheme ends the auxiliary charge control when the 2 nd turn-on operation is accepted during the execution of the auxiliary charge control.

6. The power supply system for a vehicle according to any one of claims 1 to 3, comprising a communication scheme for accepting a communication start operation of the portable terminal by a user for starting the vehicle in a communication mode in which communication with the portable terminal outside the vehicle is possible,

wherein the charge control scheme ends the auxiliary charge control when the communication start operation is accepted during execution of the auxiliary charge control, and thereafter restarts the auxiliary charge control when the remaining amount of the low-voltage power storage device does not reach a specific 2 nd remaining amount.

7. A power supply system for a vehicle, comprising:

a low-voltage circuit provided with a low-voltage power storage device;

a high-voltage circuit provided with a high-voltage power storage device having a higher voltage than the low-voltage power storage device;

a charging circuit connecting the low-voltage circuit and the high-voltage circuit;

a charging control scheme for carrying out an auxiliary charging control that operates the aforementioned charging circuit and charges the aforementioned low-voltage electrical storage device with electric power in the aforementioned high-voltage circuit;

an operation acceptance scheme for accepting an opening operation or a closing operation performed by a user for starting or stopping the aforementioned vehicle;

a timing setting means for setting a charging timing at which the auxiliary charging control is executed during a vehicle stop period from when the turning-off operation is received to when the turning-on operation is received;

a remaining amount acquisition means for acquiring a remaining amount of the high-voltage power storage device; and a process for the preparation of a coating,

wherein the charge control scheme executes the auxiliary charge control at the charge time set by the time setting scheme in a case where the remaining amount of the high-voltage power storage device is larger than a specific 3 rd remaining amount, and does not execute the auxiliary charge control in a case where the remaining amount does not reach the 3 rd remaining amount.

Technical Field

The present invention relates to a power supply system for a vehicle. More specifically, the present invention relates to a power supply system that charges a low-voltage power storage device with electric power of a high-voltage power storage device while a vehicle is stopped.

Background

A power supply system mounted on an electric vehicle or a hybrid vehicle includes a high-voltage battery that stores electric power mainly for supplying to a driving motor for running and a low-voltage battery that has a lower voltage than the high-voltage battery and stores electric power mainly for supplying to a machine. For example, patent document 1 discloses a power supply system for an electric vehicle in which a high-voltage circuit provided with a high-voltage battery and a low-voltage circuit provided with a low-voltage battery are connected via a voltage converter. In the power supply system of patent document 1, when the low-voltage battery is insufficiently charged, the voltage converter reduces the voltage of the power of the high-voltage battery to charge the low-voltage battery. Hereinafter, charging of the low-voltage battery with the electric power of the high-voltage battery is referred to as auxiliary charging.

[ Prior art documents ]

(patent document)

Patent document 1: japanese patent laid-open No. 2000-341801

Disclosure of Invention

[ problems to be solved by the invention ]

In addition, the dark current gradually reduces the remaining amount of the low-voltage battery while the vehicle is stopped. Therefore, if the vehicle is stopped for a long time, the residual amount of the low-voltage battery will be lower than the minimum residual amount required for starting the vehicle, and the vehicle may not be started. In order to solve such a problem, it is conceivable to periodically perform the auxiliary charging as described above while the vehicle is stopped. However, in this case, since the auxiliary charging is repeatedly performed, the remaining amount of the high-voltage battery may be significantly reduced without the user's knowledge.

The present invention aims to provide a power supply system for a vehicle, which can prevent the residual amount of a high-voltage battery from being significantly reduced without the user's knowledge by performing auxiliary charging of a low-voltage battery using electric power of the high-voltage battery while the vehicle is stopped.

[ means for solving the problems ]

(1) A power supply system (e.g., a power supply system 1) of a vehicle (e.g., a vehicle V) according to the present invention includes: a low-voltage circuit (e.g., a low-voltage circuit 3 described later) provided with a low-voltage power storage device (e.g., a low-voltage battery B2 described later); a high-voltage circuit (for example, a high-voltage circuit 2 described later) provided with a high-voltage power storage device (for example, a high-voltage battery B1 described later) having a higher voltage than the low-voltage power storage device; a charging circuit (for example, a voltage converter 4 described later) that connects the low-voltage circuit and the high-voltage circuit; a charging control scheme (for example, a charging control unit 701 described later) for performing an auxiliary charging control that operates the charging circuit and charges the low-voltage power storage device with electric power in the high-voltage circuit; an operation acceptance pattern (for example, a BCM72, a power switch 83, a brake pedal 84, and the like described later) for accepting an on operation or an off operation by a user for starting or stopping the vehicle; a timing setting means (for example, an auxiliary charging timing setting unit 702 described later) for setting a charging timing at which the auxiliary charging control is executed during a vehicle stop period from when the closing operation is received to when the opening operation is received; and wherein the charge control scheme executes the auxiliary charge control at the charge time set by the time setting scheme in a case where the engine stop time, that is, the time elapsed since the shutdown operation was accepted, does not reach a specific 1 st time (for example, an auxiliary charge allowable period described later), and does not execute the auxiliary charge control in a case where the engine stop time is longer than the 1 st time.

(2) In this case, it is preferable that the charge control scheme ends the auxiliary charge control when a remaining amount (for example, a charge rate described later) of the low-voltage power storage device after the auxiliary charge control is started exceeds a specific 1 st remaining amount (for example, a target charge rate described later), or when a charge duration, that is, a time elapsed after the auxiliary charge control is started, exceeds a specific 2 nd time (for example, an upper limit time described later).

(3) In this case, it is preferable that the timing setting means sets the next charging timing after the end of the auxiliary charging control, and sets a later one of a period calculated based on the remaining amount of the low-voltage power storage device and a predetermined period as the charging timing when the auxiliary charging control is ended when the charging duration exceeds the 2 nd time.

(4) In this case, it is preferable that the operation acceptance scheme accepts a 1 st on operation for starting the vehicle in a running mode, wherein the charge control scheme operates the charge circuit while the vehicle is running, and may selectively execute normal charge control for charging the low-voltage power storage device with electric power in the high-voltage circuit and the auxiliary charge control, and wherein the charge control scheme shifts from the auxiliary charge control to the normal charge control when the 1 st on operation is accepted during execution of the auxiliary charge control.

(5) In this case, it is preferable that the operation acceptance scheme accepts a 2 nd turn-on operation performed by a user for turning on the vehicle in the accessory mode, and the charging control scheme ends the auxiliary charging control when accepting the 2 nd turn-on operation during execution of the auxiliary charging control.

(6) In this case, it is preferable that the power supply system includes a communication scheme (for example, a telematics ECU73 and a communication module 74) for receiving a communication start operation of a portable terminal (for example, a portable terminal 85) outside the vehicle by a user in order to start the vehicle in a communication mode in which the portable terminal can communicate with the vehicle, wherein the charging control scheme ends the auxiliary charging control when the communication start operation is received during execution of the auxiliary charging control, and then restarts the auxiliary charging control when the remaining amount of the low-voltage power storage device does not reach a specific 2 nd remaining amount (for example, a start-up guaranteed charging rate).

(7) A power supply system (e.g., a power supply system 1) of a vehicle (e.g., a vehicle V) according to the present invention includes: a low-voltage circuit (e.g., a low-voltage circuit 3 described later) provided with a low-voltage power storage device (e.g., a low-voltage battery B2 described later); a high-voltage circuit (for example, a high-voltage circuit 2 described later) provided with a high-voltage power storage device (for example, a high-voltage battery B1 described later) having a higher voltage than the low-voltage power storage device; a charging circuit (for example, a voltage converter 4 described later) that connects the low-voltage circuit and the high-voltage circuit; a charging control scheme (for example, a charging control unit 701 described later) for performing an auxiliary charging control that operates the charging circuit and charges the low-voltage power storage device with electric power in the high-voltage circuit; an operation acceptance pattern (for example, a BCM72, a power switch 83, a brake pedal 84, and the like described later) for accepting an on operation or an off operation by a user for starting or stopping the vehicle; a timing setting means (for example, an auxiliary charging timing setting unit 702 described later) for setting a charging timing at which the auxiliary charging control is executed during a vehicle stop period from when the closing operation is received to when the opening operation is received; a remaining amount acquisition means (for example, a management ECU71 and a high-voltage battery sensor 81 described later) for acquiring a remaining amount of the high-voltage power storage device; and wherein the charge control scheme executes the auxiliary charge control at the charge time set by the time setting scheme when a remaining amount (e.g., a charge rate described later) of the high-voltage power storage device is larger than a specific 3 rd remaining amount (e.g., an auxiliary charge prohibition charge rate described later), and does not execute the auxiliary charge control when the remaining amount does not reach the 3 rd remaining amount.

(Effect of the invention)

(1) In the present invention, the timing setting means sets the charging timing, that is, the execution timing of the auxiliary charging control during the vehicle stop period from the time when the off operation by the user is accepted to the time when the on operation is accepted. The charging control scheme executes the auxiliary charging control at the charging time set by the time setting scheme, when the engine stop time, that is, the time elapsed since the shutdown operation was received, does not reach the specific 1 st time. This can prevent the remaining amount of the low-voltage power storage device from excessively decreasing while the vehicle is stopped. In addition, the charging control scheme does not perform the auxiliary charging control in the case where the engine stop time is longer than the 1 st time. This prevents the remaining amount of the high-voltage power storage device from being significantly reduced by repeating the auxiliary charging control during a long-time vehicle stop exceeding the 1 st time.

(2) For example, when the low-voltage power storage device is in a low-temperature environment, the charging efficiency is lower than when the low-voltage power storage device is in a normal-temperature environment. Therefore, if it is desired to continue the auxiliary charging control in a low-temperature environment until the remaining amount of the low-voltage power storage device reaches the 1 st remaining amount, the charging time may be extended, and the power consumption amount of the high-voltage power storage device further increases along with the auxiliary charging control. In contrast, in the present invention, the charge control scheme ends the assist charge control in the case where the remaining amount of the low-voltage power storage device after the start of the assist charge control exceeds the 1 st remaining amount, or in the case where the charge duration, that is, the elapsed time after the start of the assist charge control, exceeds the 2 nd time. Thereby, it is possible to prevent the residual amount of the high-voltage power storage device in the low-temperature environment from being unexpectedly significantly reduced due to the auxiliary charging control.

(3) In the present invention, the timing setting means sets the next charging timing after the end of the auxiliary charging control, and sets the later of the period calculated based on the remaining amount of the low-voltage power storage device and the predetermined period as the charging timing when the auxiliary charging control is ended when the charging duration exceeds the 2 nd time. Thereby, it is possible to prevent the remaining amount of the high-voltage power storage device from being significantly reduced due to the repeated execution of the auxiliary charging control at a high frequency in a low-temperature environment such as a charging duration time exceeding the 2 nd time.

(4) In the present invention, when the 1 st on operation for starting the vehicle in the running mode is accepted during execution of the auxiliary charging control, the charging control scheme shifts from the auxiliary charging control in execution to the normal charging control. Thus, the low-voltage power storage device can be continuously charged without interfering with the interrupt operation performed by the user.

(5) In the present invention, the charge control scheme ends the auxiliary charge control when a 2 nd turn-on operation for starting the vehicle in the accessory mode is accepted while the auxiliary charge control is being executed. This prevents the user from being hindered from using the auxiliary charging control while the auxiliary charging control is being executed with excessive priority.

(6) In the present invention, the charging control scheme terminates the auxiliary charging control when the communication start operation of the portable terminal by the user is accepted while the auxiliary charging control is being executed. This prevents the user from being hindered from operating the portable terminal because the auxiliary charging control is performed with too high priority.

(7) In the present invention, the timing setting means is used to set the charging timing at which the auxiliary charging control is executed by the charging control means during a vehicle stop period from when the turning-off operation by the user is accepted to when the turning-on operation is accepted, and the remaining charge acquisition means is used to acquire the remaining charge of the high-voltage power storage device. In the charge control scheme, when the remaining charge of the high-voltage power storage device is larger than the 3 rd remaining charge, the auxiliary charge control is executed at the charge time set by the time setting scheme. This can prevent the remaining amount of the low-voltage power storage device from excessively decreasing while the vehicle is stopped. In addition, the charging control scheme does not perform the auxiliary charging control in the case where the remaining amount of the high-voltage electrical storage device does not reach the 3 rd remaining amount. This prevents the remaining amount of the high-voltage power storage device from decreasing below the 3 rd remaining amount by repeating the auxiliary charging control while the vehicle is stopped.

Drawings

Fig. 1 is a diagram showing the configuration of a vehicle mounted with a power supply system according to an embodiment of the present invention.

Fig. 2 is a diagram showing the configuration of the electronic control unit group.

Fig. 3 is a graph showing a change in the charging rate of the low-voltage battery while the vehicle is stopped.

Fig. 4 is a flowchart showing a detailed flow of the 1 st auxiliary charging time point setting process.

Fig. 5 is a flowchart showing a specific flow of the No. 2 auxiliary charging time point setting process.

Fig. 6 is a flowchart showing a specific flow of the auxiliary charging process.

Fig. 7 is a sequence diagram showing the flow of an interrupt process carried out in the case where the 1 st power-on operation by the user is carried out in the carrying out of the auxiliary charging process.

Fig. 8 is a sequence diagram showing the flow of an interrupt process carried out in the case where the 2 nd power-on operation by the user is carried out in the carrying out of the auxiliary charging process.

Fig. 9 is a timing chart showing the flow of interrupt processing executed in the case where external charging is performed in the execution of the auxiliary charging process.

Fig. 10 is a sequence diagram showing a flow of an interrupt process carried out in a case where a communication start operation by a user is carried out in the carrying out of the auxiliary charging process.

Fig. 11 is a sequence diagram showing a flow of an interrupt process executed in a case where a communication start operation by a user is performed in execution of the auxiliary charging process.

Fig. 12 is a flowchart showing a flow of an interrupt process in the case where the 1 st power-on operation by the user is performed or the case where the communication start operation is performed in the execution of the auxiliary charging process.

Detailed Description

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a diagram showing the configuration of a vehicle V mounted with a power supply system 1 according to the present embodiment.

The vehicle V includes drive wheels W and a power supply system 1, and the power supply system 1 transmits electric power between a drive motor M coupled to the drive wheels W and a high-voltage battery B1 described later. In the present embodiment, a case where the vehicle V is set as an electric vehicle that accelerates and decelerates mainly using power generated by the drive motor M will be described, but the present invention is not limited to this. The vehicle V may be a so-called hybrid vehicle equipped with a drive motor M as a power generation source and an engine.

The drive motor M is coupled to the drive wheels W via a power transmission mechanism not shown. When three-phase ac power is supplied from the power supply system 1 to the drive motor M, torque is generated in the drive motor M, and the torque is transmitted to the drive wheels W via a power transmission mechanism, not shown, to rotate the drive wheels W, thereby running the vehicle V. The drive motor M functions as a generator during deceleration of the vehicle V, generates regenerative electric power, and applies regenerative braking torque corresponding to the magnitude of the regenerative electric power to the drive wheels W. The regenerative electric power generated by the drive motor M is appropriately charged to the high-voltage battery B1 and the low-voltage battery B2 of the power supply system 1.

The power supply system 1 includes: a high-voltage circuit 2 provided with a high-voltage battery B1; a low-voltage circuit 3 provided with a low-voltage battery B2; a voltage converter 4 connecting the high-voltage circuit 2 and the low-voltage circuit 3; and an electronic control unit group 7 for controlling the high-voltage circuit 2, the low-voltage circuit 3, and the voltage converter 4.

High-voltage battery B1 is a secondary battery that can be charged or discharged to convert chemical energy into electrical energy, or can be charged to convert electrical energy into chemical energy. Hereinafter, a case will be described in which a so-called lithium ion battery that performs charge and discharge by lithium ion movement between electrodes is used as the high-voltage battery B1, but the present invention is not limited to this.

Low-voltage battery B2 is a secondary battery that can perform discharge for converting chemical energy into electrical energy and can perform charge for converting electrical energy into chemical energy. Hereinafter, a so-called lead storage battery in which lead dioxide is used for the positive electrode and spongy lead is used for the negative electrode and dilute sulfuric acid is used as the electrolyte will be described as the low-voltage storage battery B2, but the present invention is not limited thereto. In addition, the voltage of the low-voltage battery B2 is lower than the voltage of the high-voltage battery B1. Therefore, the voltage of the high-voltage circuit 2 is higher than the voltage of the low-voltage circuit 3.

The voltage converter 4 connects the high-voltage circuit 2 and the low-voltage circuit 3. The voltage converter 4 is a DCDC converter configured by combining a switching element, a reactor, a smoothing capacitor, and the like, and has a function of converting a voltage between the high-voltage circuit 2 and the low-voltage circuit 3. The voltage converter 4 turns on/off the driving switching element in accordance with a gate driving signal generated at a specific timing from a gate driving circuit, not shown, based on an instruction from the electronic control unit group 7, thereby stepping down the power in the high-voltage circuit 2 and supplying the power to the low-voltage circuit 3.

The high-voltage circuit 2 is connected to a power converter 21 and an in-vehicle charger 22.

The power converter 21 converts electric power between the high-voltage circuit 2 and the drive motor M. The power converter 21 is, for example, a PWM inverter using pulse width modulation, and has a function of converting direct-current power and alternating-current power. The power converter 21 is connected to the high-voltage circuit 2 on the dc input/output side thereof, and to the coils of the U-phase, V-phase, and W-phase of the drive motor M on the ac input/output side thereof. The power converter 21 turns on/off the switching elements of each phase from a gate drive circuit, not shown, in accordance with a gate drive signal generated at a specific timing based on an instruction from the electronic control unit group 7, thereby converting the direct-current power in the high-voltage circuit 2 into three-phase alternating-current power and supplying it to the drive motor M, or converting the three-phase alternating-current power supplied from the drive motor M into direct-current power and supplying it to the high-voltage circuit 2.

When the in-vehicle charger 22 is connected to, for example, a commercial household ac power supply, not shown, the ac power supplied from the ac power supply is converted into dc power and supplied to the high-voltage circuit 2, whereby the high-voltage battery B1 is charged. At this time, the voltage converter 4 is driven to reduce the voltage of the electric power in the high-voltage circuit 2 and supply the reduced voltage to the low-voltage circuit 3, whereby the low-voltage battery B2 may be charged. Hereinafter, the charging of high-voltage battery B1 via on-vehicle charger 22 is referred to as external charging.

The vehicle auxiliary machine 31 and the electronic control unit group 7 are connected to the low-voltage circuit 3. These vehicle auxiliary machines 31 and the electronic control unit group 7 operate by consuming electric power in the low-voltage circuit 3. The vehicle repairing machine 31 is composed of a plurality of electric components such as lamps, a car navigation system, audio equipment, and an air compressor.

Fig. 2 is a diagram showing the configuration of the electronic control unit group 7.

The electronic control unit group 7 includes a battery ECU70, a management ECU71, a vehicle body control module 72 (hereinafter referred to as "BCM 72"), and a telematics ECU 73. These battery ECU70, management ECU71, BCM72, and telematics ECU73 are connected to each other via a CAN bus 77, that is, a bus-type network that transmits various kinds of control information, and CAN transmit and receive necessary control information therebetween.

The management ECU71 is a microcomputer, and is mainly responsible for control relating to monitoring of the states of the high-voltage battery B1 and the low-voltage battery B2. The management ECU71 is connected to the high-voltage battery sensor 81 and the low-voltage battery sensor 82.

The high-voltage battery sensor 81 detects a physical quantity required for estimating the charging rate of the high-voltage battery B1 (the amount of charge of the battery expressed by a percentage) in the management ECU71, and transmits a signal corresponding to the detected value to the management ECU 71. More specifically, the high-voltage battery sensor 81 is constituted by a voltage sensor for detecting the terminal voltage of the high-voltage battery B1, a current sensor for detecting the current flowing through the high-voltage battery B1, a temperature sensor for detecting the temperature of the high-voltage battery B1, and the like. The management ECU71 calculates the charging rate of the high-voltage battery B1 according to a known algorithm based on the signal sent from the high-voltage battery sensor 81.

The low-voltage battery sensor 82 detects a physical quantity required for estimating the charging rate of the low-voltage battery B2 (the amount of charge of the battery expressed by a percentage) in the management ECU71, and transmits a signal corresponding to the detected value to the management ECU 71. More specifically, the low-voltage battery sensor 82 is constituted by a voltage sensor for detecting the terminal voltage of the low-voltage battery B2, a current sensor for detecting the current flowing through the low-voltage battery B2, a temperature sensor for detecting the temperature of the low-voltage battery B2, and the like. The management ECU71 calculates the charging rate of the low-voltage battery B2 according to a known algorithm based on the signal sent from the low-voltage battery sensor 82.

The BCM72 is a microcomputer and is responsible for control relating to reception of a vehicle start/stop operation, a door lock operation, a vehicle entry operation, and the like. The BCM72 is connected to a power switch 83 and a brake pedal 84 that can be operated by a user.

The BCM72 receives an on operation or an off operation by a user for starting or stopping the vehicle based on signals sent from these power switch 83 and brake pedal 84. The user can perform three operations, i.e., the 1 st on operation, the 2 nd on operation, and the off operation, by operating the power switch 83 and the brake pedal 84 in combination.

The 1 st on operation is an operation in which the user presses the power switch 83 when stepping on the brake pedal 84 in order to start the vehicle into the running mode. If the BCM72 accepts the 1 st turn-on operation by the user, the vehicle is activated into a travel mode and the vehicle is brought into a travelable state. The 2 nd on operation is an operation in which the user presses the power switch 83 without stepping on the brake pedal 84 in order to start the vehicle in the accessory mode. If the BCM72 accepts the 2 nd opening operation by the user, the vehicle is started to the accessory mode, and the state that the vehicle can be supplemented is formed. The off operation is an operation in which the user presses the power switch 83 to stop the vehicle. If the BCM72 accepts a shut down operation by the user, the vehicle is stopped.

The telematics ECU73 is a microcomputer, and is mainly responsible for control related to communication between portable terminals 85 (e.g., smartphones) that users have. Telematics ECU73 can communicate with portable terminal 85 outside the vehicle via communication module 74.

The telematics ECU73 receives a communication start operation of the portable terminal 85 by a user for starting the vehicle in a communication mode based on a signal transmitted from the communication module 74. If the telematics ECU73 accepts a communication start operation by the user, the vehicle is started in the communication mode. Thus, the user can acquire information of the vehicle (for example, the charging rate of the high-voltage battery B1), can set the charging schedule of the high-voltage battery B1, or can operate the air conditioner.

The battery ECU70 is a microcomputer mainly responsible for charge control of the low-voltage battery B2. The battery ECU70 includes a charge control unit 701, an auxiliary charging time setting unit 702, and a real time clock 704 (hereinafter referred to as "RTC 704").

The charge control unit 701 performs charge control for operating the voltage converter 4 to charge the low-voltage battery B2 with the electric power in the high-voltage circuit 2. The charge control unit 701 may selectively execute, as the charge control of the low-voltage battery B2, normal charge control in which the voltage converter 4 is operated while the vehicle is running, the electric power in the high-voltage circuit 2 is stepped down and supplied to the low-voltage circuit 3 to charge the low-voltage battery B2, and auxiliary charge control in which the voltage converter 4 is operated while the vehicle is stopped, the electric power in the high-voltage circuit 2 is stepped down and supplied to the low-voltage circuit 3 to charge the low-voltage battery B2.

During the running of the vehicle, the electric power output from the high-voltage battery B1 and the regenerative electric power output from the power converter 21 are supplied to the high-voltage circuit 2. Therefore, in the normal charge control, the low-voltage battery B2 can be charged with the electric power of the high-voltage battery B1 and the regenerative electric power. The charge control section 701 appropriately executes normal charge control so that the charging rate of the low-voltage battery B2 is maintained at a specific target charging rate during the start-up running mode of the vehicle.

On the other hand, when the vehicle is stopped and external charging by the in-vehicle charger 22 is not performed, only the electric power output from the high-voltage battery B1 is supplied to the high-voltage circuit 2. Therefore, in the auxiliary charging control, the low-voltage battery B2 can be charged with the electric power of the high-voltage battery B1.

Fig. 3 is a graph showing a change in the charging rate of the low-voltage battery B2 in the stop of the vehicle. Fig. 3 shows a case where the closing operation is performed by the user at time t 0. As shown in fig. 3, during the stop of the vehicle, the dark current constantly flows in the low-voltage battery B2, so that the charging rate thereof gradually decreases. Therefore, if the vehicle continues to stop for a long time, the charging rate of the low-voltage battery B2 will be lower than the specific start ensuring charging rate, and the vehicle may not start. Therefore, during the stop of the vehicle, the charge controller 701 executes the auxiliary charging control at the charging time set by the auxiliary charging time setting unit 702 (see times t1 and t3 in fig. 3) described later, and charges the low-voltage battery B2 with the electric power of the high-voltage battery B1. Thereby, the charging rate of the low-voltage battery B2 is prevented from falling below the start ensuring charging rate during the stop of the vehicle. A specific flow of the auxiliary charging process performed by the charging control unit 701 will be described in detail later with reference to fig. 6.

Returning to fig. 2, the auxiliary charging time setting unit 702 sets the auxiliary charging time, that is, the execution time (more specifically, the execution date and time) of the auxiliary charging control during the vehicle stop period from when the BCM72 receives the off operation to when the 1 st on operation is received, by executing the 1 st and 2 nd auxiliary charging time setting processes described later with reference to fig. 4 and 5. The auxiliary charging time setting unit 702 performs a 1 st auxiliary charging time setting process (see time t0 in fig. 3) described later in response to the BCM72 receiving the shutdown operation, and performs a 2 nd auxiliary charging time setting process (see time t3 in fig. 3) described later in response to the auxiliary charging control performed by the charging control unit 701 ending.

If the auxiliary charging time set by the auxiliary charging time setting unit 702 is reached during the vehicle stop period, the RTC704 activates the charging control unit 701, the auxiliary charging time setting unit 702, and the management ECU 71.

Fig. 4 is a flowchart showing a detailed flow of the 1 st auxiliary charging time point setting process. In response to BCM72 receiving the shutdown operation, assist charge time setting unit 702 executes the processing shown in fig. 4.

First, in S1, auxiliary charging time setting unit 702 obtains the current charging rate of high-voltage battery B1 from management ECU 71. Next, at S2, the auxiliary charging time setting unit 702 determines whether or not the acquired charging rate of the high-voltage battery B1 has not reached a specific auxiliary charging prohibition charging rate. If the determination result at S2 is "no", assist charging time setting unit 702 proceeds to S3.

Next, at S3, auxiliary charging time setting unit 702 obtains the current charging rate of low-voltage battery B2 from management ECU 71.

In S4, the auxiliary charging time setting unit 702 searches, for example, a predetermined auxiliary charging time determination map based on the acquired charging rate, and calculates a reserved activation time (see fig. 3), that is, a time from the present time to the next auxiliary charging time. According to the auxiliary charging time determination map, the reserved activation time is set to be longer as the charging rate is higher. In other words, the higher the charging rate, the later the next auxiliary charging timing. In addition, according to the assist charging time determination map, the reserved activation time is set such that the charging rate of the low-voltage battery B2 does not fall below the start guaranteed charging rate during the period from the present time to the next assist charging time, in consideration of the fact that the charging rate of the low-voltage battery B2 is reduced by dark current during the vehicle stop period. More specifically, the reserved activation time is set to a value obtained by adding a positive error margin to the start guarantee charging rate of the low-voltage battery B2 from the present time to the reserved activation time, based on the auxiliary charging time determination map.

In S5, the auxiliary charging time setting unit 702 sets the next auxiliary charging time based on the calculated reserved activation time, and ends the processing shown in fig. 4. More specifically, the auxiliary charging time setting unit 702 calculates the next auxiliary charging time (refer to time t1 in fig. 3) by adding the current date and time to the reserved activation time, and transmits the calculated time to the RTC 704. After that, if the set auxiliary charging time is reached, the RTC704 starts the charging control section 701 to execute auxiliary charging control.

If the determination result at S2 is yes, that is, if the charging rate of the high-voltage battery B1 does not reach the auxiliary charging prohibition charging rate, the auxiliary charging time setting unit 702 does not set the next auxiliary charging time and ends the processing shown in fig. 4. Therefore, after that, the RTC704 does not activate the charging control section 701. That is, the charge control unit 701 does not perform the auxiliary charging control when the charging rate of the high-voltage battery B1 does not reach the auxiliary charging prohibition charging rate.

Fig. 5 is a flowchart showing a specific flow of the No. 2 auxiliary charging time point setting process. In response to the end of the auxiliary charging control performed by charging control unit 701 during the stop of the vehicle, auxiliary charging time setting unit 702 executes the processing shown in fig. 5.

First, in S11, auxiliary charging time setting unit 702 obtains the current charging rate of high-voltage battery B1 from management ECU 71. Next, at S12, the auxiliary charging time setting unit 702 determines whether or not the acquired charging rate of the high-voltage battery B1 has not reached the auxiliary charging prohibition charging rate. If the determination result at S12 is "no", assist charging time setting unit 702 proceeds to S13.

Next, at S13, the auxiliary charging time setting unit 702 acquires the next scheduled activation time from the charging control unit 701 (see S28, S31, S32, and the like in fig. 6, which will be described later). Next, at S14, the auxiliary charging time setting unit 702 calculates the scheduled engine stop time by summing the time elapsed since the BCM72 received the closing operation and the current time and the scheduled activation time acquired at S13. Here, the engine stop time is the time elapsed since the BCM72 received the closing operation. Therefore, the predetermined engine stop time refers to the engine stop time from the present to the scheduled start time.

Next, in S15, assist charge time setting unit 702 determines whether or not the scheduled engine stop time calculated in S14 has not reached a scheduled assist charge allowable period (for example, several tens of days). If the determination result at S15 is yes, auxiliary charging time setting unit 702 proceeds to S16.

In S16, the auxiliary charging time setting unit 702 sets the next auxiliary charging time based on the reserved activation time acquired in S13, and ends the processing shown in fig. 5. More specifically, the auxiliary charging time setting unit 702 calculates the next auxiliary charging time (refer to time t3 in fig. 3) by adding the current date and time to the reserved activation time, and transmits the calculated time to the RTC 704. After that, if the set auxiliary charging time is reached, the RTC704 starts the charging control section 701 to execute auxiliary charging control. That is, when the engine stop time does not reach the auxiliary charging allowable period, the charging control unit 701 executes the auxiliary charging control at the auxiliary charging time set by the auxiliary charging time setting unit 702.

On the other hand, if the determination result at S15 is "no", the auxiliary charging time setting unit 702 does not set the next auxiliary charging time, but ends the processing shown in fig. 5. Therefore, after that, the RTC704 does not activate the charging control section 701. That is, when the engine stop time is longer than the auxiliary charging allowable period, the charging control unit 701 does not perform the auxiliary charging control. Therefore, the assist charge control is permitted to be executed during the period from when the BCM72 receives the shutdown operation to when the assist charge permission period elapses. Further, after the BCM72 receives the shutdown operation and the sub-charging permission period elapses, a sub-charging prohibition period (see fig. 3) is formed in which the execution of the sub-charging control is prohibited. If the determination result at S12 is yes, that is, if the charging rate of high-voltage battery B1 does not reach the auxiliary charging prohibition charging rate, auxiliary charging time setting unit 702 does not set the next auxiliary charging time, and the process shown in fig. 4 is ended.

Fig. 6 is a flowchart showing a specific flow of the auxiliary charging process. In response to being activated by the RTC704 during the vehicle stop period, the charging control section 701 executes the processing shown in fig. 6.

First, in S21, the charge controller 701 acquires the current charging rate of the high-voltage battery B1 from the management ECU 71. Next, in S22, the charge control unit 701 determines whether the acquired charging rate of the high-voltage battery B1 has not reached the auxiliary charging prohibition charging rate. If the determination result of S22 is yes, charging control unit 701 immediately ends the processing shown in fig. 6. That is, in the case where the charging rate of the high-voltage battery B1 does not reach the auxiliary charging prohibition charging rate, the charging control section 701 does not perform the auxiliary charging control (refer to S27), but ends the processing shown in fig. 6. If the determination result at S22 is "no", that is, if the charging rate of the high-voltage battery B1 is equal to or higher than the auxiliary charging prohibition charging rate, the charging control unit 701 proceeds to S23.

Next, in S23, the charging control unit 701 starts counting the charging duration time corresponding to the time elapsed after the start of the sub-charging control. Next, at S24, charge controller 701 obtains the current charging rate of low-voltage battery B2 from management ECU 71.

Next, in S25, charge control unit 701 determines whether or not the charge duration is equal to or longer than a predetermined upper limit time (for example, several hours). If the determination result at S25 is "no", the charge control unit 701 proceeds to S26.

In S26, the charge control unit 701 determines whether or not the charging rate of the low-voltage battery B2 acquired in S24 is equal to or higher than the target charging rate. If the determination result at S26 is "no", the charge control unit 701 proceeds to S27. In S27, charge control unit 701 executes the auxiliary charging control, and returns to S24. More specifically, the charge control unit 701 operates the voltage converter 4 to reduce the voltage of the electric power supplied from the high-voltage battery B1 to the high-voltage circuit 2 and supply the reduced voltage to the low-voltage circuit 3, thereby charging the low-voltage battery B2.

If the determination result at S26 is yes, that is, if the charging rate of the low-voltage battery B2 exceeds the target charging rate, the charge control unit 701 proceeds to S28. At S28, the charge control unit 701 searches the auxiliary charging timing determination map based on the charging rate of the low-voltage battery B2, calculates the next scheduled starting time, and then ends the processing shown in fig. 6.

If the determination result at S25 is yes, that is, if the auxiliary charging duration exceeds the upper limit time before the charging rate of the low-voltage battery B2 exceeds the target charging rate, the charging control unit 701 proceeds to S29. At S29, the charge control unit 701 searches the auxiliary charging timing determination map based on the charging rate of the low-voltage battery B2 to calculate a provisional value for the next scheduled starting time.

In S30, charge control unit 701 determines whether or not the provisional value of the reserved activation time calculated in S29 is equal to or greater than a predetermined fixed time. If the determination result at S30 is yes, the charge control unit 701 proceeds to S31, and if the determination result at S30 is no, the process proceeds to S32. At S31, charge control unit 701 calculates a provisional value calculated based on the charging rate of low-voltage battery B2 as the reserved activation time, and then ends the processing shown in fig. 6. In S32, charging control unit 701 calculates a predetermined fixed time as the reserved activation time, and then ends the processing shown in fig. 6.

As described above, in S30 to S32, when the charging duration exceeds the upper limit time and the sub-charging control is terminated, the charging control unit 701 calculates the longer of the provisional value calculated based on the charging rate of the low-voltage battery B2 and the predetermined fixed time as the reserved activation time. As described above, in S16 of the 2 nd auxiliary charging time point setting process shown in fig. 5, the next auxiliary charging time point is set by adding the current date and time to the reserved activation time calculated in the auxiliary charging process of fig. 6. Therefore, when the charging duration time exceeds the upper limit time and the auxiliary charging control is ended, auxiliary charging time setting unit 702 sets the later one of the time calculated based on the charging rate of low-voltage battery VB2 at that time and the predetermined time as the auxiliary charging time.

Next, the flow of interrupt processing in the case where the user operates the vehicle or the mobile terminal while the auxiliary charging process shown in fig. 6 is executed during the vehicle stop period will be described with reference to the time charts of fig. 7 to 11 and the flowchart of fig. 12.

Fig. 7 is a sequence diagram showing the flow of an interrupt process carried out in the case where the 1 st power-on operation by the user is carried out in the carrying out of the auxiliary charging process. Fig. 7 shows a case where the charging control section 701, which is activated by the RTC704 at time t11 after the BCM72 receives the closing operation by the user at time t10, starts the auxiliary charging control shown in fig. 6.

First, if the auxiliary charging control is started at time t11, the charging rate of the low-voltage battery B2 is slowly increased by the electric power supplied from the high-voltage battery B1. As shown in fig. 7, when BCM72 receives the 1 st turn-on operation by the user while the sub-charging control is being executed (refer to time t12), charging control unit 701 shifts from the sub-charging control to the normal charging control while keeping voltage converter 4 operating. As described above, in the normal charge control, the electric power output from the high-voltage battery B1 and the regenerative electric power are appropriately supplied so that the charging rate of the low-voltage battery B2 is maintained at the target charging rate. Therefore, after time t12, the charging rate of the low-voltage battery B2 does not fluctuate and gradually increases toward the target charging rate.

Thereafter, at time t13, in response to BCM72 receiving the closing operation by the user, assist charge time setting unit 702 executes the 1 st assist charge time setting process shown in fig. 4. Thus, the next auxiliary charging time is set to time t14 based on the charging rate of the low-voltage battery B2 at time t13 at which the closing operation is received.

Fig. 8 is a sequence diagram showing the flow of an interrupt process carried out in the case where the 2 nd power-on operation by the user is carried out in the carrying out of the auxiliary charging process. Fig. 8 shows a case where the charging control section 701, which is activated by the RTC704 at time t21 after the BMC72 receives the off operation by the user at time t20, starts the auxiliary charging control shown in fig. 6.

First, if the auxiliary charging control is started at time t21, the charging rate of the low-voltage battery B2 is slowly increased by the electric power supplied from the high-voltage battery B1. As shown in fig. 8, when BCM72 receives the 2 nd turn-on operation by the user while the auxiliary charging control is being executed (refer to time t22), charging control unit 701 stops voltage converter 4 and ends the auxiliary charging control being executed. In addition, if the BCM72 accepts the 2 nd turn-on operation, the vehicle is started to the accessory mode, and therefore, the user can utilize the vehicle patch 31 using the electric power supplied from the low-voltage battery B2. Therefore, after time t22, the charging rate of low-voltage battery B2 gradually decreases.

Thereafter, at time t23, in response to BCM72 receiving the closing operation by the user, assist charge time setting unit 702 executes the 1 st assist charge time setting process shown in fig. 4. Thus, the next auxiliary charging time is set to time t24 based on the charging rate of the low-voltage battery B2 at time t23 at which the closing operation is received.

Fig. 9 is a timing chart showing the flow of interrupt processing executed in the case where external charging is performed in the execution of the auxiliary charging process. Fig. 9 shows a case where the charging control section 701, which is activated by the RTC704 at time t31 after the BMC72 receives the off operation by the user at time t30, starts the auxiliary charging control shown in fig. 6.

First, if the auxiliary charging control is started at time t31, the charging rate of the low-voltage battery B2 is slowly increased by the electric power supplied from the high-voltage battery B1. As shown in fig. 9, when the external charging is started while the auxiliary charging control is being executed (refer to time t32), the charging control unit 701 continues the auxiliary charging control while keeping the voltage converter 4 operating. More specifically, the charging control section 701 continues the auxiliary charging control until the charging rate of the low-voltage battery B2 reaches the target charging rate (refer to S26 of fig. 6). Thus, after time t32, high-voltage battery B1 is charged with electric power supplied from in-vehicle charger 22 to high-voltage circuit 2, and low-voltage battery B2 is also charged. Even when the charging of the high-voltage battery B1 at time t33 is completed, the charging control unit 701 continues the auxiliary charging control when the charging rate of the low-voltage battery B2 does not reach the target charging rate at this point in time.

When the charging rate of the low-voltage battery B2 at time t34 reaches the target charging rate, the charge control unit 701 calculates a scheduled activation time based on the charging rate of the low-voltage battery B2 at that time (see S28 in fig. 6), and the auxiliary charging time setting unit 702 sets the next auxiliary charging time to time t35 based on the scheduled activation time.

Fig. 10 is a sequence diagram showing a flow of an interrupt process carried out in a case where a communication start operation by a user is carried out in the carrying out of the auxiliary charging process. Fig. 10 shows a case where the charging control section 701, which is activated by the RTC704 at time t41 after the BMC72 receives the off operation by the user at time t40, starts the auxiliary charging control shown in fig. 6.

First, if the auxiliary charging control is started at time t41, the charging rate of the low-voltage battery B2 is slowly increased by the electric power supplied from the high-voltage battery B1. As shown in fig. 10, when telematics ECU73 receives a communication start operation by a user while the auxiliary charging control is being executed (refer to time t42), charging control unit 701 stops voltage converter 4 and ends the auxiliary charging control being executed. As described above, if the telematics ECU73 accepts a communication start operation by the user, the vehicle is started in the communication mode. Therefore, after time t42, the charging rate of low-voltage battery B2 gradually decreases.

Thereafter, at time t43, in response to telematics ECU73 receiving the communication end operation by the user, auxiliary charging time setting unit 702 executes the 1 st auxiliary charging time setting process shown in fig. 4. Thus, the next auxiliary charging time is set to time t44 based on the charging rate of the low-voltage battery B2 at time t43 at which the communication end operation is received.

Fig. 11 is a sequence diagram showing a flow of an interrupt process executed in a case where a communication start operation by a user is performed in execution of the auxiliary charging process. Further, after time t52, the timing chart of fig. 11 differs.

As shown in fig. 11, when telematics ECU73 receives a communication start operation by a user while the auxiliary charging control is being executed (refer to time t52), charging control unit 701 stops voltage converter 4 and ends the auxiliary charging control being executed. Thereafter, the charging rate of the low-voltage battery B2 is gradually decreased, and at time t53, the charging rate of the low-voltage battery B2 is decreased to the start guarantee charging rate. After the auxiliary charging control is ended in response to the acceptance of the communication start operation, as shown in fig. 11, in the case where the charging rate of the low-voltage battery B2 does not reach the start guaranteed charging rate (refer to time t53), the charging control section 701 restarts the auxiliary charging control. More specifically, the auxiliary charging control is continued until the charging rate of the low-voltage battery B2 reaches the target charging rate. Therefore, at time t54, after telematics ECU73 receives the communication end operation by the user, charging control unit 701 continues to perform the auxiliary charging control.

When the charging rate of the low-voltage battery B2 at time t55 reaches the target charging rate, the charge control unit 701 calculates a scheduled activation time based on the charging rate of the low-voltage battery B2 at that time (see S28 in fig. 6), and the auxiliary charging time setting unit 702 sets the next auxiliary charging time to time t56 based on the scheduled activation time.

Fig. 12 is a flowchart showing a flow of an interrupt process in the case where the 1 st power-on operation by the user is performed or the case where the communication start operation is performed in the execution of the auxiliary charging process. While the auxiliary charging process shown in fig. 6 is being executed, the process shown in fig. 12 is repeatedly executed in the charging control unit 701 at a specific cycle.

First, in S41, charge controller 701 determines whether or not BMC72 accepts the 1 st power-on operation by the user. If the determination result at S41 is yes, the charge control unit 701 proceeds to S42, and if no, proceeds to S43. In S42, when the voltage converter 4 is kept operating, the charging control unit 701 shifts from the auxiliary charging control to the normal charging control, and then ends the processing shown in fig. 12.

In S43, charge control unit 701 determines whether or not telematics ECU73 has accepted the communication start operation by the user. If the determination result at S43 is "no", the charge control unit 701 proceeds to S44, and if yes, it proceeds to S45. In S44, the charge control unit 701 continues the auxiliary charging control being executed, and ends the processing shown in fig. 12.

In S45, the charge control unit 701 stops the voltage converter 4 and ends the auxiliary charge control during execution. At S46, charge control unit 701 determines whether or not telematics ECU73 has accepted the communication end operation by the user. If the determination result at S46 is "no", the charge control unit 701 returns to S46, and if yes, the process proceeds to S47.

At S47, the charge control unit 701 determines whether the charging rate of the low-voltage battery B2 has not reached the start guaranteed charging rate. If the determination result in S47 is yes, the charging control unit 701 resumes the auxiliary charging control and ends the processing shown in fig. 12. In S48, the charge control unit 701 determines the next auxiliary charging time based on the current charging rate of the low-voltage battery B2, transmits a command signal to the auxiliary charging time setting unit 702, performs the 1 st auxiliary charging time setting process shown in fig. 4, and then ends the process shown in fig. 12.

According to the power supply system 1 of the present embodiment, the following effects are obtained.

(1) The auxiliary charging time setting unit 702 sets an auxiliary charging time, which is a time period for executing the auxiliary charging control during a vehicle stop period from when the user performs the off operation to when the 1 st on operation is received. Further, when the engine stop time, that is, the time elapsed since the shutdown operation was received, does not reach the specific auxiliary charging permission period, the charging control unit 701 executes auxiliary charging control at the auxiliary charging time set by the auxiliary charging time setting unit 702. This prevents the charging rate of low-voltage battery B2 from decreasing excessively while vehicle V is stopped. In addition, when the engine stop time is longer than the auxiliary charging allowable period, the charging control unit 701 does not perform the auxiliary charging control. This prevents the charging rate of the high-voltage battery B1 from being significantly reduced by repeating the auxiliary charging control during a long-time stop of the vehicle V that exceeds the auxiliary charging allowable period.

(2) For example, when low-voltage battery B2 is in a low-temperature environment, the charging efficiency is lower than when it is in a normal-temperature environment. Therefore, if it is desired to continue the auxiliary charging control in a low-temperature environment until the charging rate of the low-voltage battery B2 reaches the target charging rate, the charging time may be extended, and the power consumption of the high-voltage battery B1 further accompanying the auxiliary charging control may be increased. In contrast, the charging control unit 701 ends the assist charging control when the charging rate of the low-voltage battery B2 after the start of the assist charging control exceeds the target charging rate, or when the charging duration, that is, the elapsed time since the start of the assist charging control, exceeds the upper limit time. Thereby, it is possible to prevent the charging rate of the high-voltage battery B1 in a low-temperature environment from unexpectedly decreasing significantly due to the auxiliary charging control.

(3) The auxiliary charging time setting unit 702 sets the next auxiliary charging time after the auxiliary charging control is completed, and sets the later of the time and the predetermined time calculated based on the charging rate of the low-voltage battery B2 as the auxiliary charging time when the charging duration exceeds the upper limit time and the auxiliary charging control is completed. Thereby, it is possible to prevent the charging rate of the high-voltage battery B1 from being significantly reduced due to the repeated execution of the auxiliary charging control at a high frequency in a low-temperature environment such as a charging duration exceeding an upper limit time.

(4) When the 1 st on operation for starting the running mode of the vehicle V is received while the auxiliary charging control is being executed, the charging control unit 701 shifts from the auxiliary charging control being executed to the normal charging control. Thus, low-voltage battery B2 can be continuously charged without disturbing the interrupt operation by the user.

(5) When the charge control unit 701 receives the 2 nd on operation for starting the vehicle to the accessory mode while the auxiliary charge control is being executed, the auxiliary charge control is terminated. This prevents the auxiliary charging control being performed from giving excessive priority to the use of the vehicle auxiliary device 31 by the user.

(6) When receiving a communication start operation of portable terminal 85 by the user while the auxiliary charging control is being executed, charging control unit 701 ends the auxiliary charging control. This prevents the user from being hindered in operating the portable terminal 85 because the auxiliary charging control is performed with too high priority.

(7) The auxiliary charging time setting unit 702 sets the auxiliary charging time at which the charging control unit 701 performs the auxiliary charging control during the vehicle stop period from the time when the user performs the off operation to the time when the 1 st on operation is received, and the management ECU71 acquires the charging rate of the high-voltage battery B1. When the charging rate of the high-voltage battery B1 is higher than the auxiliary charging prohibition charging rate, the charging control unit 701 performs auxiliary charging control at the auxiliary charging time set by the auxiliary charging time setting unit 702. This prevents the charging rate of low-voltage battery B2 from decreasing excessively while vehicle V is stopped. In addition, the charge control unit 701 does not perform the auxiliary charging control when the charging rate of the high-voltage battery B1 does not reach the auxiliary charging prohibition charging rate. This prevents the charging rate of the high-voltage battery B1 from decreasing below the auxiliary charging prohibition charging rate by repeating the auxiliary charging control while the vehicle V is stopped.

While one embodiment of the present invention has been described above, the present invention is not limited to this. The detailed configuration may be appropriately modified within the scope of the present invention.

Reference numerals

V vehicle

1 power supply system

2 high-voltage circuit

B1 high-voltage accumulator (high-voltage accumulator)

3 low voltage circuit

B2 Low-voltage accumulator (Low-voltage accumulator)

31 vehicle repairing machine

4 Voltage converter (charging circuit)

7 electronic control unit group

70 battery ECU

701 charging control part (charging control scheme)

Setting part of auxiliary charging time point 702 (time point setting scheme)

704RTC

71 management ECU (residual acquisition scheme)

72BCM (operation acceptance scheme)

73 remote information processing ECU (communication scheme)

74 communication module (communication scheme)

81 high-voltage accumulator sensor (residual acquisition scheme)

82 low-voltage battery sensor

83 Power switch (operation acceptance scheme)

84 brake pedal (operation acceptance scheme)

85 portable terminal