JP5012962B2 - Vehicle power control device - Google Patents

Description

  The present invention relates to power control for a vehicle including a plurality of power storage devices that can be connected in parallel to an electric circuit.

  In recent years, an electric vehicle that travels by driving a motor with electric power stored in a power storage device has been put to practical use as an environment-friendly vehicle. Generally, an electric vehicle is equipped with a battery pack configured by connecting a plurality of battery cells in series as a power storage device. Therefore, when the battery cells in the battery pack are charged, if each battery cell has a variation in internal resistance, a battery cell exceeding the maximum voltage may be generated.

  Regarding this problem, Japanese Patent Application Laid-Open No. 2009-232659 (Patent Document 1) discloses that the charging start voltage of each battery cell of a battery (battery pack) is set to a lower value as the internal resistance increases, until the charging start voltage is reached A technique for discharging each battery cell is disclosed. According to the technique of Patent Document 1, even if each battery cell has a variation in internal resistance, it is possible to suppress the battery cell from exceeding the maximum voltage during battery charging.

JP 2009-232659 A

  By the way, in a vehicle that travels with the power of a motor, in order to extend the travelable distance, it is necessary to increase the capacity of the power storage device. In order to increase the capacity of the power storage device, it is conceivable to use a large number of battery packs connected in parallel. However, when a plurality of battery packs are connected in parallel, if a voltage difference between the battery packs is large, an excessive current may flow from a high voltage battery pack to a low voltage battery pack. As a result, the battery cell may be deteriorated, or a switch (such as a relay) or a harness provided between the battery packs may be damaged.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide voltages of a plurality of power storage devices in a vehicle including a plurality of power storage devices (batteries) that can be connected in parallel to an electric circuit. Is to equalize.

  A power control device according to the present invention is a vehicle power control device including an electric circuit including a capacitor and a plurality of power storage devices that can be connected in parallel to the capacitor, the positive electrode and the electric circuit of the plurality of power storage devices A first plurality of switches provided between each of the first and second switches, a plurality of second switches provided between the negative electrodes of the plurality of power storage devices and the electric circuit, and the first and second plurality of switches. A control circuit. When the voltage difference between the plurality of power storage devices exceeds a predetermined value, the control circuit maintains the first plurality of switches in the conductive state and alternately turns on the second plurality of switches. By executing the second control that maintains the plurality of switches in the conductive state and alternately turns on the first plurality of switches, the power energy of the power storage device having a high voltage among the plurality of power storage devices is obtained. It is moved to a power storage device having a low voltage through a capacitor.

Preferably, the control circuit executes the first control and the second control alternately at a predetermined cycle.
Preferably, when the control circuit switches from one control of the first control and the second control to the other control, the control circuit sets the first and second switches for a predetermined period after the one control is stopped. Both are set in a non-conductive state, and the other control is executed after a predetermined period.

  Preferably, the vehicle is a vehicle capable of charging a plurality of power storage devices using an external power source. The electric circuit is a charging circuit that converts electric power from an external power source into electric power that can be charged into a plurality of power storage devices. The capacitor is provided between a positive electrode line and a negative electrode line for supplying electric power converted by the charging circuit to the plurality of power storage devices.

  Preferably, the control circuit executes the first control or the second control with the charging circuit stopped.

  Preferably, the vehicle is a vehicle capable of traveling with the power of a motor. The electric circuit is a power conversion circuit that converts electric power of a plurality of power storage devices into electric power that can drive a motor. The capacitor is provided between a positive electrode line and a negative electrode line for supplying power from the plurality of power storage devices to the power conversion circuit.

  Preferably, the control circuit executes the first control or the second control with the power conversion circuit stopped.

  ADVANTAGE OF THE INVENTION According to this invention, in the vehicle provided with the some electrical storage apparatus which can be connected to an electric circuit in parallel, the voltage of a some electrical storage apparatus can be equalized.

1 is an overall block diagram of a vehicle. It is a functional block diagram of ECU. It is a flowchart (the 1) which shows the process sequence of ECU. It is a flowchart (the 2) which shows the process sequence of ECU. It is a figure which shows the variable n, m, X, and the change aspect of charging relay R1, R2. It is a flowchart (the 3) which shows the process sequence of ECU.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is an overall block diagram of a vehicle 100 equipped with a power control apparatus according to the first embodiment.

  Referring to FIG. 1, vehicle 100 includes a power supply device including a first power supply 110 and a second power supply 110A, a PCU (Power Control Unit) 120 that is a drive device (electric load), and a motor generator (MG). 130, a power transmission gear 140, a drive wheel 150, and an ECU (Electronic Control Unit) 300 that is a control device.

  1 shows a configuration in which one motor generator is provided, the number of motor generators is not limited to this, and a plurality of motor generators may be provided. In addition to the motor generator, an engine (not shown) may be mounted as a power source. That is, the present invention is applicable to all electric vehicles including hybrid vehicles that generate driving force by an engine and a motor generator, electric vehicles that do not have an engine, and fuel cell vehicles.

  First power supply 110 includes a battery B1, a system main relay SMR1 (hereinafter simply referred to as “SMR1”), and a charging relay R1.

  Battery B1 is configured to be chargeable / dischargeable. The battery B1 includes, for example, a secondary battery such as a lithium ion battery, a nickel metal hydride battery, or a lead storage battery, and a storage element such as an electric double layer capacitor.

  Battery B1 is connected to PCU 120 via positive electrode line PL1 and negative electrode line NL1. Battery B <b> 1 supplies power for generating driving force of vehicle 100 to PCU 120. Battery B1 stores the electric power generated by MG 130. Battery B1 outputs a voltage of about 200 volts, for example.

  The battery B1 is, for example, a battery pack configured by connecting a plurality of battery cells in series. And service plug SP1 is connected in series in the middle of this battery cell connected in series. This service plug SP1 functions as a safety switch for forcibly shutting off the circuit at the time of maintenance or the like. For example, the contact is opened when an external housing (not shown) of the battery B1 is opened. Configured.

  SMR1 includes relays SMR1P, SMR1R, SMR1N, and resistor RE1. Relays SMR1P and SMR1N have one end connected to the positive electrode and the negative electrode of battery B1, respectively, and the other end connected to positive electrode line PL1 and negative electrode line NL1 connecting first power supply 110 and PCU 120, respectively. Relay SMR1R is connected in parallel to relay SMR1P together with resistor RE1 connected in series. Relays SMR1P, SMR1R, and SMR1N are independently controlled by a control signal SE1 from ECU 300, and switch between connection and disconnection between battery B1 and PCU 120.

  The resistor RE1 functions as a current reducing resistor for reducing an inrush current that flows suddenly to charge the capacitor C1 when the SMR1 is turned on (turned on). When turning on SMR1, relays SMR1N and SMR1R are first turned on. Then, after capacitor C1 is charged with a low current, relay SMR1P is turned on and relay SMR1R is turned off (deenergized).

  Charging relay R1 includes relays R1P and R1N. Relays R1P and R1N have one end connected to the positive electrode and the negative electrode of battery B1, respectively, and the other end connected to positive electrode line PL2 and negative electrode line NL2 connecting first power supply 110 and charging device 200, respectively. Charging relay R1 is independently controlled by control signal SE2 from ECU 300, and switches between connection and disconnection between battery B1 and charging device 200.

  Charging relay R1 is turned on in the case of external charging in which battery B1 is charged with power from external power supply 500. The charging relay R1 can be provided outside the first power supply 110. However, when the vehicle 100 is running, the charging relay R1 is connected to the charging path outside the first power supply 110 from the positive line PL1 and the negative line NL1. In order to prevent the voltage from being applied, it is desirable to provide the charging relay R <b> 1 inside the first power supply 110.

The second power supply 110 </ b> A is connected to the PCU 120 in parallel with the first power supply 110. The second power source 110 </ b> A is also connected to the charging device 200 in parallel with the first power source 110. Second power supply 110A includes a battery B2, a system main relay SMR2 (hereinafter simply referred to as “SMR2”), and a charging relay R2. SMR2 includes relays SMR2P, SMR2R, SMR2N, and resistor RE2. The configuration and function of battery B2, relays SMR2P, SMR2R, SMR2N, resistor RE2, and charging relay R2 are the same as those of battery B1, relays SMR1P, SMR1R, SMR1N, resistor RE1, and charging relay R1, respectively. Relays SMR2P, SMR2R, and SMR2N are independently controlled by a control signal SE3 from ECU 300 to switch between connection and disconnection between battery B2 and PCU 120. Charging relay R 2 is independently controlled by a control signal SE4 from ECU 300, switching between the blocking and the connection between the charging device 200 and the battery B2.

  PCU 120 includes a converter 121, an inverter 122, and capacitors C1 and C2.

  Converter 121 is connected to positive electrode line PL1 and negative electrode line NL1, and to positive electrode line HPL and negative electrode line NL1. Converter 121 is controlled by control signal PWC from ECU 300, and performs voltage conversion between positive electrode line PL1 and negative electrode line NL1, and positive electrode line HPL and negative electrode line NL1.

  Inverter 122 is connected to converter 121 via positive line HPL and negative line NL1. Inverter 122 is controlled by control signal PWI from ECU 300 and converts the DC power supplied from converter 121 into AC power for driving MG 130. Inverter 122 also converts AC power generated by MG 130 into DC power that can charge batteries B1 and B2.

  Capacitor C1 is connected between positive line PL1 and negative line NL1, and reduces voltage fluctuation between positive line PL1 and negative line NL1. Capacitor C2 is connected between positive electrode line HPL and negative electrode line NL1, and reduces voltage fluctuation between positive electrode line HPL and negative electrode line NL1.

  MG 130 is an AC rotating electric machine, for example, a permanent magnet type synchronous motor including a rotor in which permanent magnets are embedded.

  The output torque of MG 130 is transmitted to drive wheel 150 via power transmission gear 140 configured by a speed reducer and a power split mechanism, and causes vehicle 100 to travel. MG 130 can generate power by the rotational force of drive wheel 150 during regenerative braking operation of vehicle 100. Then, the generated power is converted by the PCU 120 into charging power for the power supply devices (batteries B1 and B2).

  Furthermore, the vehicle 100 includes voltage sensors 112 and 112A. The voltage sensor 112 detects the voltage V1 of the battery B1. Voltage sensor 112A detects voltage V2 of battery B1. Each of these sensors outputs a detection result to ECU 300.

  ECU 300 includes a CPU (Central Processing Unit) and a memory (not shown in FIG. 1), and generates a control signal for controlling each device based on information stored in the memory or a signal from each sensor or the like. To do. ECU 300 controls vehicle 100 and each device by outputting the generated control signal to each device. These controls are not limited to processing by software, but can also be processed by dedicated hardware (electronic circuit).

  In FIG. 1, ECU 300 is shown as one unit, but it may be divided into two or more units depending on the function and the control target.

  Furthermore, vehicle 100 includes a charging device 200 and an inlet 220 as a configuration for charging batteries B1, B2 with electric power from outside the vehicle.

  Inlet 220 is provided in the body of vehicle 100 in order to receive AC power from external power supply 500. A charging connector 410 of the charging cable 400 is connected to the inlet 220. Then, the plug 420 of the charging cable 400 is connected to the outlet 510 of the external power source 500 (for example, a commercial power source), so that the AC power from the external power source 500 passes through the electric wire portion 430 of the charging cable 400. Transmitted to the vehicle 100. In addition, an interruption device 440 for switching between supply and interruption of electric power from the external power supply 500 to the vehicle 100 is inserted in the electric wire portion 430 of the charging cable 400.

Charging device 200 includes a charging circuit 210 and capacitors C3 and C4.
Charging circuit 210 is connected to inlet 220 via positive lines ACL1 and ACL2. Charging circuit 210 is connected to charging relay R1 through positive line PL2 and negative line NL2. Charging circuit 210 is also connected to charging relay R2 via a positive line branched from positive line PL2 and a negative line branched from negative line NL2.

  The charging circuit 210 is controlled by a control signal PWE from the ECU 300, and converts AC power supplied from the inlet 220 into DC power capable of charging the batteries B1 and B2.

  Capacitor C3 is connected between positive line PL2 and negative line NL2, and reduces voltage fluctuation between positive line PL2 and negative line NL2. In addition, since the capacitor C3 is not used during normal driving, the chargeable capacity of the capacitor C3 can be made smaller than the chargeable capacity of the capacitor C1. Capacitor C4 is connected between positive lines ACL1 and ACL2.

  By the way, when the batteries B1 and B2 are left unused for a long time or when one of the batteries B1 and B2 is replaced with a new one, a voltage difference ΔV between the voltage V1 of the battery B1 and the voltage V2 of the battery B2. May occur. If the batteries B1 and B2 are connected in parallel with the voltage difference ΔV exceeding the allowable value, a short circuit between the batteries B1 and B2 occurs.

  Therefore, when voltage difference ΔV is larger than a predetermined value, ECU 300 controls charging relays R1 and R2 to equalize voltage V1 of battery B1 and voltage V2 of battery B2 (hereinafter referred to as “equalization control”). Execute).

  FIG. 2 is a functional block diagram of a portion related to equalization control of the ECU 300. Each functional block shown in FIG. 2 may be realized by hardware processing using an electronic circuit or the like, or may be realized by software processing such as execution of a program.

ECU 300 includes a setting unit 310 and a control unit 320.
Setting unit 310 sets variables n, m, and X in accordance with a predetermined rule (described later), and outputs variables m and X to control unit 320 as parameters for controlling charging relays R1 and R2. In the following description, the variables n, m, and X are all assumed to be integers of 0 or more. A specific method for setting the variables m and X will be described later with reference to FIGS.

  Control unit 320 uses variables m and X and voltages V1 and V2 to generate control signals SE2 and SE4 so as to equalize voltage V1 and voltage V2, and outputs them to charging relays R1 and R2. A specific control method of the charging relays R1 and R2 will be described later.

  FIG. 3 is a flowchart showing a processing procedure of ECU 300 for realizing the function of setting unit 310 (setting of variables m and X). The flowchart shown below is repeatedly executed at a predetermined cycle. In addition, each step of the flowchart shown below (hereinafter, “step” is abbreviated as “S”) may be realized by hardware processing as described above, or may be realized by software processing.

In S10, ECU 300 determines whether or not variable n has reached upper limit K.
If variable n has not yet reached upper limit value K ( NO in S10), ECU 300 increases variable n by “1” in S11, and maintains the value of variable m in S12.

On the other hand, if the variable n has reached the upper limit value K (YES at S10), ECU 300 resets the variable n to an initial value "0" at S13, increased by "1" the variable m at S12 Let

  After the processing of S12 or S14, the ECU 300 increases the variable X by “1” in S15. Note that the latest values of the variables n, m, and X are stored in a memory inside the ECU 300.

  FIG. 4 is a flowchart showing a processing procedure of ECU 300 for realizing the function of control unit 320. The flowchart shown in FIG. 4 is executed at a predetermined cycle after a predetermined start condition is satisfied. The start condition can be, for example, a condition that external charging is completed, or a condition that a drive system activation request is made after the drive system has been stopped for a long period of time. In any case, it is not necessary to drive the charging circuit 210, the converter 121, and the inverter 122. In the following, it is assumed that the flowchart shown in FIG. 4 is executed with the charging circuit 210, the converter 121, and the inverter 122 stopped.

  In S20, ECU 300 determines whether or not the state in which absolute value | V1-V2 | of the difference between voltage V1 and voltage V2 exceeds predetermined value V0 has continued for a certain period of time. If the state of | V1-V2 |> V0 continues for a certain time (YES in S20), the process proceeds to S21. Otherwise (NO in S20), this process ends.

  In S21, ECU 300 determines whether or not variable m has increased. If variable m has increased (YES in S21), the process proceeds to S22. If variable m has not increased (NO in S21), the process proceeds to S23.

  In S22, ECU 300 turns off all of relays R1P, R1N, R2P, R2N for a predetermined period. The process of S22 is temporarily performed in order to prevent a short circuit between the batteries B1 and B2 when switching between a first control and a second control, which will be described later, by the subsequent processes of S23 to S24. This is a process for providing a time for disconnecting both B2 from the charging device 200.

In S23, ECU 300 determines whether or not variable m is an odd number.
If variable m is an odd number (YES in S23), the process proceeds to S24 to S27.

  In S24, ECU 300 turns on relays R1P and R2P on the positive side of charging relays R1 and R2.

  In S25, ECU 300 determines whether or not variable X is an odd number. If variable X is an odd number (YES in S25), the process proceeds to S26. If variable X is not an odd number (NO in S25), the process proceeds to S27.

  In S26, ECU 300 turns on relay R1N on the negative side of charging relay R1, and turns off relay R2N on the negative side of charging relay R2. In this state, the battery B1 is connected to the capacitor C3 of the charging device 200.

  In S27, ECU 300 turns off relay R1N and turns on relay R2N. In this state, the battery B2 is connected to the capacitor C3 of the charging device 200.

  On the other hand, if variable m is not an odd number (NO in S23), the process proceeds to S28 to S31.

  In S28, ECU 300 turns on relays R1N and R2N on the negative side of charging relays R1 and R2.

  In S29, ECU 300 determines whether or not variable X is an odd number. If variable X is an odd number (YES in S29), the process proceeds to S30. If variable X is not an odd number (NO in S29), the process proceeds to S31.

  In S30, ECU 300 turns on relay R1P on the positive side of charging relay R1, and turns off relay R2P on the positive side of charging relay R2. In this state, the battery B1 is connected to the capacitor C3 of the charging device 200.

  In S31, ECU 300 turns off relay R1P on the positive side of charging relay R1, and turns on relay R2P on the positive side of charging relay R2. In this state, the battery B2 is connected to the capacitor C3 of the charging device 200.

  FIG. 5 is a diagram illustrating how the variables n, m, and X and the charging relays R1 and R2 change during the equalization control. FIG. 5 illustrates a case where the upper limit K is “5”.

  As shown in FIG. 5, the variable n increases by 1 at a predetermined cycle, and when the upper limit value “5” is reached, the variable n is returned to “0”. The variable m increases by 1 every time the variable n reaches the upper limit “5”. The variable X increases by 1 with the same period as the variable n. However, the variable X has no upper limit.

  When the variable m is an odd number (m = 1, 3,...), The ECU 300 alternately turns on the negative relays R1N and R2N with the increasing period of the variable X while keeping the positive relays R1P and R2P on. (Relays R1N and R2N are complementarily turned on and off). Hereinafter, this control is referred to as “first control”.

  When the variable m is not an odd number (m = 0, 2, 4,...), The ECU 300 maintains the negative relays R1N and R2N on and reverses the positive relays R1P and R2P, contrary to the first control. Are alternately turned on in increments of the variable X. Hereinafter, this control is referred to as “second control”.

  By executing the first control or the second control, the battery B1 and the battery B2 are alternately connected to the capacitor C3 of the charging apparatus 200 at an increasing period of the variable X. Thereby, the power energy of the battery with the higher voltage can be transferred to the battery with the lower voltage via the capacitor C3 without connecting the batteries B1 and B2 in parallel. For example, when the voltage V1 is higher than the voltage V2, the power energy of the battery B1 is temporarily stored in the capacitor C3 when the battery B1 and the capacitor C3 are connected, and the power of the capacitor C3 is stored when the battery B2 and the capacitor C3 are connected. It is supplied to the battery B2. Thereby, equalization with voltage V1 and voltage V2 can be achieved, preventing the short circuit between battery B1, B2. At this time, it is not necessary to drive the charging circuit 210, the converter 121, and the inverter 122, and the voltage V1 and the voltage V2 can be equalized by a relatively simple control of controlling the relay.

  Further, during the execution of the first control or the second control, one of the pair of the positive side relays R1P and R2P and the pair of the negative side relays R1N and R2N operates on / off, while the other set is on. Maintained. Therefore, the number of relay operations is reduced as compared with the case where both sets are turned on and off. Furthermore, the set kept on is switched each time the variable m increases. Therefore, the operation frequency of the relay is equalized as compared with the case where the set maintained on is fixed to one of the sets. Since each relay is controlled in such a manner as to reduce the number of operation of the relay and equalize the operation frequency, it is possible to suppress a decrease in durability of each relay.

  At the time of switching between the first control and the second control, as described above, since both the positive side relays R1P and R2P and the negative side relays R1N and R2N are turned off, both the batteries B1 and B2 are Temporarily disconnected from charging device 200. Therefore, a short circuit between the batteries B1 and B2 is prevented.

  As described above, ECU 300 according to the present embodiment maintains first positive relays R1P and R2P on, and first turns on negative relays R1N and R2N alternately, and negative relays R1N and R2N. Is switched on at a predetermined cycle (every time the variable m increases), while the second control for alternately turning on the positive-side relays R1P and R2P is maintained. As a result, the power energy of the battery having the higher voltage can be transferred to the battery having the lower voltage via the capacitor C3, so that the short circuit between the batteries B1 and B2 can be prevented and the voltage V1 and the voltage V2 can be reduced. Equalization can be achieved. Furthermore, since the number of relay operations can be reduced and the operation frequency can be equalized, the durability of each relay can be improved.

  Note that three or more batteries that can be connected in parallel may be provided. In this case, three or more relays on the other pole side may be turned on alternately while keeping all three or more relays on one pole side on. “Turn on three or more relays alternately” means that one of three or more relays is turned on (the other is turned off), and the one relay to be turned on is periodically switched in order. It means that

[Modification]
In the above-described embodiment, the energy transfer between the batteries B1 and B2 is performed via the capacitor C3 of the charging device 200. However, the energy transfer between the batteries B1 and B2 is performed via the capacitor C1 of the PCU 120. Good. In this case, the control targets of the relays R1P, R2P, R1N, and R2N in the processing of FIG. 4 described above may be changed to the relays SMR1P, SMR2P, SMR1N, and SMR2N, respectively.

  FIG. 6 is a flowchart showing a processing procedure of ECU 300 according to the modification of the embodiment. Of the steps shown in FIG. 6, the steps given the same numbers as the steps shown in FIG. 4 described above have already been described, and detailed description thereof will not be repeated here.

  In S22a, ECU 300 turns off all of relays SMR1P, SMR2P, SMR1N, and SMR2N for a predetermined period.

  In S24a, ECU 300 turns on relays SMR1P and SMR2P on the positive side of SMR1 and SMR2.

  In S26a, ECU 300 turns on relay SMR1N on the negative side of SMR1, and turns off relay SMR2N on the negative side of SMR2. In this state, the battery B1 is connected to the capacitor C1 of the PCU 120.

  In S27a, ECU 300 turns off relay SMR1N and turns on relay SMR2N. In this state, battery B2 is connected to capacitor C1 of PCU 120.

At S28 a, ECU 300 is, SMR1, the negative pole-side relay SMR1N of SMR2, turning on the SMR2N.

  In S30a, ECU 300 turns on relay SMR1P on the positive side of SMR1, and turns off relay SMR2P on the positive side of SMR2. In this state, the battery B1 is connected to the capacitor C1 of the PCU 120.

  In S31a, ECU 300 turns off relay SMR1P on the positive side of SMR1, and turns on relay SMR2P on the positive side of SMR2. In this state, the battery B2 is connected to the capacitor C1 of the PCU 120.

  If it does in this way, the electric energy of a battery with a higher voltage can be moved to a battery with a lower voltage via capacitor C1. In general, the chargeable capacity of the capacitor C1 is larger than the chargeable capacity of the capacitor C3. Therefore, compared to the case where the capacitor C3 is used, the current flowing between the batteries B1, B2 and the capacitor C1 is increased and the moving speed of the power energy is increased, so that the voltage V1 and the voltage V2 are equalized at an early stage. be able to.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 vehicle, 110 first power source, 110A second power source, 112, 112A voltage sensor, 120 PCU, 121 converter, 122 inverter, 140 power transmission gear, 150 driving wheel, 200 charging device, 210 charging circuit, 220 inlet, 300 ECU , 310 setting unit, 320 control unit, 400 charging cable, 410 charging connector, 420 plug, 430 electric wire unit, 440 disconnection device, 500 external power supply, 510 outlet, ACL1, ACL2, HPL, PL1, PL2 positive line, B1, B2 Battery, C1, C2, C3, C4 capacitor, NL1, NL2 negative line, R1P, R1N, R2P, R2N, SMR1R, SMR1N, SMR2P, SMR2N relay, R1, R2 charging relay, RE1, RE2 resistance, SMR1, SMR2 system main relay, SP1 service plug.

Claims (7)

A power control apparatus for a vehicle, comprising: an electric circuit including a capacitor; and a plurality of power storage devices connectable in parallel to the capacitor,
A plurality of first switches provided between positive electrodes of the plurality of power storage devices and the electric circuit;
A plurality of second switches respectively provided between negative electrodes of the plurality of power storage devices and the electric circuit;
A control circuit for controlling the first and second plurality of switches,
The control circuit maintains the first plurality of switches in a conducting state and alternately turns the second plurality of switches into a conducting state when a voltage difference between the plurality of power storage devices exceeds a predetermined value. By performing one control or a second control that maintains the second plurality of switches in a conductive state and alternately turns on the first plurality of switches, the voltage of the plurality of power storage devices is increased. A power control apparatus for a vehicle that moves power energy of a high power storage device to a power storage device having a low voltage through the capacitor.   The power control apparatus for a vehicle according to claim 1, wherein the control circuit alternately executes the first control and the second control at a predetermined cycle. In the case where the control circuit switches from one control of the first control and the second control to the other control, the first and second plurality of control circuits are provided for a predetermined period after the one control is stopped. The power control apparatus for a vehicle according to claim 2, wherein both the switches are set in a non-conductive state, and the other control is executed after the predetermined period has elapsed. The vehicle is a vehicle that can charge the plurality of power storage devices using an external power source,
The electric circuit is a charging circuit that converts electric power of the external power source into electric power that can be charged to the plurality of power storage devices,
4. The vehicle power control device according to claim 1, wherein the capacitor is provided between a positive electrode line and a negative electrode line for supplying electric power converted by the charging circuit to the plurality of power storage devices. 5. .   The power control apparatus for a vehicle according to claim 4, wherein the control circuit executes the first control or the second control in a state where the charging circuit is stopped. The vehicle is a vehicle that can be driven by the power of a motor,
The electric circuit is a power conversion circuit that converts electric power of the plurality of power storage devices into electric power that can drive the motor,
4. The vehicle power control device according to claim 1, wherein the capacitor is provided between a positive electrode line and a negative electrode line for supplying electric power of the plurality of power storage devices to the power conversion circuit. 5.   The power control apparatus for a vehicle according to claim 6, wherein the control circuit executes the first control or the second control in a state where the power conversion circuit is stopped.

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