JP2020058113A - Power supply system - Google Patents

Abstract

To provide a power supply system in which a fluctuation of a current in a capacity-type battery generated while the capacity-type battery and a power-type battery are connected with each other via a current wire can be minimized.SOLUTION: The power supply system includes a plurality of first storage batteries (e.g., power-type batteries), a plurality of motors that are provided so as to correspond to the plurality of first storage batteries, a plurality of inverters that are provided so as to correspond to the plurality of motors, a second storage battery (e.g., capacity-type battery) that is connected to the plurality of first storage batteries via switches and that has a capacity larger than that of each of the first storage batteries, and a control unit that controls an on/off state of each of the switches such that a fluctuation of a current regarding the second storage battery is reduced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply system, and is suitably applied to, for example, a power supply system having a first storage battery and a second storage battery having a larger capacity than the first storage battery.

  Some electric vehicles use a capacity-type battery for increasing the cruising distance and a power wheel for four wheels. Some power wheels incorporate not only a motor and an inverter but also a power type battery. In such a configuration, a thick power cable (current line) through which a large current of a high voltage can flow between the inverter and the motor is required.

  However, when a thick power cable is used, there is a problem that steering characteristics are deteriorated and other wiring is difficult.

  In this regard, in order to eliminate a thick power cable, a technique of supplying power from a capacity battery to a power battery in a power wheel by wireless power transmission is disclosed (see Patent Document 1).

WO 2013/98928

  Introduction of wireless power transmission tends to be costly. Further, in the wireless power transmission, there is a problem that power transmission efficiency is deteriorated and a cruising distance is shortened.

  Therefore, instead of eliminating the power cable, we want to make the power cable thinner.

  However, when the capacity type battery and the power type battery are connected by a thin power cable, the current cannot flow much, and even if the current flows, the current of the capacity type battery fluctuates, which leads to heat generation of the capacity type battery. There is a problem that the life of the battery is shortened.

  The present invention has been made in view of the above points, and a power supply system capable of minimizing fluctuations in the current of a capacity battery that occurs when the capacity battery and the power battery are connected by a current line. It is intended to propose.

  In order to solve this problem, in the present invention, a plurality of first storage batteries, a plurality of motors provided corresponding to the plurality of first storage batteries, and a plurality of inverters provided corresponding to the plurality of motors are provided. And a second storage battery connected to the plurality of first storage batteries via a switch and having a larger capacity than the first storage battery; and a switch connected to the second storage battery so as to reduce a change in current related to the second storage battery. And a control unit for controlling on and off.

  In the above configuration, the first storage batteries are connected to each other by a current line, and the second storage battery is connected to the first storage battery via the switch, so that the change in the current related to the second storage battery is reduced. Since ON and OFF can be controlled, for example, heat generation of the second storage battery can be avoided, and the life of the second storage battery can be extended. Further, for example, by suppressing the current of the second storage battery by controlling the switch, a thin current line can be used.

  According to the present invention, it is possible to realize a power supply system that suppresses fluctuations in the current of the second storage battery.

FIG. 1 is a diagram illustrating an example of a configuration according to an electric vehicle according to a first embodiment. FIG. 5 is a diagram illustrating an example of a flowchart according to a switch control process according to the first embodiment. FIG. 3 is a diagram illustrating an example of a configuration according to a switch according to the first embodiment. FIG. 9 is a diagram illustrating an example of a configuration according to an electric vehicle according to a second embodiment. It is a figure showing an example of a flow chart concerning switch control processing by a 2nd embodiment. FIG. 14 is a diagram illustrating an example of a configuration according to an electric vehicle according to a third embodiment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and includes various modifications and applications within the technical concept of the present invention. For example, the power supply system described below can be applied to electric vehicles such as electric vehicles, railways, drones, and robots, building management systems, construction machines, and the like.

  Hereinafter, an electric vehicle having a power wheel with a built-in power type battery will be described as an example.For example, in order to reduce the cost of the electric vehicle and suppress the life of the capacity type battery, the current of the capacity type battery is reduced. It is necessary to have a configuration that minimizes the fluctuation of the distance.

  One of the features of such a configuration is, for example, the following configuration. As control of the switch, the right switch is disconnected when the right power wheel is regenerated and the capacity type battery current becomes “0” (zero). Similarly, when the power wheel on the left side is regenerated and the capacity type battery current becomes “0”, the switch on the left side is disconnected. Next, the timing of turning on the switch is when the right power wheel is in power running and the voltage difference between the voltage of the storage battery and the voltage of the capacity type battery in the right power wheel is within the threshold value. I do. The same switch-on timing is applied to the left side.

  One of the features of such a configuration is, for example, the following configuration. The right and left power wheels are connected by a current line, and further connected to a capacity battery via a switch. Similarly, the front and rear power wheels are connected by a current line, and further connected to a capacity type battery via a switch. Then, the switching phases of the inverter carrier frequencies of the inverters in the front and rear power wheels are shifted by 180 degrees. Further, an ammeter is provided for the current line only on the right side and the current line only on the left side so that the voltage of the storage battery in each power wheel can be monitored.

  According to the above configuration, the fluctuation of the current of the capacity type battery can be suppressed as much as possible. Note that the above configuration is also an example, and the present invention is not limited to the above configuration.

  In the following description, in the case where the same type of element is described without being distinguished, a common part (a part excluding the branch number) of the reference numerals including the branch number is used to distinguish and describe the same type of element. In some cases, a reference code including a branch number may be used. For example, when the power wheels are described without particular distinction, they are described as “power wheels 110”, and when the individual power wheels are described separately, they are described as “power wheels 110FR” and “power wheels 110FL”. May be described.

(1) First Embodiment In FIG. 1, reference numeral 1 denotes a power supply system according to the first embodiment as a whole. Hereinafter, a case where the power supply system 1 which is a system related to a battery that supplies power to an electric load is applied to the electric vehicle 100 will be described.

  The electric vehicle 100 includes a plurality of power wheels 110, a capacity type battery 120, an ECU (Electronic Control Unit) 130, a switch (SW) 140, and an ammeter 150. As shown in FIG. 1, the components are connected by current lines shown by solid lines.

  The electric vehicle 100 is an electric vehicle using four power wheels 110 (front, rear, left and right). A power wheel 110FR is provided on the front right side, a power wheel 110FL is provided on the front left side, and a power wheel 110FL is provided on the rear right side. Is provided with a power wheel 110RR, and on the rear left side, a power wheel 110RL is provided.

  Each power wheel 110 includes a motor wheel 111 containing a motor (not shown), an inverter (INV) 112, and a power type battery 113. The electric vehicle 100 supplies electric power from the capacity type battery 120 to the power type battery 113 via the switch 140, and supplies electric power from the power type battery 113 to the inverter 112 to drive the motor wheel 111.

  The power type battery 113 and the capacity type battery 120 are storage batteries. The power type battery 113 is a storage battery having a smaller capacity than the capacity type battery 120. The output of the power type battery 113 with respect to the capacity (output / capacity) is higher than that of the capacity type battery 120.

  The ECU 130 receives information from the monitoring unit (current signal from the ammeter 150, current information and voltage information from the BCU (Battery Control Unit; not shown) of each power type battery 113, current of the BCU of the capacity type battery 120). Information and voltage information), and outputs a phase control signal to the inverter 112, a control signal to the switch 140, and the like. The BCU is provided, for example, in the power type battery 113, and monitors the state (charge rate, voltage, current, etc.) of the power type battery 113.

  In the present embodiment, only the right power wheels 110FR and 110RR are connected by a current line, and only the left power wheels 110FL and 110RL are connected by a current line. The reason is that when the electric vehicle 100 turns a curve, the timing of regeneration and the timing of powering are shifted only on the left side and only on the right side, so that connecting the left and right has a higher angular velocity than connecting only the front and the rear only. This is because they are aligned and phase control is easy. However, only the front and only the back may be connected by a current line.

  In the phase control, the switching phases of the inverter carrier frequencies of the front inverters 112FR and FL and the rear inverters 112RR and RL are shifted by 180 degrees. As a result, the switching noise is canceled in the front and rear inverters 112. If the rotational speeds of the front and rear tires are the same, the motor phase (rotational phase) of the motor is further shifted by 180 degrees. As a result, fluctuations (pulsations) of the current depending on the number of rotations of the motor can be suppressed. The ECU 130 and the inverter 112 are connected by a communication line indicated by a broken line in FIG.

  Next, a sequence (current control) related to the switch 140 will be described. Regarding the current control by the switch 140, the idea is to prevent the switch 140 from being turned off with a large current, not to regenerate the capacity battery 120, and to use the power battery 113 as much as possible during power running. Such current control will be described with reference to FIG.

  FIG. 2 is a diagram illustrating an example of a flowchart according to the switch control process. The switch control process illustrated in FIG. 2 is executed by a control unit (for example, software in ECU 130 (a processor reads a program into a memory and executes the program)). The switch control process starts when the electric vehicle 100 is turned on and ends when the ignition is turned off.

  First, in step S201, the ECU 130 turns on the left and right switches 140L and 140R (both switches) together with the ignition being turned on.

  Next, in step S202, the ECU 130 measures the current of the left and right ammeters 150L and 150R. Then, voltage information is received from the power type battery 113 and the capacity type battery 120 (each battery pack) via the communication line.

  Next, in step S203, the ECU 130 determines that the right switch 140R is on, the right is regenerative, and the current of the right ammeter 150R is “0” or almost “0” (a value corresponding to zero). Is determined (whether all conditions are satisfied). If the ECU 130 determines that all the conditions are satisfied, the process proceeds to step S204. If the ECU 130 determines that none of the conditions is satisfied, the process proceeds to step S205.

  Here, for example, when the sign of the current of the right ammeter 150R is on the charging side, the ECU 130 may determine that the right side is in regeneration (regeneration state), or the right power type batteries 113FR and 113RR. If the sum of the currents is the sign on the charging side, the right side may be determined to be regenerative, and if other predetermined conditions are satisfied, the right side may be determined to be regenerative. On the other hand, for example, when the sign of the current of the right ammeter 150R is on the discharge side, the ECU 130 may determine that the right side is in power running (power running state), or the right power type batteries 113FR and 113RR may be in the power running state. If the sum of the currents is the sign of the discharge side, the right side may be determined to be power running, and if other predetermined conditions are satisfied, the right side may be determined to be power running. Note that the determination on whether the left side is regenerative and the determination on whether the left side is power running are performed in the same manner as the right side.

  In step S204, the ECU 130 turns off the right switch 140R, and shifts the processing to step S205. Thereafter, regeneration is absorbed only by the power type batteries 113FR and 113RR in the right power wheels 110FR and 110RR. For this reason, the voltage of the power type batteries 113FR and 113RR in the right power wheels 110FR and 110RR increases, so that when the right switch 140R is turned on again, power running is performed (see step S209).

  In step S205, the ECU 130 determines whether the left switch 140L is on, the left is regenerative, and the current of the left ammeter 150L is “0” or almost “0” (a value corresponding to zero). It is determined whether or not all the conditions are satisfied. If the ECU 130 determines that all the conditions are satisfied, the process proceeds to step S206. If the ECU 130 determines that none of the conditions is satisfied, the process proceeds to step S207.

  In step S206, the ECU 130 turns off the left switch 140L, and moves the process to step S207. Thereafter, regeneration is absorbed only by the power type batteries 113FL and 113RL in the left power wheels 110FL and 110RL. For this reason, since the voltage of the power type batteries 113FL and 113RL in the left power wheels 110FL and 110RL increases, when the left switch 140L is turned on again, power running is performed (see step S207).

  In step S207, the ECU 130 determines that the left switch 140L is off, the left is power running, and the voltage difference between the voltage of the left power type batteries 113FL and 113RL and the voltage of the capacity type battery 120 is the threshold ε. Is determined (whether all conditions are satisfied). If the ECU 130 determines that all the conditions are satisfied, the process proceeds to step S208. If the ECU 130 determines that none of the conditions is satisfied, the process proceeds to step S209. Here, ε is set to a value which does not exceed the maximum current of the battery described in the battery catalog in advance from the switch resistance and the battery resistance when the switch is turned on, which is set in a table in advance.

  In step S208, the ECU 130 turns on the left switch 140L, and moves the process to step S209.

  In step S209, the ECU 130 determines that the right switch 140R is off, the right is power running, and the voltage difference between the voltage of the right power batteries 113FR and 113RR and the voltage of the capacity battery 120 is equal to the threshold ε. Is determined (whether all conditions are satisfied). If the ECU 130 determines that all of the conditions are satisfied, the process proceeds to step S210. If the ECU 130 determines that none of the conditions is satisfied, the process proceeds to step S202. Here, ε is set to a value which does not exceed the maximum current of the battery described in the battery catalog in advance from the switch resistance and the battery resistance when the switch is turned on, which is set in a table in advance.

  In step S210, the ECU 130 turns on the right switch 140R, and moves the process to step S202.

  In this way, by turning the switch 140 to the left and right, turning the left and right switches 140L and 140R off for each regeneration and turning on each power run, for example, from the capacity type battery 120 to the power type battery 113 in each power wheel 110 Current peaks can be suppressed. Further, for example, by preventing regeneration to the capacity type battery 120, the current line can be made thin. Further, for example, fluctuations in the current of the capacity type battery 120 can be suppressed, and the life of the capacity type battery 120 can be extended.

The above is the flow of the switch control process. Next, an example of a configuration of the switch 140 is illustrated in FIG. As the switch 140, a mechanical relay, a semiconductor type (IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal-Oxide-Semiconductor Field-Effect)
Transistor) may be used. Here, as a worst case, the switch 140 may be turned on and off even when there is a potential difference such as after the capacity type battery 120 is charged. Therefore, a mechanism for preventing an inrush current may be provided. FIG. 3 shows an example in which a power MOSFET is used as the switch 140.

  As shown in FIG. 3, the switch 140 includes four power MOSFETs 310 (power MOSFETs 310A, 310B, 310C, 310D). The power MOSFETs 310A and 310B are switches used when the potential difference is large and the current is largely estimated, and the power MOSFETs 310C and 310D are switches used when the potential difference is low or the current is cut off.

  The gate of each power MOSFET 310 is separately connected to the ECU 130. The power MOSFET 310 is turned on by an on signal of each power MOSFET 310 transmitted from the ECU 130, and the power MOSFET 310 is turned off by an off signal.

  When the potential difference is large, the resistor 320 is a resistor for connecting the power MOSFETs 310C and 310D first to limit the current when, for example, the electric vehicle 100 is started (when the motor is started).

  The capacitor 330 is a snubber capacitor for absorbing the energy of the inductance of the electric wire when the power MOSFETs 310C and 310D are turned off, for example, when the electric vehicle 100 is running (when the motor is running).

  Note that a mechanical switch may be further provided in series with the power MOSFET 310 shown in FIG. This is because the semiconductor switch has a leakage current and suppresses consumption of battery current during parking.

  When the potential difference between the capacity type battery 120 and the power type battery 113 is widened and the power MOSFETs 310C and 310D cannot be turned on, the charging rate of the power type battery 113 is reduced independently of the switch control processing of FIG. When the voltage falls below a threshold value (predetermined value, for example, 30%), the power MOSFETs 310A and 310B are kept off and the power MOSFETs 310C and 310D are turned on. , And then connect the power MOSFETs 310C and 310D.

  In other words, in the switch control process, the power MOSFETs 310A and 310B are turned on, and the on and off of the power MOSFETs 310C and 310D (switches) are controlled.

  In the above configuration, the first storage batteries (for example, the right power batteries 113FR and 113RR, and the left power batteries 113FL and 113RL) are connected by a current line, and are connected via switches (for example, switches 140L and 140R). By connecting the second storage battery (for example, the capacity type battery 120) to the first storage battery, the on and off of the switch can be controlled so as to reduce the fluctuation of the current related to the second storage battery. For example, heat generation of the second storage battery can be avoided, and the life of the second storage battery can be extended. Further, for example, by suppressing the current of the second storage battery by controlling the switch, a thin current line can be used.

(2) Second Embodiment The first embodiment is an example of a configuration in which switches 140 are provided on the left and right. However, the number of the switches 140 may be one. FIG. 4 shows an example of this configuration. The difference from FIG. 1 is that one switch 410 is used instead of the switches 140L and 140R. In this case, the difference between the left and right inner and outer wheels cannot be taken into account, but when the left side is regenerative, the right side is often power running, so current flows on the left and right, and little current flows on the capacity type battery 120. But because it is effective. In addition, about the structure same as the structure of 1st Embodiment, the description is abbreviate | omitted suitably using the same code | symbol.

  Next, a sequence (current control) related to the switch 410 will be described with reference to FIG.

  FIG. 5 is a diagram illustrating an example of a flowchart according to the switch control process. The switch control process is executed by software in the ECU 420 as in FIG. The switch control process starts when the ignition of the electric vehicle 400 is turned on and ends when the ignition is turned off.

  First, in step S501, the ECU 420 turns on the switch 410 together with the ignition on.

  Next, in step S502, the ECU 420 measures the current of the capacity type battery 120, and receives voltage information from the power type battery 113 and the capacity type battery 120 (each battery pack) via a communication line. It is assumed that the capacity type battery 120 measures a battery current measured by a built-in BCU and is flowing through a communication line. To add, an ammeter may be provided between the switch 410 and the capacity battery 120.

  Next, in step S503, the ECU 420 determines whether the switch 410 is on, the battery is regenerating as a whole, and the current of the capacity battery 120 is “0” or almost “0” (a value corresponding to zero). It is determined whether or not all the conditions are satisfied. If the ECU 420 determines that all the conditions are satisfied, the process proceeds to step S504. If the ECU 420 determines that none of the conditions is satisfied, the process proceeds to step S505.

  In step S504, ECU 420 turns off switch 410, and moves the process to step S505.

  In step S505, the ECU 420 determines whether or not the switch 410 is off, the power is running as a whole, and the voltage difference between the voltage of the power type battery 113 and the voltage of the capacity type battery 120 is less than the threshold value ε. (Whether all conditions are satisfied). If the ECU 420 determines that all the conditions are satisfied, the process proceeds to step S506, and if it is determined that at least one of the conditions is not satisfied, the process proceeds to step S502. Here, ε is set to a value which does not exceed the maximum current of the battery described in the battery catalog in advance from the switch resistance and the battery resistance when the switch is turned on, which is set in a table in advance.

  In step S506, ECU 420 turns on switch 410, and moves the process to step S502.

  When the switch 410 cannot be turned on because the potential difference between the capacity type battery 120 and the power type battery 113 widens, the charging rate of the power type battery 113 is set to a threshold value (predetermined independently of the flow of FIG. 5). (For example, 30%) or less, the power MOSFETs 310A and 310B are kept off, the power MOSFETs 310C and 310D are turned on, and the battery voltage is held constant by the current limited by the resistor 320. Then, the power MOSFETs 310C and 310D are connected.

  In the above configuration, the first storage batteries (for example, front-rear and left-right power type batteries 113FR, 113RR, 113FL, 113RL) are connected by a current line, and the second storage battery (for example, capacity) is connected via a switch (for example, switch 140). By connecting the type battery 120) to the first storage battery, current flows on the left and right, and little current flows in the second storage battery, so that fluctuations in the current of the second storage battery can be suppressed. .

(3) Third Embodiment The above is the case of one or two switches. However, in the case of an electric vehicle running in a place with many curves, three switches are required in consideration of the left / right balance and the overall balance. It may be one. FIG. 6 shows an example of this configuration. The difference from FIG. 1 lies mainly in that a switch 610 is added.

  The switch control process in the electric vehicle 600 according to the present embodiment is basically the switch control process shown in FIG. More specifically, after step S210, the ECU 620 leads to step S502 in FIG. 5. If “NO” in the determination of step S209, the ECU 620 shifts the process to step S502 instead of step S202. Transfer processing to

  In the above configuration, the right first storage batteries (for example, the right power batteries 113FR and 113RR) are connected by a current line, and the right switch (for example, the right switch 610R) and a common switch (for example, the switch). 610C), the second storage battery (for example, the capacity type battery 120) and the right first storage battery are connected, and the first storage batteries on the left side (for example, the power type batteries 113FL and 113RL on the left side) are connected. Since the second storage battery and the first storage battery on the right side are connected via a current line and connected via a switch on the left side (for example, the switch 610L on the left side) and a common switch, the balance between the left and right sides and the overall balance are maintained. For example, when the vehicle runs in a place with many curves, fluctuations in the current of the second storage battery can be suppressed.

(4) Other Embodiments In the above-described embodiment, a case has been described in which the present invention is applied to a power supply system. However, the present invention is not limited to this, and various other systems and devices may be used. , Methods and programs.

  Further, in the above-described embodiment, the electric vehicle 100 using the power wheel 110 for four wheels has been described as an example. However, the present invention is not limited to this. Alternatively, the present invention may be applied to an electric vehicle used for the rear left and right).

  Further, in the above-described embodiment, the case where the current control process is realized by the processor reading the program into the memory and executing the program is described. However, the present invention is not limited to this. Or may be realized by a combination of software and hardware.

  Further, in the above-described embodiment, the case where each power wheel 110 is configured to include the motor wheel 111, the inverter 112, and the power type battery 113 has been described. 110 includes a motor wheel 111 and an inverter 112, and the power type battery 113 may be provided outside the power wheel 110.

  In the above description, information such as a program, a table, and a file for realizing each function is stored in a memory, a hard disk, a storage device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD. Can be put on.

  Further, the above-described configuration may be appropriately changed, rearranged, combined, or omitted without departing from the scope of the present invention.

  According to the configuration described above, it is possible to suppress the fluctuation of the current of the second storage battery.

  DESCRIPTION OF SYMBOLS 1 ... Power supply system, 100 ... Electric vehicle, 110 ... Power wheel, 111 ... Motor wheel, 112 ... Inverter, 113 ... Power type battery, 120 ... Capacity type battery, 130 ... ECU, 140 ... switch, 150 ... ammeter.

Claims (14)

A plurality of first storage batteries;
A plurality of motors provided corresponding to the plurality of first storage batteries;
A plurality of inverters provided corresponding to the plurality of motors;
A second storage battery connected to the plurality of first storage batteries via a switch and having a larger capacity than the first storage battery;
A control unit that controls on and off of the switch so as to reduce a change in current related to the second storage battery;
A power supply system comprising: The second storage battery and the control unit are provided in an electric vehicle,
Power wheels each including one of the first storage battery, the motor, and the inverter are provided in front, rear, left, and right of the electric vehicle,
The switch is configured to include a right switch and a left switch,
The first storage batteries on the right are connected by a current line, and the second storage battery and the first storage battery on the right are connected via the switch on the right,
The first storage batteries on the left are connected by a current line, and the second storage battery and the first storage battery on the left are connected via the switch on the left.
The power supply system according to claim 1, wherein: The second storage battery and the control unit are provided in an electric vehicle,
Power wheels each including one of the first storage battery, the motor, and the inverter are provided in front, rear, left, and right of the electric vehicle,
The front, rear, left and right first storage batteries are connected by a current line, and the second storage battery and the front, rear, left and right first storage batteries are connected via the switch.
The power supply system according to claim 1, wherein: The second storage battery and the control unit are provided in an electric vehicle,
Power wheels each including one of the first storage battery, the motor, and the inverter are provided in front, rear, left, and right of the electric vehicle,
The switch is configured to include a right switch, a left switch, and a common switch,
The right first storage batteries are connected by a current line, and the second storage battery and the right first storage battery are connected via the right switch and the common switch,
The first storage batteries on the left are connected to each other via a current line, and the second storage battery and the first storage battery on the right are connected via the switch on the left and the common switch.
The power supply system according to claim 1, wherein: The control unit shifts a switching phase of an inverter carrier frequency of the inverters before and after by 180 degrees,
The power supply system according to any one of claims 2 to 4, wherein: The control unit shifts the motor phases of the left and right motors by 180 degrees when the rotation speeds of the left and right motors are aligned,
The power supply system according to any one of claims 2 to 4, wherein: The control unit turns off the switch when the switch is on, in a regenerative state, and the current of the second storage battery is a value corresponding to zero,
The power supply system according to claim 1, wherein: The control unit, when the switch is off, in a power running state, and the voltage difference between the voltage of the first storage battery and the voltage of the second storage battery is smaller than a predetermined threshold, Switch on,
The power supply system according to claim 7, wherein: The control unit includes:
When the information of the current from the monitoring unit that monitors the current related to the second storage battery is the code on the charging side, it is determined that the battery is in the regenerative state,
When the information of the current from the monitoring unit that monitors the current related to the second storage battery is the code on the discharging side, it is determined that the vehicle is in the powering state.
The power supply system according to claim 8, wherein: A right ammeter for measuring a current in the right switch and the second storage battery;
An ammeter on the left that measures current in the switch on the left and the second storage battery;
With
The control unit includes:
When the right switch is on and in a regenerative state, and the current of the right ammeter has a value corresponding to zero, the right switch is turned off;
When the left switch is on and in a regenerative state, and the current of the left ammeter has a value corresponding to zero, the left switch is turned off.
The power supply system according to claim 2, wherein: The control unit includes:
When the switch on the right side is off and in a powering state, and the voltage difference between the voltage of the first storage battery and the voltage of the second storage battery on the right side is smaller than a predetermined threshold value, Turn on the switch,
When the switch on the left side is off and in a power running state, and the voltage difference between the voltage of the first storage battery and the voltage of the second storage battery on the left side is smaller than a predetermined threshold value, Turn on the switch,
The power supply system according to claim 10, wherein: The control unit turns off the switch when the switch is on, in a regenerative state, and the current of the second storage battery is a value corresponding to zero,
The power supply system according to claim 3, wherein: The control unit is configured so that the switch is off and in a power running state, and a voltage difference between the front, rear, left, and right voltages of the first storage battery and the voltage of the second storage battery is smaller than a predetermined threshold. If the switch is turned on,
The power supply system according to claim 12, wherein: The switch is configured to include a first switch having a resistor and a second switch having a snubber capacitor,
The control unit turns on the first switch, and controls on and off of the second switch so as to reduce fluctuations in current related to the second storage battery.
The power supply system according to claim 1, wherein:

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