JP2020150784A - Power system - Google Patents

Abstract

To provide a power system which can correctly charge under different input voltages of an external charger.SOLUTION: A charging switchover unit 40 is a relay which can switch over to either a series circuit which connects a first high voltage battery 11 and a second high voltage battery 12 in series, or a parallel circuit which connects the first high voltage battery 11 and the second high voltage battery 12 in parallel. When an input voltage is a first voltage (for example, approximately 400 V), a control unit 50 controls the charging switchover unit 40 to form the parallel circuit to charge power, supplied from a quick charger 2, to the first high voltage battery 11 and the second high voltage battery 12. When an input voltage is a second voltage (for example, approximately 800 V) higher than the first voltage (for example, approximately 400 V), the control unit controls the charging switchover unit 40 to form the series circuit to charge the first high voltage battery 11 and the second high voltage battery 12 with power supplied from a super quick charger 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply system.

Conventionally, as a power supply system, for example, Patent Document 1 discloses a quick charging device for a vehicle that charges electric power supplied from an external charger. This quick charging device is equipped with multiple battery modules, and the charging time is shortened by connecting multiple battery modules in series during charging and connecting multiple battery modules in parallel during discharging. There is.

JP-A-2018-32363

By the way, the quick charging device described in Patent Document 1 described above includes, for example, an external charger for quick charging and an external charger for ultra-rapid charging having an input voltage higher than that of the external charger for quick charging. It is desired that both external chargers can be used for charging.

Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a power supply system capable of appropriately charging when the input voltage of an external charger is different.

In order to solve the above-mentioned problems and achieve the object, the power supply system according to the present invention includes a first battery mounted on the vehicle and capable of storing power, and a second battery mounted on the vehicle and capable of storing power. , A switching unit capable of switching to a series circuit connecting the first battery and the second battery in series, or a parallel circuit connecting the first battery and the second battery in parallel, and a first external charger. It includes a first input unit that is connected and inputs power supplied from the first external charger, and a control unit that controls the switching unit based on the input voltage of the power input from the first input unit. When the input voltage is the first voltage, the control unit controls the switching unit to form the parallel circuit, and supplies power supplied from the first external charger to the first battery and the second battery. When the battery is charged and the input voltage is a second voltage higher than the first voltage, the switching unit is controlled to form the series circuit, and the power supplied from the first external charger is used for the first battery and the first battery. It is characterized by charging the second battery.

In the power supply system, the switching unit includes a switch for series connection forming the series circuit, a first switch for parallel connection forming the parallel circuit, and a second switch for parallel connection forming the parallel circuit. The series circuit includes a switch, in which the positive electrode of the first input unit and the positive electrode of the first battery are connected, and the negative electrode of the first battery and the positive electrode of the second battery are the switches for connecting in series. The negative voltage of the second battery and the negative voltage of the first input unit are connected to the parallel circuit, and the positive voltage of the first input unit and the positive voltage of the first battery are connected in the parallel circuit. The negative voltage of the battery and the negative voltage of the first input unit are connected via the first switch for the parallel connection, and further, the positive voltage of the first input unit and the positive voltage of the second battery are the second for the parallel connection. Connected via a switch, the negative electrode of the second battery and the negative electrode of the first input unit are connected, and when the input voltage is the first voltage, the control unit is connected to the first switch for parallel connection and the first switch for parallel connection. When the second switch for parallel connection is turned on and the switch for series connection is turned off to form the parallel circuit and the input voltage is the second voltage, the switch for series connection is turned on and It is preferable to turn off the first switch for parallel connection and the second switch for parallel connection to form the series circuit.

In the power supply system, the voltage applied to the series circuit by the first battery and the second battery, the voltage applied to the parallel circuit by the first battery, and the voltage applied to the parallel circuit by the second battery. The circuit voltage detection unit that can detect the voltage, the first battery voltage detection unit that can detect the voltage between the positive and negative sides of the first battery, and the voltage between the positive and negative sides of the second battery. Further including a possible second battery voltage detection unit, the control unit transfers power from the first external charger to the first input unit after connecting the first external charger to the first input unit. Before supplying, the switch for series connection and the first switch for parallel connection are based on the detection results of the circuit voltage detection unit, the first battery voltage detection unit, and the second battery voltage detection unit. , And it is preferable to detect the failure of the second switch for parallel connection.

In the power supply system, the control unit includes the voltages of the first battery and the second battery detected by the circuit voltage detection unit, the voltage of the first battery detected by the first battery voltage detection unit, and the voltage of the first battery. , The failure of the switch for series connection is detected based on the voltage of the second battery detected by the second battery voltage detection unit, the voltage of the first battery detected by the circuit voltage detection unit, and , The failure of the first switch for parallel connection is detected based on the voltage of the first battery detected by the first battery voltage detection unit, and the voltage of the second battery detected by the circuit voltage detection unit. , And it is preferable to detect the failure of the second switch for parallel connection based on the voltage of the second battery detected by the second battery voltage detection unit.

In the power supply system, the first battery and the second battery are connected by the series circuit or the parallel circuit to form a power storage unit, and are provided on the rear side in the total length direction of the vehicle, and the power storage unit and the power storage unit are provided. A rear power supply box that turns on and off the electrical connection with the load unit on the rear side of the vehicle, and electricity between the power storage unit and the load unit on the front side of the vehicle provided on the front side in the total length direction of the vehicle. It is preferable that one of the rear power supply box and the front power supply box includes a front power supply box for turning on and off the connection, and turns on and off the electrical connection between the first input unit and the power storage unit.

In the power supply system, the rear power supply box includes a second input unit connected to a second external charger having a charging voltage lower than that of the first external charger and inputting power supplied from the second external charger. And the other of the front power supply box preferably turns on and off the electrical connection between the second input unit and the power storage unit.

In the power supply system, the switching unit is provided between the positive voltage of the first battery and the positive voltage of the second battery, and is an electrical connection between the positive voltage of the first battery and the positive voltage of the second battery. The control unit includes a switch for voltage equalization that turns on and off the voltage, and a resistor connected in parallel to the switch for voltage equalization, and the control unit equalizes the voltages of the first battery and the second battery. In this case, the switch for voltage equalization is turned off to form a closed circuit connecting the positive electrode of the first battery and the positive electrode of the second battery via the resistor, and the positive electrode of the first battery and the second battery are formed. It is preferable that a current flows through the resistor from the high potential side to the low potential side in the positive electrode of the battery.

The power supply system includes a shutoff switch capable of shutting off the first battery and the second battery, and the control unit controls the shutoff switch when the first battery is abnormal. When the first battery is shut off and power is supplied from the second battery to the load portion on the rear side of the vehicle and the load portion on the front side of the vehicle, and the second battery is abnormal, the switch for shutting off. It is preferable to control the above to shut off the second battery and supply electric power from the first battery to the load portion on the rear side of the vehicle and the load portion on the front side of the vehicle.

In the power supply system, when the control unit supplies power to the first load unit whose load voltage is the first voltage, the control unit controls the switching unit to form the parallel circuit to form the first battery and the first load unit. 2 When power is supplied from the battery to the first load unit and power is supplied to the second load unit whose load voltage is the second voltage, the switching unit is controlled to form the series circuit and the first load unit is formed. It is preferable to supply electric power from the battery and the second battery to the second load unit.

The power supply system includes a plurality of battery units having the first battery, the second battery, the switching unit, the first input unit, and the control unit, and the plurality of battery units are connected in series. Then, in each of the battery units, when the input voltage is the first voltage, the control unit controls the switching unit to form the parallel circuit and receives the power supplied from the first external charger. When the first battery and the second battery are charged and the input voltage is the second voltage, the switching unit is controlled to form the series circuit, and the power supplied from the first external charger is used. It is preferable to charge the first battery and the second battery.

In the power supply system, the switching unit includes a first switch for constant current that adjusts the current flowing from the first battery to the second battery when the parallel circuit is formed, and the first switch from the second battery to the second battery. It is preferable that the battery includes a second switch for a constant current that adjusts the current flowing through the battery.

In the power supply system, the control unit controls the switching unit to form the series circuit, and supplies electric power from the first battery and the second battery to the second load unit whose load voltage is the second voltage. It is preferable to supply power from either the first battery or the second battery to the first load unit whose load voltage is the first voltage.

The power supply system according to the present invention can be appropriately charged when the input voltage of the external charger is different by switching the first battery and the second battery to a series circuit or a parallel circuit.

FIG. 1 is a circuit diagram showing a configuration example of a power supply system according to the first embodiment. FIG. 2 is a circuit diagram showing an operation example of the power supply system at the time of quick charging according to the first embodiment. FIG. 3 is a circuit diagram showing an operation example of the power supply system at the time of ultra-rapid charging according to the first embodiment. FIG. 4 is a diagram showing a list of ON / OFF of each relay according to the first embodiment. FIG. 5 is a flowchart showing an operation example of the power supply system according to the first embodiment. FIG. 6 is a circuit diagram showing an example of detecting an on-stick failure of the charging relay according to the first embodiment. FIG. 7 is a circuit diagram showing an example of detecting an off-stick failure of the charging relay according to the first embodiment. FIG. 8 is a circuit diagram showing an example of detecting an off-stick failure of the charging relay according to the first embodiment. FIG. 9 is a circuit diagram showing an example of detecting an off-stick failure of the charging relay according to the first embodiment. FIG. 10 is a flowchart showing an example of detecting a failure of the charging relay according to the first embodiment. FIG. 11 is a circuit diagram showing a configuration example of the power supply system according to the second embodiment. FIG. 12 is a circuit diagram showing an operation example of the power supply system according to the second embodiment when the vehicle is running. FIG. 13 is a circuit diagram showing an operation example of the power supply system according to the second embodiment during rapid charging. FIG. 14 is a circuit diagram showing an operation example of the power supply system according to the second embodiment at the time of ultra-rapid charging. FIG. 15 is a circuit diagram showing an operation example at the time of front precharging of the power supply system according to the second embodiment. FIG. 16 is a circuit diagram showing an operation example at the time of reapply charging of the power supply system according to the second embodiment. FIG. 17 is a circuit diagram showing an operation example at the time of battery equalization processing of the power supply system according to the second embodiment. FIG. 18 is a flowchart showing an operation example at the time of battery equalization processing of the power supply system according to the second embodiment. FIG. 19 is a circuit diagram showing an operation example when the battery of the power supply system according to the second embodiment is abnormal. FIG. 20 is a diagram showing a list of each relay ON / OFF according to the second embodiment. FIG. 21 is a flowchart showing an operation example when the battery of the power supply system according to the second embodiment is abnormal. FIG. 22 is a circuit diagram showing a configuration example of the power supply system according to the third embodiment. FIG. 23 is a circuit diagram showing an operation example (No. 1) of the power supply system according to the third embodiment when the vehicle is running. FIG. 24 is a circuit diagram showing an operation example (No. 2) of the power supply system according to the third embodiment when the vehicle is running. FIG. 25 is a circuit diagram showing an operation example (No. 3) of the power supply system according to the third embodiment when the vehicle is running. FIG. 26 is a circuit diagram showing an operation example of the power supply system according to the third embodiment at the time of ultra-rapid charging. FIG. 27 is a circuit diagram showing an operation example (No. 1) of the power supply system according to the third embodiment during rapid charging. FIG. 28 is a circuit diagram showing an operation example (No. 2) of the power supply system according to the third embodiment during rapid charging. FIG. 29 is a flowchart showing an operation example at the time of quick charging of the power supply system according to the third embodiment. FIG. 30 is a diagram showing a list of ON / OFF of each relay according to the third embodiment. FIG. 31 is a circuit diagram showing the diode operation of the FET according to the third embodiment. FIG. 32 is a diagram showing the diode operation of the FET according to the third embodiment. FIG. 33 is a circuit diagram showing a charge rate equalization process according to the third embodiment. FIG. 34 is a circuit diagram showing a configuration example of the constant current circuit according to the third embodiment. FIG. 35 is a sequence chart showing the charge rate equalization processing according to the third embodiment. FIG. 36 is a perspective view showing a configuration example of the battery unit according to the fourth embodiment. FIG. 37 is a circuit diagram showing a configuration example of the battery unit according to the fourth embodiment. FIG. 38 is a block diagram showing a configuration example of the power supply system according to the fourth embodiment. FIG. 39 is a schematic view showing a configuration example of the battery unit according to the fourth embodiment. FIG. 40 is a schematic view showing overcurrent suppression (No. 1) at the time of parallel connection according to the fourth embodiment. FIG. 41 is a schematic view showing overcurrent suppression (No. 2) at the time of parallel connection according to the fourth embodiment. FIG. 42 is a flowchart showing overcurrent suppression at the time of parallel connection according to the fourth embodiment. FIG. 43 is a schematic view showing an operation example at the time of battery failure according to the fourth embodiment. FIG. 44 is a flowchart showing an operation example at the time of battery failure according to the fourth embodiment.

The embodiment (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Further, the configurations described below can be combined as appropriate. In addition, various omissions, substitutions or changes of the configuration can be made without departing from the gist of the present invention.

[First Embodiment]
The power supply system 1 according to the first embodiment will be described with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration example of the power supply system 1 according to the first embodiment. FIG. 2 is a circuit diagram showing an operation example of the power supply system 1 at the time of quick charging according to the first embodiment. FIG. 3 is a circuit diagram showing an operation example of the power supply system 1 at the time of ultra-rapid charging according to the first embodiment. FIG. 4 is a diagram showing a list of ON / OFF of each relay according to the first embodiment.

The power supply system 1 is mounted on the vehicle 100 and supplies electric power to the load unit. The power supply system 1 is mounted on, for example, an electric vehicle such as an EV (Electric Vehicle), a HEV (Hybrid Electric Vehicle), or a PHEV (Plug-in Hybrid Electric Vehicle). The power supply system 1 charges the electric power supplied by the external charger and supplies the charged electric power to the load unit. The power supply system 1 charges, for example, the electric power supplied by the quick charger 2 or the ultra-rapid charger 3 as an external charger, and supplies the charged electric power to the rear motor 5A via the rear inverter 4A as a load unit. .. Here, the output voltage of the quick charger 2 is, for example, about 400 V. The ultra-quick charger 3 has a higher output voltage than the quick charger 2, for example, the output voltage is about 800 V. The quick charger 2 and the ultra-quick charger 3 are installed in a charging station or the like of the vehicle 100, and supply electric power to the power supply system 1 by attaching the connector C to the DC charging port 20A of the power supply system 1. Hereinafter, the power supply system 1 will be described in detail.

The power supply system 1 includes a power storage unit 10, a DC charging port 20A as a first input unit, a rear power supply box 30A, a charging switching unit 40 as a switching unit, and a control unit 50. The power storage unit 10 stores electric power, and has a first high voltage battery 11 as a first battery, a second high voltage battery 12 as a second battery, a first battery voltage detection unit 13, and a second battery. It includes a battery voltage detection unit 14 and a battery ECU (Electronic Control Unit) 15.

The first high-voltage battery 11 is a storage battery mounted on the vehicle 100 and capable of storing electric power. The first high voltage battery 11 has a plurality of battery cells. Each battery cell is composed of a secondary battery that can be charged and discharged, and is composed of, for example, a lithium ion battery. Each battery cell is arranged side by side and is connected in series with a battery cell located next to each other.

The second high-voltage battery 12 is a storage battery mounted on the vehicle 100 and capable of storing electric power. The second high voltage battery 12 has a plurality of battery cells. Each battery cell is composed of a secondary battery that can be charged and discharged, and is composed of, for example, a lithium ion battery. Each battery cell is arranged side by side and is connected in series with a battery cell located next to each other. The second high-voltage battery 12 has a capacity equivalent to that of the first high-voltage battery 11.

The first battery voltage detection unit 13 detects the voltage of the first high voltage battery 11. The first battery voltage detection unit 13 is a voltage detection unit different from the circuit voltage detection unit 33A of the rear power supply box 30A, which will be described later. The first battery voltage detection unit 13 is connected in parallel to the first high voltage battery 11 and detects the voltage between the positive electrode and the negative electrode of the first high voltage battery 11. The first battery voltage detection unit 13 is connected to the battery ECU 15 and outputs the detected voltage V1 which is the detected voltage to the battery ECU 15.

The second battery voltage detection unit 14 detects the voltage of the second high voltage battery 12. The second battery voltage detection unit 14 is a voltage detection unit different from the circuit voltage detection unit 33A of the rear power supply box 30A. The second battery voltage detection unit 14 is connected in parallel to the second high voltage battery 12 and detects the voltage between the positive electrode and the negative electrode of the second high voltage battery 12. The second battery voltage detection unit 14 is connected to the battery ECU 15 and outputs the detected voltage V2, which is the detected voltage, to the battery ECU 15.

The battery ECU 15 monitors the first high voltage battery 11 and the second high voltage battery 12. The battery ECU 15 and the first and second battery voltage detection units 13 and 14 are referred to as a cell voltage sensor (CVS; Cell Voltage Sensor) or a battery management system (BMS; Battery Management System). The battery ECU 15 is connected to the first battery voltage detection unit 13, and the detection voltage V1 is output from the first battery voltage detection unit 13. Further, the battery ECU 15 is connected to the second battery voltage detection unit 14, and the detection voltage V2 is output from the second battery voltage detection unit 14. The battery ECU 15 controls the first high voltage battery 11 and the second high voltage battery 12 based on the detected voltages V1 and V2. The battery ECU 15 controls, for example, to equalize the charge amount of the first high-voltage battery 11 and the charge amount of the second high-voltage battery 12 based on the detected voltages V1 and V2. The battery ECU 15 is connected to the control unit 50 and outputs the detection voltages V1 and V2 to the control unit 50.

The DC charging port 20A is a so-called DC inlet, to which the connector C of the quick charger 2 or the ultra-quick charger 3 is connected. The DC charging port 20A is connected to the rear power supply box 30A, and outputs the power supplied from the quick charger 2 or the ultra-quick charger 3 to the rear power supply box 30A.

The rear power supply box 30A is provided on the rear side of the vehicle 100 in the overall length direction, and turns on and off the electrical connection between the power storage unit 10 and the rear inverter 4A and the rear motor 5A on the rear side of the vehicle 100. Further, the rear power supply box 30A turns on and off the electrical connection between the power storage unit 10 and the DC charging port 20A. The rear power supply box 30A includes a load power switching unit 31A, a main switching unit 32A, and a circuit voltage detecting unit 33A.

The load power switching unit 31A switches the power supplied from the power storage unit 10 to the load unit. The load power switching unit 31A includes a load relay 31a and a load relay 31b. The load relays 31a and 31b energize or cut off the current. The load relay 31a is provided between the positive electrode of the first high-voltage battery 11 or the positive electrode of the second high-voltage battery 12 and the positive electrode of the rear inverter 4A. The load relay 31a energizes or cuts off the current flowing from the positive electrode of the first high voltage battery 11 or the positive electrode of the second high voltage battery 12 to the rear inverter 4A. The load relay 31b is provided between the negative electrode of the first high-voltage battery 11 or the negative electrode of the second high-voltage battery 12 and the negative electrode of the rear inverter 4A. The load relay 31b energizes or cuts off the current flowing from the rear inverter 4A to the negative electrode of the first high voltage battery 11 or the negative electrode of the second high voltage battery 12.

The main switching unit 32A switches the power supplied from the DC charging port 20A to the power storage unit 10. The main switching unit 32A includes an upstream side main relay 32a and a downstream side main relay 32b. The upstream side and downstream side main relays 32a and 32b energize or cut off the current. The upstream main relay 32a is provided between the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11. The upstream main relay 32a energizes or cuts off the current flowing from the DC charging port 20A to the first high voltage battery 11. Further, the upstream main relay 32a is located between the positive electrode of the DC charging port 20A and the positive electrode of the second high voltage battery 12. The upstream main relay 32a energizes or cuts off the current flowing from the DC charging port 20A to the second high voltage battery 12.

The downstream main relay 32b is provided between the negative electrode of the first high voltage battery 11 and the negative electrode of the DC charging port 20A. The downstream main relay 32b energizes or cuts off the current flowing from the negative electrode of the first high voltage battery 11 to the DC charging port 20A. Further, the downstream main relay 32b is located between the negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A. The downstream main relay 32b energizes or cuts off the current flowing from the negative electrode of the second high voltage battery 12 to the DC charging port 20A.

The circuit voltage detection unit 33A detects the voltage of the series circuit P and the parallel circuit Q. The circuit voltage detection unit 33A is connected in parallel to the first high voltage battery 11 and the second high voltage battery 12 constituting the series circuit P, and is connected to the series circuit P by the first high voltage battery 11 and the second high voltage battery 12. Detect the applied voltage. The circuit voltage detection unit 33A is connected to the control unit 50 and outputs the detected detection voltage V3 of the first high voltage battery 11 and the second high voltage battery 12 to the control unit 50.

The circuit voltage detection unit 33A is connected in parallel to the first high voltage battery 11 and detects the voltage applied to the parallel circuit Q by the first high voltage battery 11. The circuit voltage detection unit 33A outputs the detected detection voltage V3 of the first high voltage battery 11 to the control unit 50.

The circuit voltage detection unit 33A is connected in parallel to the second high voltage battery 12, and detects the voltage applied to the parallel circuit Q by the second high voltage battery 12. The circuit voltage detection unit 33A outputs the detected detection voltage V3 of the second high voltage battery 12 to the control unit 50.

The charge switching unit 40 switches the connection circuits of the first and second high-voltage batteries 11 and 12. The charging switching unit 40 is, for example, a series circuit P (see FIG. 3) connecting the first high-voltage battery 11 and the second high-voltage battery 12 in series, or the first high-voltage battery 11 and the second high-voltage battery 12. Is switched to the parallel circuit Q (see FIG. 2) that connects the above in parallel.

The charge switching unit 40 includes a charge relay 41a, a charge relay 41b, a charge relay 41c, and current detection units 42 and 43. The charging relays 41a to 41c energize or cut off the current. The charging relay 41a forms a series circuit P, and is provided between the positive electrode of the second high voltage battery 12 and the negative electrode of the first high voltage battery 11. The charging relay 41a energizes or cuts off the current flowing from the second high voltage battery 12 to the first high voltage battery 11. The charging relay 41a also has a role as a service plug for ensuring electrical safety, and is preferably configured to be physically removable.

As shown in FIG. 3, the series circuit P is a circuit for connecting the first high-voltage battery 11 and the second high-voltage battery 12 in series. In the series circuit P, for example, the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11 are connected, and the negative electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12 are connected via the charging relay 41a. It is connected, and the negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A are connected. In the series circuit P, an upstream main relay 32a is provided between the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11, and the negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A. A downstream main relay 32b is provided between the two.

The charging relay 41b forms a parallel circuit Q, and is provided between the negative electrode of the first high-voltage battery 11 and the negative electrode of the DC charging port 20A. The charging relay 41b energizes or cuts off the current flowing from the negative electrode of the first high voltage battery 11 to the negative electrode of the DC charging port 20A.

The charging relay 41c forms a parallel circuit Q, and is provided between the positive electrode of the DC charging port 20A and the positive electrode of the second high voltage battery 12. The charging relay 41c energizes or cuts off the current flowing from the positive electrode of the DC charging port 20A to the positive electrode of the second high voltage battery 12.

As shown in FIG. 2, the parallel circuit Q is a circuit in which the first high-voltage battery 11 and the second high-voltage battery 12 are connected in parallel. In the parallel circuit Q, for example, the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11 are connected, and the negative electrode of the first high voltage battery 11 and the negative electrode of the DC charging port 20A are connected via the charging relay 41b. The first closed circuit to be connected, the positive electrode of the DC charging port 20A and the positive electrode of the second high voltage battery 12 are connected via the charging relay 41c, and the negative electrode of the second high voltage battery 12 and the DC charging port 20A. It constitutes a second closed circuit to which the negative electrode is connected.

The current detection unit 42 detects the current. The current detection unit 42 is provided between the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11, and detects the current flowing from the DC charging port 20A to the first high voltage battery 11. The current detection unit 42 detects the current flowing from the DC charging port 20A to the first high voltage battery 11 in the series circuit P and the parallel circuit Q, respectively. The current detection unit 42 is connected to the control unit 50 and outputs the detected detection current I1 to the control unit 50.

The current detection unit 43 detects the current. The current detection unit 43 is provided between the negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A, and detects the current flowing from the second high voltage battery 12 to the DC charging port 20A. The current detection unit 43 detects the current flowing from the second high voltage battery 12 to the DC charging port 20A in the series circuit P and the parallel circuit Q, for example. The current detection unit 43 is connected to the control unit 50 and outputs the detected detection current I2 to the control unit 50. Since the current detection units 42 and 43 each detect the detection currents I1 and I2 in the series circuit P, even if one of them fails, the other can detect the current.

The control unit 50 controls the rear power supply box 30A and the charge switching unit 40. For example, when supplying electric power to the rear inverter 4A when discharging, the control unit 50 turns on the charging relays 41b and 41c and turns off the charging relay 41a to form the parallel circuit Q. Then, the control unit 50 turns on the load relays 31a and 31b, electrically connects the power storage unit 10 and the rear inverter 4A via the parallel circuit Q, and supplies power from the power storage unit 10 to the rear inverter 4A. Further, the control unit 50 turns on the charging relay 41a and turns off the charging relays 41b and 41c to form the series circuit P. Then, the control unit 50 turns on the load relays 31a and 31b, electrically connects the power storage unit 10 and the rear inverter 4A via the series circuit P, and supplies electric power from the power storage unit 10 to the rear inverter 4A.

When the connector C of the quick charger 2 is connected to the DC charging port 20A when charging, the control unit 50 controls the charging switching unit 40 to form the parallel circuit Q. For example, as shown in FIG. 2, the control unit 50 turns on the charging relays 41b and 41c and turns off the charging relay 41a to form the parallel circuit Q. Then, the control unit 50 turns on the upstream main relay 32a and the downstream main relay 32b, electrically connects the parallel circuit Q of the charging switching unit 40 and the DC charging port 20A, and is supplied from the quick charger 2. The electric power is charged to the first high voltage battery 11 and the second high voltage battery 12. Note that FIG. 4 illustrates the ON / OFF relationship between the charging relays 41a, 41b, 41c, the upstream main relay 32a, and the downstream main relay 32b during quick charging.

On the other hand, when the connector C of the ultra-rapid charger 3 is connected to the DC charging port 20A when charging, the control unit 50 controls the charging switching unit 40 to form the series circuit P. For example, as shown in FIG. 3, the control unit 50 turns on the charging relay 41a and turns off the charging relays 41b and 41c to form the series circuit P. Then, the control unit 50 turns on the upstream main relay 32a and the downstream main relay 32b to electrically connect the series circuit P of the charging switching unit 40 and the DC charging port 20A, and supplies the power from the ultra-rapid charger 3. The electric power generated is charged to the first high voltage battery 11 and the second high voltage battery 12. Note that FIG. 4 illustrates the ON / OFF relationship of the charging relays 41a, 41b, 41c, the upstream main relay 32a, and the downstream main relay 32b during ultra-rapid charging.

The control unit 50 represents, for example, an input voltage (for example, about 400 V) input from the quick charger 2 via the DC charging port 20A when the connector C of the quick charger 2 is connected to the DC charging port 20A. The charge switching unit 40 is controlled so as to acquire the voltage information and form the parallel circuit Q based on the acquired voltage information. When the connector C of the ultra-rapid charger 3 is connected to the DC charging port 20A, the control unit 50 indicates voltage information representing an input voltage (for example, about 800 V) input from the ultra-rapid charger 3 via the DC charging port 20A. Is acquired, and the charging switching unit 40 is controlled so as to form the series circuit P based on the acquired voltage information.

Further, the control unit 50 is based on the result of detecting the voltage of the power supplied from the quick charger 2 by the circuit voltage detection unit 33A, for example, when the connector C of the quick charger 2 is connected to the DC charging port 20A. The charging switching unit 40 may be controlled. In this case, the control unit 50 detects the voltage of the electric power supplied from the quick charger 2 by turning off all the charging relays 41a to 41c and turning on the upstream side main relay 32a and the downstream side main relay 32b. It is detected by the unit 33A.

Next, an operation example of the power supply system 1 will be described with reference to FIG. FIG. 5 is a flowchart showing an operation example of the power supply system 1 according to the first embodiment. In the power supply system 1, the control unit 50 determines whether or not the input voltage is about 400 V (step S1). When the input voltage is about 400 V (first voltage) (step S1; Yes), the control unit 50 controls the charge switching unit 40 to form the parallel circuit Q (step S2). The control unit 50, for example, turns on the charging relays 41b and 41c and turns off the charging relay 41a to form the parallel circuit Q. Then, the control unit 50 charges the first high-voltage battery 11 and the second high-voltage battery 12 with the electric power supplied from the quick charger 2, and ends the charging process.

On the other hand, when the input voltage is not about 400 V but about 800 V (second voltage) higher than about 400 V, the control unit 50 controls the charge switching unit 40 to form the series circuit P in the case (step S1; No). (Step S3). The control unit 50, for example, turns on the charging relay 41a and turns off the charging relays 41b and 41c to form the series circuit P. Then, the control unit 50 charges the first high-voltage battery 11 and the second high-voltage battery 12 with the electric power supplied from the ultra-rapid charger 3 to end the charging process.

Next, failure detection of the charging relays 41a to 41c will be described. FIG. 6 is a circuit diagram showing an example of detecting an on-stick failure of the charging relays 41a to 41c according to the first embodiment. FIG. 7 is a circuit diagram showing an example of detecting an off-stick failure of the charging relay 41a according to the first embodiment. FIG. 8 is a circuit diagram showing an example of detecting an off-stick failure of the charging relay 41c according to the first embodiment. FIG. 9 is a circuit diagram showing an example of detecting an off-stick failure of the charging relay 41b according to the first embodiment. FIG. 10 is a flowchart showing a failure detection example of the charging relays 41a to 41c according to the first embodiment.

The control unit 50 connects the quick charger 2 or the ultra-rapid charger 3 to the DC charging port 20A, and before supplying power from the quick charger 2 or the ultra-rapid charger 3 to the DC charging port 20A, the control unit 50 is a charging relay. Detect (diagnose) the failure of 41a to 41c. The control unit 50 starts failure detection of the charging relays 41a to 41c immediately after detecting that the connector C of the quick charger 2 or the ultra-rapid charger 3 is connected to the DC charging port 20A, for example.

For example, when the control unit 50 detects a failure of the charging relays 41a to 41c, the control unit 50 turns off the upstream main relay 32a and the downstream main relay 32b, and electrically connects the rear power supply box 30A and the DC charging port 20A. Detects a failure while it is shut off. As shown in FIGS. 6 and 10, the control unit 50 turns off all the charging relays 41a to 41c when detecting an on-stick failure of the charging relays 41a to 41c (step T1). Here, the on-stick failure is a failure in which the charging relays 41a to 41c are stuck on and do not turn off. The control unit 50 acquires the detection voltage V1 of the first high voltage battery 11 from the first battery voltage detection unit 13, and acquires the detection voltage V2 of the second high voltage battery 12 from the second battery voltage detection unit 14 (step). T2). Next, the control unit 50 acquires the detection voltage V3 from the circuit voltage detection unit 33A (step T3).

Next, the control unit 50 determines whether or not the detection voltage V3 is 0V (step T4). When the detection voltage V3 is not 0V (step T4; No), the control unit 50 determines that any of the charging relays 41a to 41c is an on-stick failure (step T5). That is, when the control unit 50 detects the voltage by the circuit voltage detection unit 33A even though all the charging relays 41a to 41c are turned off, at least one of the charging relays 41a to 41c is on-fixed failure. judge.

For example, when the detection voltage V1 of the first high voltage battery 11 and the detection voltage V2 of the second high voltage battery 12 are different from each other, the control unit 50 has the detection voltage V3 equal to the detection voltage V1 of the first high voltage battery 11. In this case, it is determined that the charging relay 41b constituting the parallel circuit Q including the first high-voltage battery 11 has an on-stick failure. On the other hand, when the detection voltage V1 of the first high voltage battery 11 and the detection voltage V2 of the second high voltage battery 12 are different from each other, the control unit 50 has the detection voltage V3 equal to the detection voltage V2 of the second high voltage battery 12. In this case, it is determined that the charging relay 41c constituting the parallel circuit Q including the second high-voltage battery 12 has an on-stick failure. When the detection voltage V3 is equal to the total voltage of the detection voltage V1 of the first high-voltage battery 11 and the detection voltage V2 of the second high-voltage battery 12, the control unit 50 causes the charging relay 41a constituting the series circuit P to turn on and fail. Is determined to be. The control unit 50 stops the power supply system 1 when any one of the charging relays 41a to 41c has an on-stick failure (step T21). The control unit 50 cuts off the circuit of the power supply system 1 by turning off all the relays of the load power switching unit 31A, the main switching unit 32A, and the charging switching unit 40, for example, and sets the failure location and the failure state to the outside. Transmit to the ECU.

When the detection voltage V3 is 0V (step T4; Yes), the control unit 50 determines that the charging relays 41a to 41c are not on-stick failures, and detects the first high-voltage battery 11 and the second high-voltage battery 12. A failure of the charging relay 41a is detected based on the voltage V3. For example, as shown in FIG. 7, the control unit 50 turns on the charging relay 41a to form a series circuit P (step T6), and acquires the detection voltage V3 from the circuit voltage detection unit 33A (step T7). Note that FIG. 4 shows an ON / OFF relationship of each relay when detecting a failure of the charging relay 41a. The control unit 50 determines whether or not the detection voltage V3 is equal to the total voltage of the detection voltage V1 and the detection voltage V2 (step T8). When the detection voltage V3 is not equal to the total voltage of the detection voltage V1 and the detection voltage V2 (step T8; No), the control unit 50 determines that the charging relay 41a constituting the series circuit P has an off-fixed failure (step). T9). Here, the off-sticking failure is, for example, a failure in which the charging relays 41a to 41c are stuck to OFF and do not turn ON. The control unit 50 stops the power supply system 1 when the charging relay 41a is off and stuck (step T21).

When the detection voltage V3 is equal to the total voltage of the detection voltage V1 and the detection voltage V2 (step T8; Yes), the control unit 50 determines that the charging relay 41a is not an off-stick failure. Then, the control unit 50 has a detection voltage V2 of the second high voltage battery 12 detected by the second battery voltage detection unit 14 and a detection voltage V3 of the second high voltage battery 12 detected by the circuit voltage detection unit 33A. The failure of the charging relay 41c is detected based on the above. The control unit 50 turns off the charging relay 41a (step T10) and turns on the charging relay 41c (step T11), for example. Note that FIG. 4 shows the ON / OFF relationship of each relay when detecting the failure of the charging relay 41c. The control unit 50 acquires the detection voltage V3 from the circuit voltage detection unit 33A (step T12), and determines whether or not the acquired detection voltage V3 is equal to the detection voltage V2 of the second high voltage battery 12 (step T13). .. When the detection voltage V3 is not equal to the detection voltage V2 of the second high voltage battery 12 (step T13; No), the control unit 50 turns off the charging relay 41c constituting the parallel circuit Q including the second high voltage battery 12. It is determined that the failure is a sticking failure (step T14). The control unit 50 stops the power supply system 1 when the charging relay 41c is off and stuck (step T21).

When the detection voltage V3 is equal to the detection voltage V2 of the second high-voltage battery 12 (step T13; Yes), the control unit 50 determines that the charging relay 41c is not an off-stick failure. Then, the control unit 50 has a detection voltage V1 of the first high voltage battery 11 detected by the first battery voltage detection unit 13 and a detection voltage V3 of the first high voltage battery 11 detected by the circuit voltage detection unit 33A. The failure of the charging relay 41b is detected based on the above. For example, the control unit 50 turns off the charging relay 41c (step T15) and turns on the charging relay 41b (step T16). Note that FIG. 4 shows an ON / OFF relationship of each relay when detecting a failure of the charging relay 41b. The control unit 50 acquires the detection voltage V3 from the circuit voltage detection unit 33A (step T17), and determines whether or not the acquired detection voltage V3 is equal to the detection voltage V1 of the first high voltage battery 11 (step T18). .. When the detection voltage V3 is not equal to the detection voltage V1 of the first high-voltage battery 11 (step T18; No), the control unit 50 turns off the charging relay 41b constituting the parallel circuit Q including the first high-voltage battery 11. It is determined that the failure is a sticking failure (step T19). The control unit 50 stops the power supply system 1 when the charging relay 41b is off and stuck (step T21). When the detection voltage V3 is equal to the detection voltage V1 of the first high-voltage battery 11 (step T18; Yes), the control unit 50 determines that the charging relay 41b is not an off-stick failure. Then, the control unit 50 turns off the charging relay 41b (step T20), and ends the failure detection.

As described above, the power supply system 1 according to the first embodiment includes the first high-voltage battery 11, the second high-voltage battery 12, the charging switching unit 40, the DC charging port 20A, and the control unit 50. Be prepared. The first high-voltage battery 11 is a battery mounted on the vehicle 100 and capable of storing electric power. The second high-voltage battery 12 is a battery mounted on the vehicle 100 and capable of storing electric power. The charge switching unit 40 is a series circuit P that connects the first high voltage battery 11 and the second high voltage battery 12 in series, or a parallel circuit that connects the first high voltage battery 11 and the second high voltage battery 12 in parallel. It is a relay that can be switched to Q. The DC charging port 20A is connected to the quick charger 2 or the ultra-rapid charger 3 and inputs the electric power supplied from the quick charger 2 or the ultra-rapid charger 3. The control unit 50 controls the charge switching unit 40 based on the input voltage of the electric power input from the DC charging port 20A. When the input voltage is the first voltage (for example, about 400 V), the control unit 50 controls the charge switching unit 40 to form the parallel circuit Q, and supplies the power supplied from the quick charger 2 to the first high voltage battery 11. And the second high voltage battery 12 is charged. When the input voltage is a second voltage (for example, about 800 V) higher than the first voltage (for example, about 400 V), the control unit 50 controls the charge switching unit 40 to form a series circuit P, and the ultra-rapid charger 3 The first high-voltage battery 11 and the second high-voltage battery 12 are charged with the power supplied from.

With this configuration, the power supply system 1 forms the parallel circuit Q or the series circuit P according to the input voltage input by the DC charging port 20A. Therefore, even if the input voltage is different, the first high voltage battery 11 and the second high voltage The voltage battery 12 can be charged properly. As a result, the power supply system 1 can support a plurality of external chargers having different voltages, such as the quick charger 2 and the ultra-quick charger 3, so that the versatility can be improved.

In the power supply system 1, the charging switching unit 40 includes a charging relay 41a forming the series circuit P, a charging relay 41b forming the parallel circuit Q, and a charging relay 41c forming the parallel circuit Q. In the series circuit P, the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11 are connected, and the negative electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12 are connected via the charging relay 41a. , The negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A are connected. In the parallel circuit Q, the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11 are connected, the negative electrode of the first high voltage battery 11 and the negative electrode of the DC charging port 20A are connected via the charging relay 41b, and further. , The positive electrode of the DC charging port 20A and the positive electrode of the second high voltage battery 12 are connected via the charging relay 41c, and the negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A are connected. When the input voltage is the first voltage (for example, about 400V), the control unit 50 turns on the charging relay 41b and the charging relay 41c and turns off the charging relay 41a to form the parallel circuit Q. When the input voltage is the second voltage (for example, about 800V), the control unit 50 turns on the charging relay 41a and turns off the charging relay 41b and the charging relay 41c to form the series circuit P. With this configuration, the power supply system 1 can form the series circuit P and the parallel circuit Q while suppressing an increase in the number of charging relays 41a to 41c.

The power supply system 1 further includes a circuit voltage detection unit 33A, a first battery voltage detection unit 13, and a second battery voltage detection unit 14. The circuit voltage detection unit 33A has a voltage applied to the series circuit P by the first high voltage battery 11 and the second high voltage battery 12, a voltage applied to the parallel circuit Q by the first high voltage battery 11, and a second high voltage. The voltage applied to the parallel circuit Q can be detected by the battery 12. The first battery voltage detection unit 13 can detect the voltage between the positive electrode and the negative electrode of the first high voltage battery 11. The second battery voltage detection unit 14 can detect the voltage between the positive electrode and the negative electrode of the second high voltage battery 12. The control unit 50 connects the quick charger 2 or the ultra-rapid charger 3 to the DC charging port 20A, and before supplying power from the quick charger 2 or the ultra-rapid charger 3 to the DC charging port 20A, the circuit voltage. Based on the detection results of the detection unit 33A, the first battery voltage detection unit 13, and the second battery voltage detection unit 14, the failure of the charging relay 41a, the charging relay 41b, and the charging relay 41c is detected. As a result, the power supply system 1 can detect a failure of the charging relays 41a to 41c before the start of charging, and can prevent a charging error that occurs during charging. Thereby, the power supply system 1 can improve the reliability.

In the power supply system 1, the control unit 50 has a detection voltage V3 of the first high voltage battery 11 and the second high voltage battery 12 detected by the circuit voltage detection unit 33A, and a first battery voltage detection unit 13 detected by the first battery voltage detection unit 13. 1 Failure of the charging relay 41a is detected based on the detection voltage V1 of the high voltage battery 11 and the detection voltage V2 of the second high voltage battery 12 detected by the second battery voltage detection unit 14. The control unit 50 is based on the detection voltage V3 of the first high voltage battery 11 detected by the circuit voltage detection unit 33A and the detection voltage V1 of the first high voltage battery 11 detected by the first battery voltage detection unit 13. Detects a failure of the charging relay 41b. The control unit 50 is based on the detection voltage V3 of the second high voltage battery 12 detected by the circuit voltage detection unit 33A and the detection voltage V2 of the second high voltage battery 12 detected by the second battery voltage detection unit 14. Detects a failure of the charging relay 41c. As a result, the power supply system 1 determines the failure of the charging relays 41a to 41c with reference to the detected voltages V1 and V2, so that the failure can be accurately determined. The power supply system 1 accurately determines the failure of the charging relays 41a to 41c even when the voltages of the first high-voltage battery 11 and the second high-voltage battery 12 differ depending on the situation due to, for example, a difference in the amount of charge or deterioration. be able to.

[Second Embodiment]
Next, the power supply system 1A according to the second embodiment will be described. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the second embodiment, the power supply system 1A charges the high-voltage power supplied by the quick charger 2 or the ultra-fast charger 3 described above, or the low voltage supplied from the AC power supply 6 for home use or the like. It boosts the power of the battery and charges it. Then, the power supply system 1A supplies electric power to the rear inverter 4A and the rear motor 5A on the rear side of the vehicle 100, and supplies electric power to the front inverter 4B and the front motor 5B on the front side of the vehicle 100.

The power supply system 1A according to the second embodiment is different from the power supply system 1 according to the first embodiment in that it includes a front power supply box 30B that distributes electric power to the front inverter 4B and the front motor 5B on the front side of the vehicle 100. different. As shown in FIG. 11, the power supply system 1A includes a power storage unit 10, a DC charging port 20A, an AC charging port 20B as a second input unit, a rear power supply box 30A, a front power supply box 30B, and a charging switching unit. It includes 40A, a control unit 50, and an OBC (On Board Charger) 60. FIG. 11 is a circuit diagram showing a configuration example of the power supply system 1A according to the second embodiment. The power storage unit 10 is configured by connecting the first high-voltage battery 11 and the second high-voltage battery 12 by a series circuit P or a parallel circuit Q.

The DC charging port 20A is a so-called DC inlet, and is connected to the connector C of the quick charger 2 or the ultra-quick charger 3 as described above. The DC charging port 20A is connected to the front power supply box 30B, and outputs the power supplied from the quick charger 2 or the ultra-quick charger 3 to the front power supply box 30B.

The AC charging port 20B is a so-called AC inlet, which is connected to an AC power source 6 having a lower charging voltage than the quick charger 2 and inputs power supplied from the AC power source 6. The AC charging port 20B is connected to the OBC 60, and outputs the power supplied from the AC power supply 6 to the rear power supply box 30A via the OBC 60.

The rear power supply box 30A turns on / off (ON / OFF) the electrical connection between the power storage unit 10 and the rear inverter 4A on the rear side of the vehicle 100. Further, the rear power supply box 30A turns on and off the electrical connection between the power storage unit 10 and the AC charging port 20B.

The front power supply box 30B is provided on the front side of the vehicle 100 in the overall length direction, and turns on and off the electrical connection between the power storage unit 10 and the front inverter 4B on the front side of the vehicle 100. Further, the front power supply box 30B turns on and off the electrical connection between the power storage unit 10 and the DC charging port 20A. The front power supply box 30B includes a load power switching unit 31B, a main switching unit 32B, and a circuit voltage detecting unit 33B.

The load power switching unit 31B switches the power supplied from the power storage unit 10 to the load unit. The load power switching unit 31B includes a load relay 31c and a load relay 31d. The load relays 31c and 31b energize or cut off the current. The load relay 31c is provided between the positive electrode of the first high voltage battery 11 or the positive electrode of the second high voltage battery 12 and the positive electrode of the front inverter 4B. The load relay 31c energizes or cuts off the current flowing from the positive electrode of the first high voltage battery 11 or the positive electrode of the second high voltage battery 12 to the front inverter 4B. The load relay 31d is provided between the negative electrode of the first high voltage battery 11 or the negative electrode of the second high voltage battery 12 and the negative electrode of the front inverter 4B. The load relay 31d energizes or cuts off the current flowing from the front inverter 4B to the negative electrode of the first high voltage battery 11 or the negative electrode of the second high voltage battery 12.

The main switching unit 32B switches the power supplied from the DC charging port 20A to the power storage unit 10. The main switching unit 32B includes an upstream side main relay 32c and a downstream side main relay 32d. The upstream side and downstream side main relays 32c and 32d energize or cut off the current. The upstream main relay 32c is provided between the positive electrode of the DC charging port 20A and the positive electrode of the first high voltage battery 11. The upstream main relay 32c energizes or cuts off the current flowing from the DC charging port 20A to the first high voltage battery 11. Further, the upstream main relay 32c is located between the positive electrode of the DC charging port 20A and the positive electrode of the second high voltage battery 12. The upstream main relay 32c energizes or cuts off the current flowing from the DC charging port 20A to the second high voltage battery 12.

The downstream main relay 32d is provided between the negative electrode of the first high voltage battery 11 and the negative electrode of the DC charging port 20A. The downstream main relay 32d energizes or cuts off the current flowing from the negative electrode of the first high voltage battery 11 to the DC charging port 20A. Further, the downstream main relay 32d is located between the negative electrode of the second high voltage battery 12 and the negative electrode of the DC charging port 20A. The downstream main relay 32d energizes or cuts off the current flowing from the negative electrode of the second high voltage battery 12 to the DC charging port 20A.

The circuit voltage detection unit 33B detects the voltage of the series circuit P and the parallel circuit Q. The circuit voltage detection unit 33B is connected in parallel to the first high voltage battery 11 and the second high voltage battery 12 constituting the series circuit P, and is connected to the series circuit P by the first high voltage battery 11 and the second high voltage battery 12. Detect the applied voltage. The circuit voltage detection unit 33B is connected to the control unit 50 and outputs the detected detection voltage V4 of the first high voltage battery 11 and the second high voltage battery 12 to the control unit 50.

The circuit voltage detection unit 33B is connected in parallel to the first high voltage battery 11 and detects the voltage applied to the parallel circuit Q by the first high voltage battery 11. The circuit voltage detection unit 33B outputs the detected detection voltage V4 of the first high voltage battery 11 to the control unit 50.

The circuit voltage detection unit 33B is connected in parallel to the second high voltage battery 12, and detects the voltage applied to the parallel circuit Q by the second high voltage battery 12. The circuit voltage detection unit 33B outputs the detected detection voltage V4 of the second high voltage battery 12 to the control unit 50.

The charging switching unit 40A includes a charging relay 41a, a charging relay 41b, a charging relay 41c, a charging relay 41d, and a resistor R. The charging relays 41a to 41c have the same configuration as the charging relay described in the first embodiment. The charging relay 41d is provided between the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12. In this example, the charging relay 41d is provided between the positive electrode of the first high voltage battery 11 and the charging relay 41c. The charging relay 41d turns on and off the electrical connection between the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12. The resistor R is connected in parallel to the charging relay 41d.

The OBC 60 converts electric power. The OBC 60 is connected to the AC charging port 20B, converts the AC power output from the AC charging port 20B into DC power, and boosts the DC power. The OBC 60 is connected to the rear power supply box 30A and outputs the boosted DC power to the power storage unit 10 via the rear power supply box 30A. In this case, it is preferable that the power storage unit 10 forms the parallel circuit Q in order to suppress the loss at the time of boosting by the onboard charger.

Next, an operation example of the power supply system 1A when the vehicle is running will be described. FIG. 12 is a circuit diagram showing an operation example of the power supply system 1A according to the second embodiment when the vehicle is running. As shown in FIG. 12, the control unit 50 turns on the charging relays 41b, 41c, 41d, the load relays 31a, 31b, 31c, 31d, and the charging relay 41a, the upstream main relays 32a, 32c, as shown in FIG. , The downstream side main relays 32b and 32d are turned off. As a result, the control unit 50 forms a parallel circuit Q in which the first high-voltage battery 11 and the second high-voltage battery 12 are connected in parallel to each other, and the first high-voltage battery 11 and the second high-voltage battery 11 and the second formed in the parallel circuit Q. Power can be supplied from the high voltage battery 12 to the rear inverter 4A and the front inverter 4B. At this time, the rear inverter 4A and the front inverter 4B operate at the output voltage of the rear inverter 4A or the front inverter 4B (for example, about 400V). Note that FIG. 20 illustrates the ON / OFF relationship of each relay when the vehicle is running.

Next, an operation example at the time of quick charging of the power supply system 1A will be described. FIG. 13 is a circuit diagram showing an operation example of the power supply system 1A according to the second embodiment during rapid charging. In the case of quick charging, the control unit 50 controls the charge switching unit 40A to form a parallel circuit Q in which the first high voltage battery 11 and the second high voltage battery 12 are connected in parallel. For example, as shown in FIG. 13, the control unit 50 turns on the charging relays 41b, 41c, 41d and turns off the charging relay 41a to form the parallel circuit Q. Then, the control unit 50 turns on the upstream main relay 32c and the downstream main relay 32d to electrically connect the parallel circuit Q of the charging switching unit 40A and the DC charging port 20A, and DC charges from the quick charger 2. The electric power supplied through the port 20A is charged into the first high voltage battery 11 and the second high voltage battery 12. At this time, the supply voltage supplied from the quick charger 2 is a voltage equivalent to the output voltage (for example, about 400 V) of the first high voltage battery 11 or the second high voltage battery 12. Note that FIG. 20 illustrates the ON / OFF relationship of each relay in quick charging.

Next, an operation example of the power supply system 1A at the time of ultra-rapid charging will be described. FIG. 14 is a circuit diagram showing an operation example of the power supply system 1A according to the second embodiment at the time of ultra-rapid charging. In the case of ultra-rapid charging, the control unit 50 controls the charge switching unit 40A to form the series circuit P. For example, as shown in FIG. 14, the control unit 50 turns on the charging relay 41a and turns off the charging relays 41b, 41c, 41d to form the series circuit P. Then, the control unit 50 turns on the upstream side main relay 32c and the downstream side main relay 32d to electrically connect the series circuit P of the charging switching unit 40A and the DC charging port 20A, and the ultra-rapid charger 3 to DC. The power supplied through the charging port 20A is charged to the first high voltage battery 11 and the second high voltage battery 12. At this time, the supply voltage supplied from the ultra-rapid charger 3 is a voltage equivalent to the total output voltage (for example, about 800 V) of the first high-voltage battery 11 and the second high-voltage battery 12. Note that FIG. 20 illustrates the ON / OFF relationship of each relay in ultra-rapid charging.

Next, an operation example at the time of front precharging of the power supply system 1A will be described. FIG. 15 is a circuit diagram showing an operation example at the time of front precharging of the power supply system 1A according to the second embodiment. A capacitor for smoothing the power supply voltage is generally provided on the input side of the front inverter 4B or the like, which is a high voltage load unit. It is preferable that the power supply system 1A performs front precharging in which the capacitor is precharged (precharged) when the power supply system 1A is started.

When performing front precharging, the control unit 50 turns on the charging relay 41c, the load relay 31c, the load relay 31d, and turns off the charging relay 41d and the like, for example, as shown in FIG. As a result, the control unit 50 can connect the second high voltage battery 12 and the front inverter 4B via the resistor R. As a result, the control unit 50 can supply the electric power supplied from the second high voltage battery 12 to the front inverter 4B via the resistor R, and can charge the input side capacitor of the front inverter 4B or the like. .. Note that FIG. 20 illustrates the ON / OFF relationship of each relay at the time of front precharging.

Next, an operation example at the time of reapply charging of the power supply system 1A will be described. FIG. 16 is a circuit diagram showing an operation example at the time of reapply charging of the power supply system 1A according to the second embodiment. A capacitor for smoothing the power supply voltage is generally provided on the input side of the rear inverter 4A or the like, which is a high voltage load unit. When the power supply system 1A is started, the power supply system 1A preferably performs reappli charge to precharge (precharge) this capacitor.

When performing reappli charging, the control unit 50 turns on the charging relay 41b, the load relay 31a, the load relay 31b, and turns off the charging relay 41d and the like, for example, as shown in FIG. As a result, the control unit 50 can connect the first high voltage battery 11 and the rear inverter 4A via the resistor R. As a result, the control unit 50 can supply the power supplied from the first high-voltage battery 11 to the rear inverter 4A via the resistor R, and can charge the input-side capacitor of the rear inverter 4A or the like. .. Since the control unit 50 performs reappli charge and front precharge via the same resistor R, the circuit configuration can be simplified. Note that FIG. 20 illustrates the ON / OFF relationship of each relay at the time of reappli charging.

Next, an operation example during the battery equalization process of the power supply system 1A will be described. FIG. 17 is a circuit diagram showing an operation example of the power supply system 1A according to the second embodiment during the battery equalization process. When the control unit 50 performs the battery equalization process for equalizing the voltages of the first high voltage battery 11 and the second high voltage battery 12, for example, as shown in FIG. 17, the charging relays 41b and 41c are turned on and Turn off the charging relay 41d and the like. As a result, the control unit 50 forms a closed circuit that connects the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12 via the resistor R. Then, the control unit 50 applies a current through the resistor R from the high potential side to the low potential side in the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12, and equalizes the voltage of each battery. To become. Note that FIG. 20 illustrates the ON / OFF relationship of each relay during the battery equalization process.

Next, an operation example in the battery equalization process of the power supply system 1A will be described with reference to the flowchart. FIG. 18 is a flowchart showing an operation example of the power supply system 1A according to the second embodiment during the battery equalization process. This battery equalization process is performed, for example, when the vehicle 100 is stopped. As shown in FIG. 18, the control unit 50 acquires the battery state when the vehicle 100 is stopped (step U1). For example, the control unit 50 acquires the detection voltage V1 of the first high voltage battery 11 from the first battery voltage detection unit 13 described above, and obtains the detection voltage V2 of the second high voltage battery 12 from the second battery voltage detection unit 14. get. Next, the control unit 50 determines whether or not the potential difference between the first high-voltage battery 11 and the second high-voltage battery 12 is within the permissible range (step U2). The control unit 50 compares, for example, the detection voltage V1 of the first high-voltage battery 11 and the detection voltage V2 of the second high-voltage battery 12, and whether or not the potential difference between these detection voltages V1 and V2 is within the permissible range. Is determined. When the potential difference between the first high-voltage battery 11 and the second high-voltage battery 12 is within the permissible range (step U2; Yes), the control unit 50 arranges the first high-voltage battery 11 and the second high-voltage battery 12 in parallel. Perform the parallel connection process to connect (step U3). On the other hand, when the potential difference between the first high-voltage battery 11 and the second high-voltage battery 12 is not within the permissible range (step U2; No), the control unit 50 performs the battery equalization process (step U4). The control unit 50 is closed, for example, by turning on the charging relays 41b and 41c and turning off the charging relays 41d and the like, and connecting the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12 via the resistor R. A circuit is formed, and a current is passed through the resistor R from the high potential side to the low potential side. Then, the control unit 50 returns to step U1, acquires the battery state again, and repeats the above-mentioned process. As a result, when the first high voltage battery 11 and the second high voltage battery 12 are connected in parallel, the control unit 50 can keep the potential difference of each battery within an allowable range and prevent an excessive current from flowing. it can.

Next, an operation example when the battery of the power supply system 1A is abnormal will be described. FIG. 19 is a circuit diagram showing an operation example of the power supply system 1A according to the second embodiment when the battery is abnormal. When one of the first high-voltage battery 11 and the second high-voltage battery 12 is abnormal, the control unit 50 uses the other of the first high-voltage battery 11 and the second high-voltage battery 12 to connect the rear inverter 4A and the front inverter 4B. Control to supply power. In this example, the case where the second high voltage battery 12 is abnormal will be described. For example, as shown in FIG. 19, the control unit 50 turns on the charging relays 41b and 41d and the load relays 31a to 31d and the charging relay (switch for shutting off) 41c when the second high voltage battery 12 is abnormal. Etc. are turned off. As a result, the control unit 50 connects the first high-voltage battery 11, the rear inverter 4A, and the front inverter 4B, and disconnects the second high-voltage battery 12 from the rear inverter 4A and the front inverter 4B, and the second high-voltage battery. 12 can be blocked. As a result, when the second high-voltage battery 12 is abnormal, the control unit 50 can supply electric power from the first high-voltage battery 11 to the rear inverter 4A and the front inverter 4B, and the vehicle 100 continues to run. can do.

Next, an operation example when the battery of the power supply system 1A is abnormal will be described with reference to the flowchart. FIG. 21 is a flowchart showing an operation example when the battery of the power supply system 1A according to the second embodiment is abnormal. The control unit 50 acquires the battery state as shown in FIG. 21 (step W1). For example, the control unit 50 acquires the detection voltage V1 of the first high voltage battery 11 from the first battery voltage detection unit 13 described above, and obtains the detection voltage V2 of the second high voltage battery 12 from the second battery voltage detection unit 14. get. In addition to the detected voltages V1 and V2, the battery state may include the current, temperature, charge rate, degree of deterioration, and the like of each battery. Next, the control unit 50 compares the battery state of the first high-voltage battery 11 with the battery state of the second high-voltage battery 12 (step W2).

When the first high-voltage battery 11 does not output a predetermined voltage or the like (step W3; Yes), the control unit 50 shuts off the first high-voltage battery 11 (step W4), and the second high-voltage battery The process is terminated by switching from 12 to supply power to the rear inverter 4A and the front inverter 4B. On the other hand, when the first high voltage battery 11 is not abnormal (step W3; No) and the second high voltage battery 12 is abnormal (step W5; Yes), the control unit 50 shuts off the second high voltage battery 12. (Step W6), the first high-voltage battery 11 switches to supply power to the rear inverter 4A and the front inverter 4B, and the process ends. In step W5 described above, when the second high-voltage battery 12 is not abnormal (step W5; No), both batteries are normal, so the control unit 50 ends the process as it is. In addition, when both the first high voltage battery 11 and the second high voltage battery 12 do not output a predetermined voltage or other abnormalities, the control unit 50 shuts off the battery in a worse condition and powers the remaining battery. May be supplied.

As described above, the power supply system 1A according to the second embodiment includes a rear power supply box 30A and a front power supply box 30B. The first high-voltage battery 11 and the second high-voltage battery 12 are connected by a series circuit P or a parallel circuit Q to form a power storage unit 10. The rear power supply box 30A is provided on the rear side of the vehicle 100 in the overall length direction, and turns on and off the electrical connection between the power storage unit 10 and the rear inverter 4A of the vehicle 100. The front power supply box 30B is provided on the front side in the total length direction of the vehicle 100, and turns on and off the electrical connection between the power storage unit 10 and the front inverter 4B of the vehicle 100. The front power supply box 30B turns on and off the electrical connection between the power storage unit 10 and the DC charging port 20A. With this configuration, the power supply system 1A can appropriately distribute electric power to the rear inverter 4A provided on the rear side of the vehicle 100 and the front inverter 4B provided on the front side of the vehicle 100. Further, the power supply system 1A can appropriately charge the power storage unit 10 with the electric power supplied through the DC charging port 20A.

The power supply system 1A is connected to an AC power source 6 having a charging voltage lower than that of the quick charger 2, and includes an AC charging port 20B for inputting power supplied from the AC power source 6. The rear power supply box 30A turns on and off the electrical connection between the power storage unit 10 and the AC charging port 20B. With this configuration, the power supply system 1A can properly charge the power storage unit 10 with the electric power supplied through the AC charging port 20B.

In the power supply system 1A, the charging switching unit 40A includes a charging relay 41d and a resistor R. The charging relay 41d is provided between the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12, and is located between the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12. Turn electrical connections on and off. The resistor R is connected in parallel to the charging relay 41d. When the control unit 50 equalizes the voltages of the first high voltage battery 11 and the second high voltage battery 12, the control unit 50 turns off the charging relay 41d and uses the resistor R to turn off the positive voltage and the second high voltage of the first high voltage battery 11. A closed circuit is formed to connect the positive voltage of the battery 12. Then, the control unit 50 passes a current through the resistor R from the high potential side to the low potential side in the positive electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12.

With this configuration, the power supply system 1A can eliminate the potential difference when the first high voltage battery 11 and the second high voltage battery 12 have a potential difference. As a result, the power supply system 1A can suppress the flow of an excessive current due to the potential difference when the parallel circuit Q is formed. Further, since the power supply system 1A also uses the resistor R used at the time of precharging to eliminate the potential difference, the number of parts can be reduced. As a result, the power supply system 1A can suppress the increase in size of the circuit, and can realize space saving and cost reduction.

The power supply system 1A includes a charging relay 41b capable of shutting off the first high-voltage battery 11 and a charging relay 41c capable of shutting off the second high-voltage battery 12. When the second high-voltage battery 12 is abnormal, the control unit 50 turns off the charging relay 41c to shut off the second high-voltage battery 12, and from the first high-voltage battery 11 to the rear inverter 4A of the vehicle 100 and the vehicle 100. Power is supplied to the front inverter 4B of. On the other hand, when the first high-voltage battery 11 is abnormal, the control unit 50 turns off the charging relay 41b to shut off the first high-voltage battery 11, and the second high-voltage battery 12 to the rear inverter 4A of the vehicle 100 and the vehicle 100. Power is supplied to the front inverter 4B of the vehicle 100. With this configuration, the power supply system 1A supplies power to the other of the first high-voltage battery 11 and the second high-voltage battery 12 even when one of the first high-voltage battery 11 and the second high-voltage battery 12 is abnormal. This can minimize the impact of battery malfunction on the system. As a result, the power supply system 1A can secure the power supply necessary for traveling the vehicle, and can suppress the deterioration of the reliability of the system.

[Third Embodiment]
Next, the power supply system 1B according to the third embodiment will be described. FIG. 22 is a circuit diagram showing a configuration example of the power supply system 1B according to the third embodiment. In the third embodiment, the same components as those in the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. In the third embodiment, the power supply system 1B supplies power to the motor inverter 7 (second load unit) from the first and second high-voltage batteries 11 and 12 formed in the series circuit P. 2 Different from the embodiment. Further, the power supply system 1B is different from the first and second embodiments in that constant current control is performed when the charging rates are equalized by the FETs 41e and 41f.

As shown in FIG. 22, the power supply system 1B includes a first high-voltage battery 11, a second high-voltage battery 12, a BMS (Battery Management System) 13A, a BMS 14A, load power switching units 31C and 31D, and main parts. It includes a switching unit 32C, a quick charging port 20C, and a charging switching unit 40B.

The BMS 13A monitors the state of the first high voltage battery 11. The BMS 13A monitors, for example, the total voltage and remaining capacity of the first high-voltage battery 11, the input / output current, the voltage of each battery cell of the first high-voltage battery 11, and the like. The BMS 13A is connected to the control unit 50 and outputs the monitoring result of the first high voltage battery 11 to the control unit 50.

The BMS 14A monitors the state of the second high voltage battery 12. The BMS 14A monitors, for example, the total voltage and remaining capacity of the second high-voltage battery 12, the input / output current, the voltage of each battery cell of the second high-voltage battery 12, and the like. The BMS 14A is connected to the control unit 50 and outputs the monitoring result of the second high voltage battery 12 to the control unit 50.

The quick charging port 20C is a so-called inlet, and the connector C of the quick charger 2 or the ultra-quick charger 3 described above is connected to the quick charging port 20C. The quick charging port 20C is connected to the charging switching unit 40B via the main switching unit 32C, and outputs the power supplied from the quick charger 2 or the ultra-quick charger 3 to the charging switching unit 40B.

The main switching unit 32C switches the power supplied from the quick charging port 20C to the power storage unit 10. The main switching unit 32C is provided between the quick charging port 20C and the power storage unit 10 (first and second high-voltage batteries 11, 12). The main switching unit 32C energizes or cuts off the current flowing from the quick charging port 20C to the power storage unit 10.

The load power switching unit 31C switches the power supplied from the power storage unit 10 to the motor inverter 7. The load power switching unit 31C is provided between the power storage unit 10 and the motor inverter 7. The load power switching unit 31C energizes or cuts off the current flowing from the power storage unit 10 to the motor inverter 7.

The load power switching unit 31D switches the power supplied from the power storage unit 10 to the high voltage load unit 8. Here, the high voltage load unit 8 is, for example, an electric A / C compressor, a PTC (Positive Temperature Coefficient) heater, or the like. The load power switching unit 31D is provided between the power storage unit 10 and the high voltage load unit 8. The load power switching unit 31D energizes or cuts off the current flowing from the power storage unit 10 to the high voltage load unit 8.

The charge switching unit 40B switches the connection circuits of the first and second high-voltage batteries 11 and 12. The charging switching unit 40B is, for example, a series circuit P (see FIG. 26) connecting the first high voltage battery 11 and the second high voltage battery 12 in series, or the first high voltage battery 11 and the second high voltage battery 12 Is switched to the parallel circuit Q (see FIG. 27) which connects the above in parallel.

The charging switching unit 40B includes a charging relay 41a, a charging relay 41b, a charging relay 41c, a voltage monitoring unit 33, an FET 41e as a first switch for constant current, and a FET 41f as a second switch for constant current. , 41g, 41h of the drive circuit, and the control unit 50 are included. The charging relays 41a to 41c energize or cut off the current. The charging relay 41a forms a series circuit P, and is provided between the positive electrode of the second high voltage battery 12 and the negative electrode of the first high voltage battery 11. The charging relay 41a energizes or cuts off the current flowing from the second high voltage battery 12 to the first high voltage battery 11.

The series circuit P is a circuit for connecting the first high voltage battery 11 and the second high voltage battery 12 in series. In the series circuit P, for example, as shown in FIG. 26, the positive electrode of the quick charging port 20C and the positive electrode of the first high voltage battery 11 are connected, and the negative electrode of the first high voltage battery 11 and the positive electrode of the second high voltage battery 12 are connected. Is connected via the charging relay 41a, and the negative electrode of the second high voltage battery 12 and the negative electrode of the quick charging port 20C are connected.

The charging relay 41b forms a parallel circuit Q, and is provided between the negative electrode of the first high-voltage battery 11 and the negative electrode of the quick charging port 20C. The charging relay 41b energizes or cuts off the current flowing from the negative electrode of the first high voltage battery 11 to the negative electrode of the quick charging port 20C.

The charging relay 41c forms a parallel circuit Q, and is provided between the positive electrode of the quick charging port 20C and the positive electrode of the second high voltage battery 12. The charging relay 41c energizes or cuts off the current flowing from the positive electrode of the quick charging port 20C to the positive electrode of the second high voltage battery 12.

The voltage monitoring unit 33 monitors the voltage of the series circuit P and the parallel circuit Q. The voltage monitoring unit 33 is connected in parallel to the first high-voltage battery 11 and the second high-voltage battery 12 constituting the series circuit P. The voltage monitoring unit 33 detects the voltage input to the series circuit P from the quick charging port 20C. Further, the voltage monitoring unit 33 is connected in parallel to the first high voltage battery 11 and the second high voltage battery 12 constituting the parallel circuit Q. The voltage monitoring unit 33 detects the voltage input to the parallel circuit Q from the quick charging port 20C. The voltage monitoring unit 33 is connected to the control unit 50 and outputs the detected voltage to the control unit 50.

The FETs 41e and 41f energize or cut off the current. The FETs 41e and 41f are, for example, N-channel type MOS (Metal-Oxide-Semiconductor) FETs, but are not limited thereto. The FET 41e is provided between the positive electrode of the first high voltage battery 11 and the quick charging port 20C. The FET 41e is turned on by the drive circuit 41g at the time of charging, and energizes the current flowing from the quick charging port 20C to the positive electrode of the first high voltage battery 11. Further, the FET 41e is turned off by the drive circuit 41g at the time of charging, and cuts off the current flowing back from the positive electrode of the first high voltage battery 11 to the quick charging port 20C.

The FET 41e is also arranged between the positive electrode of the first high voltage battery 11 and the high voltage load unit 8. The FET 41e is turned on by the drive circuit 41g at the time of discharging, and energizes the current flowing from the first high voltage battery 11 to the high voltage load unit 8. Further, the FET 41e is turned off by the drive circuit 41g at the time of discharging, and cuts off the current flowing from the first high voltage battery 11 to the high voltage load unit 8.

The FET 41f is provided between the positive electrode of the second high voltage battery 12 and the quick charging port 20C. The FET 41f is turned on by the drive circuit 41h at the time of charging, and energizes the current flowing from the quick charging port 20C to the positive electrode of the second high voltage battery 12. Further, the FET 41f is turned off by the drive circuit 41h at the time of charging, and cuts off the current flowing back from the positive electrode of the second high voltage battery 12 to the quick charging port 20C.

The FET 41f is also arranged between the positive electrode of the second high voltage battery 12 and the high voltage load unit 8. The FET 41f is turned on by the drive circuit 41h at the time of discharging, and energizes the current flowing from the second high voltage battery 12 to the high voltage load unit 8. Further, the FET 41f is turned off by the drive circuit 41h at the time of discharging, and cuts off the current flowing from the second high voltage battery 12 to the high voltage load unit 8.

The drive circuit 41g drives and controls the FET 41e. The drive circuit 41g is connected to the control unit 50 and the FET 41e, and turns the FET 41e ON or OFF based on the control signal output from the control unit 50.

The drive circuit 41h drives and controls the FET 41f. The drive circuit 41h is connected to the control unit 50 and the FET 41f, and turns the FET 41f ON or OFF based on the control signal output from the control unit 50.

The control unit 50 controls the charging relays 41a to 41c and the drive circuits 41g and 41h. The control unit 50 is based on the monitoring result of the first high voltage battery 11 output from the BMS 13A, the monitoring result of the second high voltage battery 12 output from the BMS 14A, the detection voltage detected by the voltage monitoring unit 33, and the like. It controls the charging relays 41a to 41c and the drive circuits 41g and 41h.

FIG. 23 is a circuit diagram showing an operation example (No. 1) of the power supply system 1B according to the third embodiment when the vehicle is running. As shown in FIG. 23, the control unit 50 controls the charge switching unit 40B when supplying electric power to the motor inverter 7 having a load voltage of about 800 V (second voltage) when the vehicle is running, and the first high voltage battery A series circuit P including 11 inverters and a second high voltage battery 12 is formed. Specifically, the control unit 50 turns on the charging relays 41a, 41c and the FET 41f and turns off the charging relay 41b and the FET 41e to form the series circuit P. Then, the control unit 50 supplies electric power to the motor inverter 7 from the first high-voltage battery 11 and the second high-voltage battery 12 constituting the series circuit P through the 800V power supply line. Note that FIG. 30 illustrates the ON / OFF relationship of the charging relays 41a, 41b, 41c, FET 41e, and 41f when driving the 800V motor while the vehicle is running.

In the example shown in FIG. 23, the control unit 50 supplies power to the motor inverter 7 having a load voltage of about 800 V, and simultaneously powers the high voltage load unit 8 having a load voltage of about 400 V (first voltage). Is supplying. Specifically, the control unit 50 connects the series circuit P and the motor inverter 7 and supplies electric power to the motor inverter 7 from the first high voltage battery 11 and the second high voltage battery 12 constituting the series circuit P. At the same time, the second high-voltage battery 12 and the high-voltage load unit 8 are connected, and power is supplied to the high-voltage load unit 8 from the second high-voltage battery 12 via a 400V power supply line.

FIG. 24 is a circuit diagram showing an operation example (No. 2) of the power supply system 1B according to the third embodiment when the vehicle is running. In this example, it is assumed that the load voltages of the motor inverter 7 and the high voltage load unit 8 are both 400V. In this case, the control unit 50 controls the charge switching unit 40B to form a parallel circuit Q including the first high-voltage battery 11 and the second high-voltage battery 12. Specifically, the control unit 50 turns off the charging relay 41a and turns on the charging relays 41b and 41c and the FETs 41e and 41f to form the parallel circuit Q. Then, the control unit 50 supplies electric power to the motor inverter 7 and the high-voltage load unit 8 from the first high-voltage battery 11 and the second high-voltage battery 12 constituting the parallel circuit Q at a power supply line of 400 V. Note that FIG. 30 illustrates the ON / OFF relationship of the charging relays 41a, 41b, 41c, FET 41e, and 41f when driving the 400V motor while the vehicle is running.

FIG. 25 is a circuit diagram showing an operation example (No. 3) of the power supply system 1B according to the third embodiment when the vehicle is running. In this example, it is assumed that the load voltages of the motor inverter 7 and the high voltage load unit 8 are both 400 V, and an abnormality has occurred in the high voltage load unit 8. In this case, the control unit 50 stops the power supply to the abnormal high voltage load unit 8 and continues the power supply to the motor inverter 7 on the 400V power supply line. Specifically, the control unit 50 turns off the charging relay 41c and the FET 41f in the state of the parallel circuit Q in FIG. 24 to stop the power supply from the second high-voltage battery 12 to the high-voltage load unit 8. The FET 41e is turned off to stop the power supply from the first high voltage battery 11 to the high voltage load unit 8 (see FIG. 25). As a result, the power supply system 1B can continue to supply power to the motor inverter 7 in a state where the power supply to the high voltage load unit 8 is stopped, and the influence on the traveling motor of the vehicle (the power supply voltage is sudden). (Drop, etc.) can be suppressed, and a decrease in reliability during vehicle running can be suppressed.

FIG. 26 is a circuit diagram showing an operation example of the power supply system 1B according to the third embodiment at the time of ultra-rapid charging. For example, when performing ultra-rapid charging (for example, 800V charging), the control unit 50 controls the charging switching unit 40B to form the series circuit P. For example, as shown in FIG. 26, the control unit 50 turns on the charging relay 41a and the FET 41e and turns off the charging relays 41b, 41c and the FET 41f to form the series circuit P. Then, the power supply system 1B turns on the main switching unit 32C, electrically connects the series circuit P and the quick charging port 20C, and supplies the power supplied from the quick charging port 20C to the first high voltage in the 800V power supply line. The voltage battery 11 and the second high voltage battery 12 are charged. Note that FIG. 30 illustrates the ON / OFF relationship of the charging relays 41a, 41b, 41c, FET 41e, and 41f in ultra-rapid charging (800V charging).

FIG. 27 is a circuit diagram showing an operation example (No. 1) of the power supply system 1B according to the third embodiment during rapid charging. For example, when performing quick charging (for example, 400V charging), the control unit 50 controls the charging switching unit 40B to form the parallel circuit Q. For example, as shown in FIG. 27, the control unit 50 turns on the charging relays 41b and 41c and the FETs 41e and 41f and turns off the charging relay 41a to form the parallel circuit Q. Then, the power supply system 1B turns on the main switching unit 32C, electrically connects the parallel circuit Q of the charging switching unit 40B and the quick charging port 20C, and supplies the power supplied from the quick charging port 20C to the power supply line of 400V. Charges the first high-voltage battery 11 and the second high-voltage battery 12 with. Note that FIG. 30 illustrates the ON / OFF relationship of the charging relays 41a, 41b, 41c, FET 41e, and 41f in quick charging (400V charging).

FIG. 28 is a circuit diagram showing an operation example (No. 2) of the power supply system 1B according to the third embodiment during rapid charging. For example, when the charge amounts of the first and second high-voltage batteries 11 and 12 are biased, the control unit 50 needs to preferentially charge one of the batteries to eliminate the bias. For example, as shown in FIG. 28, when the second high-voltage battery 12 has a smaller charge amount than the first high-voltage battery 11, the control unit 50 turns on the charging relays 41c and FET 41f and turns on the charging relays 41a, 41b and Turn off the FET 41e. Then, in the power supply system 1B, the main switching unit 32C is turned on, the second high voltage battery 12 and the quick charging port 20C are electrically connected, and the power supplied from the quick charging port 20C is connected to the power supply line of 400V. 2 Charge the high voltage battery 12. At this time, in the power supply system 1B, since the first high voltage battery 11 and the quick charging port 20C are not electrically connected, the power supplied from the quick charging port 20C is not charged to the first high voltage battery 11. The power supply system 1B may be controlled to eliminate the bias in the battery charge amount not only in the above-mentioned rapid charging but also in the regenerative operation for recovering energy when the vehicle is decelerated.

FIG. 29 is a flowchart showing an operation example at the time of quick charging of the power supply system 1B according to the third embodiment. As shown in FIG. 29, the control unit 50 confirms that all the switches are OFF (step G1). Next, the control unit 50 acquires the charge rate (SOC; System of Charge) of the first and second high-voltage batteries 11 and 12 (step G2). Next, the control unit 50 determines whether or not the charge rate of the first high-voltage battery 11 and the charge rate of the second high-voltage battery 12 are equivalent (step G3). When the charge rate of the first high voltage battery 11 and the charge rate of the second high voltage battery 12 are equal (step G3; Yes), the control unit 50 forms the parallel circuit Q and forms the first and second high voltage. The batteries 11 and 12 are charged (step G4). On the other hand, when the charge rate of the first high-voltage battery 11 and the charge rate of the second high-voltage battery 12 are not equal (step G3; No), the control unit 50 has the charge rate of the second high-voltage battery 12 first. It is determined whether or not the battery is lower than the high voltage battery 11 (step G5). When the charge rate of the second high-voltage battery 12 is lower than that of the first high-voltage battery 11 (step G5; Yes), the control unit 50 does not charge the first high-voltage battery 11 as shown in FIG. 28. , The second high voltage battery 12 is charged (step G6). On the other hand, when the charge rate of the first high voltage battery 11 is lower than that of the second high voltage battery 12 (step G5; No), the control unit 50 does not charge the second high voltage battery 12 and does not charge the second high voltage battery 12. The battery 11 is charged (step G7).

FIG. 31 is a circuit diagram showing the diode operation of the FETs 41e and 41f according to the third embodiment. FIG. 32 is a diagram showing the diode operation of the FETs 41e and 41f according to the third embodiment. As shown in FIGS. 31 and 32, the control unit 50 monitors the voltage Vbat of the first and second high-voltage batteries 11 and 12 and the charging voltage Vchr applied from the quick charging port 20C, and monitors the first and second high-voltage batteries Vchr. 2 When the voltage Vbat of the high voltage batteries 11 and 12 is smaller than the charging voltage Vchr, the FETs 41e and 41f are turned on, and when the voltage Vbat of the first and second high voltage batteries 11 and 12 is larger than the charging voltage Vchr, the FET 41e , 41f is turned off. As a result, the control unit 50 can flow the charging current Ichr from the quick charging port 20C to the first and second high voltage batteries 11 and 12, and rapidly from the positive electrodes of the first and second high voltage batteries 11 and 12. The current flowing back to the charging port 20C can be cut off.

FIG. 33 is a circuit diagram showing a charge rate equalization process according to the third embodiment. FIG. 34 is a circuit diagram showing a configuration example of the constant current circuit according to the third embodiment. FIG. 35 is a sequence chart showing the charge rate equalization processing according to the third embodiment. The control unit 50 equalizes the charge rates of the first high-voltage battery 11 and the second high-voltage battery 12 when the vehicle is running or when the battery is not charged. For example, as shown in FIG. 33, the control unit 50 forms a parallel circuit Q by turning on the charging relays 41b and 41c and turning off the charging relay 41a, and bidirectional constant current control is performed by the FETs 41e and 41f. Do. The FET 41e adjusts the current flowing from the first high voltage battery 11 to the second high voltage battery 12. The FET 41f adjusts the current flowing from the second high voltage battery 12 to the first high voltage battery 11. Note that FIG. 30 illustrates the ON / OFF relationship of the charging relays 41a, 41b, 41c, FETs 41e, and 41f in battery voltage equalization.

The drive circuits 41g and 41h are configured to include a comparison circuit 41i (see FIG. 34). The comparison circuit 41i is a result of comparing the detection voltage Vsens obtained by converting the current value of the current flowing between the first high-voltage battery 11 and the second high-voltage battery 12 into a voltage value and a predetermined reference voltage Vref. The gate signals Sig1 and Sig2 are output to the FETs 41e and 41f based on the above.

For example, as shown in FIG. 35, when the voltage V1 of the first high-voltage battery 11 is higher than the voltage V2 of the second high-voltage battery 12 at time t1, the comparison circuit 41i outputs the gate signal Sig2 to the FET 41f. , The FET 41f is completely turned on. Then, the comparison circuit 41i outputs a gate signal Sigma1 having a lower ON voltage than the gate signal Sigma2 to the FET 41e, performs constant current control (voltage equalization) by the FET 41e, and performs constant current control (voltage equalization) from the first high voltage battery 11 to the second high voltage. The charging current Ia flowing through the battery 12 is made constant. When the voltage V1 of the first high-voltage battery 11 and the voltage V2 of the second high-voltage battery 12 become equivalent at time t2, the comparison circuit 41i completely turns on the FET 41e to complete the voltage equalization process. ..

As described above, in the power supply system 1B, when the control unit 50 supplies power to the high voltage load unit 8 of 400 V, the control unit 50 controls the charge switching unit 40B to form the parallel circuit Q, and the first high voltage battery 11 And the second high-voltage battery 12 supplies power to the high-voltage load unit 8 of 400 V. When supplying electric power to the 800V motor inverter 7, the control unit 50 controls the charging switching unit 40B to form a series circuit P, and the first high voltage battery 11 and the second high voltage battery 12 to the 800V motor inverter. Power 7 is supplied. With this configuration, the power supply system 1B does not require a DC / DC converter when using two power supply voltages of 400V and 800V, and can supply both power supply voltages to the load unit by switching the switch. As a result, the power supply system 1B can simplify the system configuration and improve versatility.

Further, in the power supply system 1B, the control unit 50 controls the charge switching unit 40B to form a series circuit P, and has a voltage of about 800 V from the first high voltage battery 11 and the second high voltage battery 12 to the motor inverter 7. Power is supplied, and power having a voltage of about 400 V is supplied from the second high voltage battery 12 to the high voltage load unit 8. With this configuration, the power supply system 1B can supply a power supply voltage of 800 V and a power supply voltage of 400 V to the respective load units at the same time.

Further, in the power supply system 1B, the charge switching unit 40B includes the FET 41e that adjusts the current flowing from the first high voltage battery 11 to the second high voltage battery 12 when the parallel circuit Q is formed, and the second high voltage battery 12 The FET 41f that adjusts the current flowing through the first high voltage battery 11 is included. With this configuration, the power supply system 1B can perform constant current control by the FETs 41e and 41f. As a result, when the parallel circuit Q is formed, the power supply system 1B can suppress the flow of an excessive current due to the potential difference between the first high voltage battery 11 and the second high voltage battery 12, and the voltage of the battery. Equalization can be performed properly. Since the power supply system 1B can equalize the voltage of the battery without using a resistor or the like that limits the current, the number of parts can be reduced. As a result, the power supply system 1B can suppress the increase in size of the system and the manufacturing cost.

[Fourth Embodiment]
Next, the power supply system 1C according to the fourth embodiment will be described. In the fourth embodiment, the same components as those in the first to third embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. FIG. 36 is a perspective view showing a configuration example of the battery unit 70 according to the fourth embodiment. FIG. 37 is a circuit diagram showing a configuration example of the battery unit 70 according to the fourth embodiment. FIG. 38 is a block diagram showing a configuration example of the power supply system 1C according to the fourth embodiment.

As shown in FIG. 38, the power supply system 1C includes a battery management controller (master ECU) BM, a load power switching unit 31D, a main switching unit 32C, a quick charging port 20C, and a plurality of battery units 70. The power supply system 1C is configured by connecting a plurality of battery units 70 in series, and supplies a power supply having a voltage corresponding to the specifications of various high-voltage load units (motors for traveling, etc.). The power supply system 1C supplies a voltage of 800 V by forming a series circuit P in which the first and second high voltage batteries 11 and 12 are connected in series in each battery unit 70, for example. Further, the power supply system 1C supplies a voltage of 400 V by forming a parallel circuit Q in which the first and second high voltage batteries 11 and 12 are connected in parallel in each battery unit 70. The power supply system 1C forms a series circuit P or a parallel circuit Q according to the input voltage input from the external charger to charge the first and second high voltage batteries 11 and 12.

The battery management controller BM controls a plurality of battery units 70. The battery management controller BM is communicably connected to each battery unit 70, acquires a current value and a voltage value from each battery unit 70, and is a control signal for controlling the charging relays 41a, FET 41m, and 41n of each battery unit 70. Is transmitted to each battery unit 70. Further, the battery management controller BM controls the main switching unit 32C to turn on / off the electrical connection with the quick charging port 20C, controls the load power switching unit 31D, and electrically connects with the high voltage load unit 8. Turn the connection on and off.

As shown in FIGS. 36 and 37, each battery unit 70 includes a first high-voltage battery 11, a second high-voltage battery 12, and a battery power distribution device 71. The battery power distribution device 71 is connected to the first and second high voltage batteries 11 and 12, and distributes electric power to the first and second high voltage batteries 11 and 12. The battery power distribution device 71 is mounted on the upper surfaces of the first and second high voltage batteries 11 and 12. The battery power distribution device 71 includes a positive electrode terminal g1 and a negative electrode terminal g2 as a first input unit, charging relays 41a, FET 41m and FET 41n as switching units, current detection units 42 and 43, and voltage monitoring units 34A and 34B. It includes a control unit 50.

The positive electrode terminal g1 is connected to the positive electrode of the first high voltage battery 11, and the negative electrode terminal g2 is connected to the negative electrode of the second high voltage battery 12. The positive electrode terminal g1 is connected to the negative electrode terminal g2 of the other battery power distribution device 71, and the negative electrode terminal g2 is connected to the positive electrode terminal g1 of the other battery power distribution device 71.

The charging relay 41a forms a series circuit P, and is provided between the positive electrode of the second high voltage battery 12 and the negative electrode of the first high voltage battery 11. The charging relay 41a energizes or cuts off the current flowing from the second high voltage battery 12 to the first high voltage battery 11.

The FET 41m forms a parallel circuit Q (see FIG. 39), and is provided between the negative electrode and the negative electrode terminal g2 of the first high voltage battery 11. The FET 41m energizes or cuts off the current flowing from the negative electrode of the first high voltage battery 11 to the negative electrode terminal g2.

The FET 41n forms a parallel circuit Q, and is provided between the positive electrode terminal g1 and the positive electrode of the second high voltage battery 12. The FET 41n energizes or cuts off the current flowing from the positive electrode terminal g1 to the positive electrode of the second high voltage battery 12.

The current detection unit 42 is provided between the positive electrode terminal g1 and the positive electrode of the first high voltage battery 11, and detects the current flowing from the positive electrode terminal g1 to the first high voltage battery 11. The current detection unit 42 outputs the detected current to the control unit 50.

The current detection unit 43 is provided between the negative electrode of the second high voltage battery 12 and the negative electrode terminal g2, and detects the current flowing from the second high voltage battery 12 to the negative electrode terminal g2. The current detection unit 43 outputs the detected current to the control unit 50.

The voltage monitoring unit 34A detects the voltage of each battery cell constituting the first high voltage battery 11. The voltage monitoring unit 34A outputs the detected voltage to the control unit 50.

The voltage monitoring unit 34B detects the voltage of each battery cell constituting the second high voltage battery 12. The voltage monitoring unit 34B outputs the detected voltage to the control unit 50.

The control unit 50 controls the charging relays 41a, FETs 41m, and 41n based on the detection results output from the current detection units 42, 43 and the voltage monitoring units 34A, 34B. In each battery unit 70, when the input voltage is 400V, the control unit 50 controls the charging relays 41a, FETs 41m, and 41n to form a parallel circuit Q, and supplies the power supplied from the external charger to the first and second batteries. Charge the high-voltage batteries 11 and 12. When the input voltage is 800V, the control unit 50 controls the charging relays 41a, FETs 41m, and 41n to form a series circuit P, and uses the power supplied from the external charger as the first and second high-voltage batteries 11. , 12 to charge.

FIG. 39 is a schematic view showing a configuration example of the battery unit 70 according to the fourth embodiment. In the battery unit 70 shown in FIG. 39, both the first high-voltage battery 11 and the second high-voltage battery 12 are in a fully charged state, and the charging rates are the same. FIG. 40 is a schematic view showing overcurrent suppression (No. 1) at the time of parallel connection according to the fourth embodiment. In the battery unit 70 shown in FIG. 40, the charge rate of the first high voltage battery 11 is higher than the charge rate of the second high voltage battery 12, and the potential difference between the first high voltage battery 11 and the second high voltage battery 12 Is occurring. In this case, the control unit 50 energizes the FET 41m by completely turning it on, and performs constant current control (voltage equalization) by the FET 41n, so that the current flowing from the first high voltage battery 11 to the second high voltage battery 12 Make Ib constant.

FIG. 41 is a schematic view showing overcurrent suppression (No. 2) at the time of parallel connection according to the fourth embodiment. In the battery unit 70 shown in FIG. 41, the charge rate of the second high voltage battery 12 is higher than the charge rate of the first high voltage battery 11, and the potential difference between the first high voltage battery 11 and the second high voltage battery 12 Is occurring. In this case, the control unit 50 energizes the FET 41n by completely turning it on, and performs constant current control (voltage equalization) by the FET 41m, and the current flowing from the second high voltage battery 12 to the first high voltage battery 11 Make Ic constant.

FIG. 42 is a flowchart showing overcurrent suppression at the time of parallel connection according to the fourth embodiment. The battery management controller BM confirms that the main switching unit 32C and the load power switching unit 31D are OFF (step H1). Next, in each battery power distribution device 71, the control unit 50 acquires the voltages of the first and second high voltage batteries 11 and 12 (step H2), and the voltage of the first high voltage battery 11 is the second high voltage battery. It is determined whether or not the voltage is larger than the voltage of 12 (step H3). When the voltage of the first high voltage battery 11 is larger than the voltage of the second high voltage battery 12 (step H3; Yes), the control unit 50 sets the control unit 50 in the parallel circuit Q as shown in FIG. 40. The FET 41m is completely turned on (step H4), constant current control (voltage equalization) is performed by the FET 41n (step H5), and the current Ib flowing from the first high voltage battery 11 to the second high voltage battery 12 is made constant.

On the other hand, when the voltage of the first high voltage battery 11 is smaller than the voltage of the second high voltage battery 12 (step H3; No), the control unit 50 has the parallel circuit Q as shown in FIG. In, the FET 41n is completely turned on (step H6), constant current control (voltage equalization) is performed by the FET 41m (step H7), and the current Ic flowing from the second high voltage battery 12 to the first high voltage battery 11 is made constant. To do. In this way, in each battery power distribution device 71, the control unit 50 performs constant current control to prevent the peripheral components and the battery itself from failing due to an overcurrent when the parallel circuit Q is formed.

FIG. 43 is a schematic view showing an operation example at the time of battery failure according to the fourth embodiment. The control unit 50 determines a failure (decrease in output voltage, etc.) of the first and second high-voltage batteries 11 and 12 based on the detection results output from the voltage monitoring units 34A and 34B and the current detection units 42 and 43. .. When one of the first high-voltage battery 11 and the second high-voltage battery 12 fails, the control unit 50 electrically sets the failed battery because the failed battery may adversely affect the other normal battery. Detach and power with a normal battery. For example, as shown in FIG. 43, when the first high voltage battery 11 fails, the control unit 50 turns off the FET 41m, electrically disconnects the failed first high voltage battery 11, and performs a normal second high voltage. Power is supplied by the battery 12. Thereby, the power supply system 1C can improve the reliability.

FIG. 44 is a flowchart showing an operation example at the time of battery failure according to the fourth embodiment. The control unit 50 determines whether or not the parallel circuit Q is formed (step J1). When the parallel circuit Q is formed (step J1; Yes), the control unit 50 determines whether or not the first high-voltage battery 11 has failed (step J2). When the first high-voltage battery 11 has failed (step J2; Yes), the control unit 50 turns off the FET 41m (step J3), electrically disconnects the failed first high-voltage battery 11, and performs a normal first. 2 Power is supplied by the high voltage battery 12 (see FIG. 43). On the other hand, when the first high-voltage battery 11 has not failed (step J2; No), the control unit 50 determines whether or not the second high-voltage battery 12 has failed (step J4). When the second high-voltage battery 12 has failed (step J4; Yes), the control unit 50 turns off the FET 41n (step J5), electrically disconnects the failed second high-voltage battery 12, and performs a normal second high-voltage battery 12. 1 Power is supplied by the high voltage battery 11. When the first and second high-voltage batteries 11 and 12 have not failed (step J4; No), the control unit 50 supplies power to the first and second high-voltage batteries 11 and 12 constituting the parallel circuit Q. To do.

In step J1 described above, when the control unit 50 does not form the parallel circuit Q, that is, when the series circuit P is formed (step J1; No), whether or not the first high voltage battery 11 has failed. (Step J6). When the first high-voltage battery 11 has failed (step J6; Yes), the control unit 50 turns off the charging relay 41a and the FET 41m (step J7), turns on the FET 41n (step J8), and fails the first. The high-voltage battery 11 is electrically disconnected, and power is supplied by the normal second high-voltage battery 12. On the other hand, when the first high-voltage battery 11 has not failed (step J6; No), the control unit 50 determines whether or not the second high-voltage battery 12 has failed (step J9). When the second high-voltage battery 12 has failed (step J9; Yes), the control unit 50 turns off the charging relay 41a and the FET 41n (step J10), turns on the FET 41m (step J11), and fails the second. The high-voltage battery 12 is electrically disconnected, and power is supplied by the normal first high-voltage battery 11. When the first and second high-voltage batteries 11 and 12 have not failed (step J9; No), the control unit 50 supplies power to the first and second high-voltage batteries 11 and 12 constituting the series circuit P. To do.

As described above, the power supply system 1C includes a plurality of battery units 70 having a first high-voltage battery 11, a second high-voltage battery 12, and a battery power distribution device 71. Each of the plurality of battery units 70 is connected in series. In each battery unit 70, when the input voltage is 400V, the control unit 50 controls the charging relays 41a, FETs 41m, and 41n to form a parallel circuit Q, and supplies power supplied from the external charger to the first and first batteries. 2 Charge the high-voltage batteries 11 and 12. When the input voltage is 800V, the control unit 50 controls the charging relays 41a, FETs 41m, and 41n to form a series circuit P, and uses the power supplied from the external charger as the first and second high-voltage batteries 11. , 12 to charge. With this configuration, since the power supply system 1C has a battery changeover switch (charging relay 41a, FET 41m, 41n) for each battery unit 70, the battery unit 70 can be used even for vehicles having different battery capacities (number of battery units 70). It can be flexibly adapted by changing the number of connections, and versatility can be improved. Further, since the power supply system 1C has a battery changeover switch for each battery unit 70, it is possible to apply a battery changeover switch having a withstand voltage lower than that of the conventional battery changeover switch, and the manufacturing cost can be suppressed.

[Modification example]
Next, modifications of the first to fourth embodiments will be described. The power supply system 1 has described an example in which the input voltage input via the DC charging port 20A is about 400V or about 800V, but the present invention is not limited to this, and other voltages may be used.

Although the example in which the power storage unit 10 includes two batteries (first high voltage battery 11 and second high voltage battery 12) has been described, the present invention is not limited to this, and three or more batteries may be provided.

The control unit 50 connects the quick charger 2 or the ultra-rapid charger 3 to the DC charging port 20A, and before supplying power from the quick charger 2 or the ultra-rapid charger 3 to the DC charging port 20A, the control unit 50 is a charging relay. The example of detecting the failure of 41a to 41c has been described, but the present invention is not limited to this, and the failure may be detected at other timings.

The control unit 50 is a voltage applied to the series circuit P by the first high voltage battery 11 and the second high voltage battery 12 (detection voltage V3), and a voltage between the positive and negative electrodes of the first high voltage battery 11 (detection voltage). An example of detecting a failure of the charging relay 41a based on the voltage (detection voltage V2) between the positive voltage and the negative voltage of the second high voltage battery 12 and V1) has been described, but the present invention is not limited thereto. The control unit 50 fails the charging relay 41a based on, for example, the voltage (detection voltage V3) applied to the series circuit P by the first high voltage battery 11 and the second high voltage battery 12 and a predetermined threshold value. May be detected.

The control unit 50 is based on the voltage applied to the parallel circuit Q by the first high voltage battery 11 (detection voltage V3) and the voltage between the positive electrode and the negative electrode of the first high voltage battery 11 (detection voltage V1). An example of detecting a failure of the charging relay 41b has been described, but the present invention is not limited to this. The control unit 50 may detect a failure of the charging relay 41b based on, for example, the voltage (detection voltage V3) applied to the parallel circuit Q by the first high-voltage battery 11 and a predetermined threshold value.

The control unit 50 has a voltage (detection voltage V3) applied by the second high voltage battery 12 to the parallel circuit Q including the charging relay 41c, and a voltage (detection voltage) between the positive electrode and the negative electrode of the second high voltage battery 12. An example of detecting a failure of the charging relay 41c based on V2) has been described, but the present invention is not limited to this. The control unit 50 may detect a failure of the charging relay 41c based on, for example, the voltage (detection voltage V3) applied to the parallel circuit Q by the second high-voltage battery 12 and a predetermined threshold value.

Although the example in which the DC charging port 20A is connected to the front power supply box 30B and the AC charging port 20B is connected to the rear power supply box 30A has been described, the present invention is not limited thereto. For example, the DC charging port 20A may be configured to be connected to the rear power supply box 30A, and the AC charging port 20B may be configured to be connected to the front power supply box 30B.

The power supply system 1A has described an example in which the battery equalization process is performed via the charge switching unit 40A, but the present invention is not limited to this. The power supply system 1A may perform the battery equalization process by connecting the first high voltage battery 11 and the second high voltage battery 12 by another circuit without going through the charging switching unit 40A, for example.

The power supply system 1A has described an example of shutting off an abnormal battery via the charge switching unit 40A, but the present invention is not limited to this. The power supply system 1A may shut off the abnormal battery by another circuit, for example, without going through the charging switching unit 40A.

In the power supply system 1B, the control unit 50 controls the charging relays 41a to 41c to form a series circuit P, from the first high voltage battery 11 and the second high voltage battery 12 to the motor inverter 7 with a voltage of about 800 V. An example of supplying power and supplying power of about 400 V from the second high voltage battery 12 to the high voltage load unit 8 has been described, but the present invention is not limited to this configuration and is a substitute for the second high voltage battery 12. The first high voltage battery 11 may supply a voltage of about 400 V to the high voltage load unit 8.

1, 1A, 1B, 1C power supply system 2 Quick charger (1st external charger)
3 Ultra-quick charger (1st external charger)
4A rear inverter (load part on the rear side)
4B front inverter (load part on the front side)
6 AC power supply (second external charger)
11 1st high voltage battery (1st battery)
12 Second high voltage battery (second battery)
13 1st battery voltage detector 14 2nd battery voltage detector 20A DC charging port (1st input)
20B AC charging port (2nd input section)
30A Rear power supply box 30B Front power supply box 40, 40A Charge switching unit (switching unit)
41a Charging relay (switch for series connection)
41b Charging relay (first switch for parallel connection, switch for disconnection)
41c Charging relay (second switch for parallel connection, switch for disconnection)
41d Charging relay (switch for voltage equalization)
41e FET (first switch for constant current)
41f FET (second switch for constant current)
41m FET (switching part)
41n FET (switching part)
33A, 33B Circuit voltage detection unit 50 Control unit 70 Battery unit 100 Vehicle g1 Positive electrode terminal (first input unit)
g2 Negative electrode terminal (first input section)
P series circuit Q parallel circuit R resistor

Claims (12)

The first battery mounted on the vehicle and capable of storing electric power,
A second battery mounted on the vehicle and capable of storing electric power,
A switching unit that can be switched to a series circuit that connects the first battery and the second battery in series, or a parallel circuit that connects the first battery and the second battery in parallel.
A first input unit connected to the first external charger and inputting power supplied from the first external charger, and
A control unit that controls the switching unit based on the input voltage of the electric power input from the first input unit is provided.
When the input voltage is the first voltage, the control unit controls the switching unit to form the parallel circuit and supplies the electric power supplied from the first external charger to the first battery and the second battery. Charge and
When the input voltage is a second voltage higher than the first voltage, the switching unit is controlled to form the series circuit, and the power supplied from the first external charger is used for the first battery and the second battery. A power system characterized by charging a battery. The switching unit includes a switch for series connection forming the series circuit, a first switch for parallel connection forming the parallel circuit, and a second switch for parallel connection forming the parallel circuit. Being done
In the series circuit, the positive electrode of the first input unit and the positive electrode of the first battery are connected, and the negative electrode of the first battery and the positive electrode of the second battery are connected via the switch for series connection. The negative electrode of the second battery and the negative electrode of the first input portion are connected,
In the parallel circuit, the positive electrode of the first input unit and the positive electrode of the first battery are connected, and the negative electrode of the first battery and the negative electrode of the first input unit are connected via the first switch for parallel connection. Further, the positive electrode of the first input unit and the positive electrode of the second battery are connected via the second switch for parallel connection, and the negative electrode of the second battery and the negative electrode of the first input unit are connected. ,
When the input voltage is the first voltage, the control unit turns on the first switch for parallel connection and the second switch for parallel connection, and turns off the switch for series connection to the parallel circuit. Form and
When the input voltage is the second voltage, the series circuit is formed by turning on the switch for series connection and turning off the first switch for parallel connection and the second switch for parallel connection. The power supply system according to 1. A circuit capable of detecting the voltage applied to the series circuit by the first battery and the second battery, the voltage applied to the parallel circuit by the first battery, and the voltage applied to the parallel circuit by the second battery. Voltage detector and
A first battery voltage detector capable of detecting a voltage between the positive electrode and the negative electrode of the first battery,
A second battery voltage detector capable of detecting the voltage between the positive electrode and the negative electrode of the second battery is further provided.
The control unit connects the first external charger to the first input unit, and before supplying power from the first external charger to the first input unit, the circuit voltage detection unit, the first unit. Based on the detection results of the battery voltage detection unit and the second battery voltage detection unit, a failure of the series connection switch, the parallel connection first switch, and the parallel connection second switch is detected. The power supply system according to claim 2 to be detected. The control unit includes the voltages of the first battery and the second battery detected by the circuit voltage detection unit, the voltage of the first battery detected by the first battery voltage detection unit, and the second battery. A failure of the series connection switch is detected based on the voltage of the second battery detected by the voltage detection unit.
A failure of the first switch for parallel connection is detected based on the voltage of the first battery detected by the circuit voltage detection unit and the voltage of the first battery detected by the first battery voltage detection unit. And
A failure of the second switch for parallel connection is detected based on the voltage of the second battery detected by the circuit voltage detection unit and the voltage of the second battery detected by the second battery voltage detection unit. The power supply system according to claim 3. The first battery and the second battery are connected by the series circuit or the parallel circuit to form a power storage unit.
A rear power supply box provided on the rear side in the overall length direction of the vehicle to turn on / off the electrical connection between the power storage unit and the load unit on the rear side of the vehicle.
A front power supply box provided on the front side in the total length direction of the vehicle and for turning on / off the electrical connection between the power storage unit and the load unit on the front side of the vehicle is provided.
The power supply system according to any one of claims 1 to 4, wherein one of the rear power supply box and the front power supply box turns on and off the electrical connection between the first input unit and the power storage unit. It is provided with a second input unit connected to a second external charger having a lower charging voltage than the first external charger and inputting power supplied from the second external charger.
The power supply system according to claim 5, wherein the rear power supply box and the other side of the front power supply box turn on / off the electrical connection between the second input unit and the power storage unit. The switching unit is provided between the positive electrode of the first battery and the positive electrode of the second battery, and has a voltage equalization that turns on and off the electrical connection between the positive electrode of the first battery and the positive electrode of the second battery. It is configured to include a switch for conversion and a resistor connected in parallel to the switch for voltage equalization.
When equalizing the voltages of the first battery and the second battery, the control unit turns off the voltage equalization switch and uses the resistor to turn off the positive electrode of the first battery and the positive electrode of the second battery. Any one of claims 1 to 6 in which a closed circuit is formed and a current is passed through the resistance from the high potential side to the low potential side in the positive electrode of the first battery and the positive electrode of the second battery. The power supply system described in. A switch for shutting off the first battery and the second battery is provided.
When the first battery is abnormal, the control unit controls the shutoff switch to shut off the first battery, and from the second battery to the load unit on the rear side of the vehicle and the front part of the vehicle. Supply power to the load on the side,
When the second battery is abnormal, the shutoff switch is controlled to shut off the second battery, and the load on the rear side of the vehicle and the load on the front side of the vehicle from the first battery. The power supply system according to any one of claims 1 to 7, wherein power is supplied to the unit. When the control unit supplies electric power to the first load unit whose load voltage is the first voltage, the control unit controls the switching unit to form the parallel circuit, and the first battery and the second battery to the second. 1 Supply power to the load section,
When power is supplied to the second load unit whose load voltage is the second voltage, the switching unit is controlled to form the series circuit, and the power is supplied from the first battery and the second battery to the second load unit. The power supply system according to any one of claims 1 to 8. A plurality of battery units having the first battery, the second battery, the switching unit, the first input unit, and the control unit are provided.
The plurality of battery units are connected in series, respectively.
In each of the battery units, when the input voltage is the first voltage, the control unit controls the switching unit to form the parallel circuit, and the power supplied from the first external charger is used as the first voltage. When the 1 battery and the 2nd battery are charged and the input voltage is the 2nd voltage, the switching unit is controlled to form the series circuit, and the electric power supplied from the 1st external charger is used as the 1st battery. The power supply system according to any one of claims 1 to 9, wherein the battery and the second battery are charged. The switching unit includes a first switch for constant current that adjusts the current flowing from the first battery to the second battery when the parallel circuit is formed, and a current flowing from the second battery to the first battery. The power supply system according to any one of claims 1 to 6, 8 to 10, comprising a second switch for a constant current for adjusting the above. The control unit controls the switching unit to form the series circuit, supplies electric power from the first battery and the second battery to the second load unit whose load voltage is the second voltage, and The power supply system according to any one of claims 1 to 11, wherein power is supplied to the first load unit whose load voltage is the first voltage from either the first battery or the second battery.

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