JP2008079436A - Power supply control unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply control unit capable of charging a capacitor and a battery during regeneration and of controlling the battery at a high pressure by boosting a battery voltage upon driving a motor. <P>SOLUTION: This power supply control unit 1 includes: an inverter 20 for supplying power from the chargeable and dischageable capacitor 30 and the chargeable and dischageable battery 50 to a motor/generator 10 and for supplying regenerative power from the motor/generator 10 to the capacitor 30 and the battery 50; a step-up/step-down converter 40 for stepping down the voltage of the regenerative power supplied from the inverter 20 and supplying it to the battery 50 and for stepping up the voltage of power discharged from the battery 50 and supplying it to the inverter 20; and a switching section 70 for switching from connection to disconnection and vice versa among the inverter 20, capacitor 30 and step-up/step-down converter 40. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power control device for a motor / generator that operates as an electric motor or a generator.

  Although an electric vehicle uses a vehicle drive motor as a drive source, it is known to use a secondary battery (battery) such as a lead storage battery or a nickel-cadmium battery as a power source for supplying power to the vehicle drive motor. However, such a secondary battery has a relatively short distance that can be traveled before discharging and a long charging time.

  On the other hand, there is a capacitor as a power storage means with a short charging time, and it has been proposed to use an electric double layer capacitor having a small capacity but a large capacity as a power source for an electric vehicle.

  Therefore, both a battery and a capacitor that can be rapidly charged are mounted as power storage means, and power is supplied from these power storage means to the vehicle drive motor based on the running state of the vehicle or the charged state of the capacitor. There has been considered an electric vehicle power supply control device that controls or controls regenerative charging from a vehicle drive motor to a power storage means (see, for example, Patent Document 1).

  FIG. 3 is a block diagram showing a schematic configuration of the electric vehicle power supply control device described in Patent Document 1. As shown in FIG. As shown in FIG. 3, the electric vehicle power supply control device includes a capacitor 101, a battery 104, a current detection circuit 105, an inverter 106, a one-way converter 108, a voltage detection circuit 109, a converter control unit 110, A switching relay 111 and a regenerative current wiring 112 are provided.

  Unidirectional converter 108 includes capacitor 180, transistor 182, diode 183, reactor 184, transistor 185, diode 186, capacitor 188, and current detection circuits 189 and 190. The capacitors 180 and 188 are for smoothing, and the current detection circuits 189 and 190 are for detecting the input current and output current of the unidirectional converter 18.

  The switching relay 111 includes a switching relay coil 1111, a switching relay contact 1112, and fixed contacts 111 </ b> A and 111 </ b> B.

  During regeneration, the regenerative current charges the capacitor 101 directly through the dedicated wiring 112. Since the one-way converter 108 is boosted or stepped down from the capacitor 101 side toward the battery 104 side, the capacitor charging voltage need not be lower than the battery voltage. When the regenerative current exceeds a predetermined value, the one-way converter 108 is operated, and the excess is sent to charge the battery 104. Then, the power loss in the capacitor 101 does not become large. When power is supplied from the capacitor 101, the voltage of the capacitor 101 is increased or decreased so that the output voltage of the unidirectional converter 108 is about the battery voltage.

JP-A-9-322314

  However, since the above-described electric vehicle power supply control device uses a unidirectional converter, the battery voltage is directly supplied to the inverter when the motor is driven. That is, since this converter does not boost the battery voltage, there is a circumstance that the inverter cannot be controlled at a high voltage using the power from the battery.

  The present invention has been made in view of the above circumstances, and is capable of charging a capacitor and a battery during regeneration, and boosting a battery voltage and controlling an inverter at a high voltage when driving a motor. An object of the present invention is to provide a power control device that can be used.

  A first aspect of the present invention is a power supply control device for a motor / generator that operates as an electric motor or a generator, and includes a chargeable / dischargeable capacitor, a chargeable / dischargeable battery, and at least one of the capacitor and the battery. An electric power is supplied to the motor / generator, and an regenerative power from the motor / generator is supplied to at least one of the capacitor and the battery, and a regenerative power supplied from the inverter is stepped down and supplied to the battery. And a step-up / down converter that boosts the electric power discharged from the battery and supplies the boosted power to the inverter.

  With this configuration, the buck-boost converter can perform boost / buck in both directions between the battery and the inverter, so that not only the capacitor but also the battery can be charged during regeneration and the motor is driven. Since the battery voltage can be boosted and supplied to the inverter, the inverter can be controlled at a high voltage.

  A second aspect of the present invention is the power supply control device according to the first aspect, wherein a capacitor voltage sensor that detects a voltage of the capacitor, a connection between the capacitor, the inverter, and the buck-boost converter, There is provided a power supply control device further including a capacitor connection switch that switches between opening and a control unit that controls the capacitor connection switch based on a voltage detected by the capacitor voltage sensor.

  With this configuration, since the control unit can switch the connection between the capacitor, the inverter, and the buck-boost converter based on the voltage of the capacitor, for example, depending on the state of charge of the capacitor, the power supply during motor driving or during regeneration As the charging destination, the selection / non-selection of the capacitor can be switched.

  Thirdly, the power supply control device according to the second aspect, wherein the control unit monitors the voltage of the capacitor detected by the capacitor voltage sensor during regeneration, and the capacitor is fully charged. Until then, a current control device is provided that controls the capacitor connection switch to a connected state and controls the capacitor connection switch to an open state when it is determined that the capacitor is fully charged.

  With this configuration, when the capacitor is fully charged, the regenerative power is charged to the battery via the step-up / down converter, so that the regenerative power can be used efficiently.

  Fourthly, the present invention provides the power supply control device according to the second or third aspect, wherein a current sensor that detects a regenerative current from the inverter, the battery, the inverter, and the capacitor connection switch A battery connection switch that switches between connection and release, and the control unit controls the battery connection switch to a connected state when the regenerative current detected by the current sensor is equal to or greater than a predetermined current value. A control device is provided.

  With this configuration, when the regenerative current is large, the battery is charged by connecting the inverter and the battery via a converter. For example, even if the instantaneous storage capacity of the capacitor is exceeded, Since the regenerative current can be charged to the battery, the regenerative power can be used efficiently.

  The fifth aspect of the present invention is the power supply control device according to the fourth aspect, wherein the control unit detects by the capacitor voltage sensor when a regenerative current detected by the current sensor is less than a predetermined current value. If it is determined that the capacitor is fully charged based on the voltage of the capacitor, the battery connection switch is controlled to be connected. If it is determined that the capacitor is not fully charged, the battery connection switch is opened. A power supply control device for controlling the power supply is provided.

  With this configuration, the connection between the inverter and the battery can be appropriately switched according to the capacitor voltage.

  Sixthly, the present invention provides the power supply control device according to the fourth or fifth aspect, wherein an inverter connection switch that switches connection or release between the inverter and the capacitor connection switch and the battery connection switch is provided. The power supply control device is further provided, wherein the control unit controls all of the capacitor connection switch, the battery connection switch, and the inverter connection switch to an open state when the motor / generator is not operated. It is.

  With this configuration, when the motor / generator is not operated, such as when the vehicle is stopped, discharge from the battery and the capacitor can be suppressed.

  Seventhly, the present invention provides the power supply control device according to any one of the second to sixth aspects, wherein the control unit is configured to output the inverter from the inverter according to a change in voltage detected by the capacitor voltage sensor. A power supply control device that controls electric power supplied to a motor / generator is provided.

  With this configuration, it is possible to suppress fluctuations in the output to the motor / generator due to changes in the voltage of the capacitor by controlling the inverter, such as performing high frequency control according to the capacitor voltage.

  According to the present invention, it is possible to provide a power supply control device capable of charging a capacitor and a battery during regeneration and boosting a battery voltage and controlling an inverter at a high voltage when driving a motor. it can.

  FIG. 1 is a diagram showing a schematic configuration of a power supply control device according to an embodiment of the present invention. The power supply control device 1 of this embodiment performs power supply control of a motor / generator (hereinafter referred to as M / G) 10 that operates as an electric motor or a generator.

  In the present embodiment, a case where the M / G 10 is used as power for an electric vehicle will be described. At this time, the M / G 10 operates as an electric motor with the electric power supplied from the power supply control device 1 to drive the vehicle. Further, it operates as a generator by the driving force from the wheels and the engine during deceleration of the vehicle, and supplies power to the power supply control device 1.

  In addition, the power supply control apparatus 1 of this embodiment is applicable not only to an electric vehicle but to a system having M / G, storing regenerative energy and using it as motor drive energy. Examples of using such a system include an electric motorcycle, a hybrid vehicle, a self-supporting train, an elevator, a ship, an electric wheelchair, and an electric carriage for cargo transportation.

  As shown in FIG. 1, the power supply control device 1 includes an inverter 20, a capacitor 30, a buck-boost converter 40, a battery 50, a capacitor voltage sensor 61, a battery voltage sensor 62, a current sensor 63, and a switching unit. 70 and a control unit 80.

  The inverter 20 includes a three-phase bridge having MOSFETs 21a, 21b, 21c, 21d, 21e, and 21f, and feedback diodes 22a, 22b, 22c, 22d connected in parallel to the MOSFETs 21a, 21b, 21c, 21d, 21e, and 21f, respectively. 22e and 22f, and an inverter control circuit 23 that controls the gate voltages of the MOSFETs 21 to 21f and switches them on and off based on control from the control unit 80. The inverter 20 supplies power from at least one of the capacitor 30 and the battery 50 to the M / G 10 and supplies regenerative power from the M / G 10 to at least one of the capacitor 30 and the battery 50.

  The capacitor 30 is connected in parallel to the inverter 20, stores the electric power supplied from the M / G 10 via the inverter 20, and supplies the electric power when driving the M / G 10 via the inverter 20. As the capacitor 40, for example, a large capacity capacitor such as an electric double layer capacitor is used.

  The step-up / down converter 40 is connected in parallel to the inverter 20 and the capacitor 30, MOSFETs 41 a and 41 b, feedback diodes 42 a and 42 b connected in parallel to the MOSFETs 41 a and 41 b, a reactor 43, a capacitor 44, and a control unit 80. And a step-up / step-down control circuit 45 that controls the gate voltages of the MOSFETs 41a and 41b and switches on and off based on the control from the above.

  The MOSFET 41a functions as a step-down transistor that steps down the output from the switching unit 70, and the MOSFET 41b functions as a step-up transistor that steps up the output from the battery 50. Reactor 43 accumulates or discharges the electric power output from switching unit 70 or output from battery 50. The capacitor 44 functions as a smoothing capacitor that smoothes the output during step-down.

  Thus, the step-up / step-down converter 40 steps down the regenerative power supplied from the inverter 20 and supplies it to the battery 50, and boosts the electric power discharged from the battery 50 and supplies it to the inverter 40 in both directions. Functions as a converter.

  The battery 50 is a secondary battery that is connected in parallel with the step-up / down converter 40 and is chargeable / dischargeable. For the battery 50, for example, a secondary battery such as a lead storage battery or a nickel / cadmium battery is used.

  Capacitor voltage sensor 61 is connected in parallel with capacitor 30, detects the voltage of capacitor 30, and outputs the detected value to control unit 80.

  The battery voltage sensor 62 is connected in parallel with the battery 50, detects the voltage of the battery 50, and outputs the detected value to the control unit 80.

  The current sensor 63 is connected in series to the inverter 20 and detects a current flowing between the inverter 20, the capacitor 30, and the buck-boost converter 40, such as a regenerative current flowing from the inverter 20 toward the capacitor 30 and the battery 50. The detected value is output to the control unit 80.

  The switching unit 70 includes an inverter connection switch 71, a converter connection switch 72, and a capacitor connection switch 73, and switches connection / release between the inverter 20, the capacitor 30, and the buck-boost converter 40. Each switch 71, 72, 73 is switched based on control from the control unit 80.

  The inverter connection switch 71 is connected in series with the inverter 20, and switches connection or release between the inverter 20 and the converter connection switch 72 and the capacitor connection switch 73. That is, the inverter 20 is switched between connection and release with respect to the capacitor 30 or the buck-boost converter 40.

  The converter connection switch 72 is connected in series with the step-up / step-down converter 40 and switches connection / release between the step-up / step-down converter 40 and the inverter connection switch 71 and the capacitor connection switch 73. That is, the step-up / down converter 40 is switched between connection and release with respect to the inverter 20 or the capacitor 30.

  The capacitor connection switch 73 is connected in series with the capacitor 30 and switches connection or release between the capacitor 30 and the inverter connection switch 71 and the converter connection switch 72. In other words, the capacitor 30 is switched between connection and release with respect to the inverter 20 or the step-up / down converter 40. Since the control unit can switch the connection between the capacitor and the inverter and the buck-boost converter based on the voltage of the capacitor, for example, depending on the charge state of the capacitor, the power supply source at the time of driving the motor, or at the time of regeneration Capacitor selection / non-selection can be switched as a charging destination.

  The control unit 80 performs switching control of the switches 71, 72, and 73 of the switching unit 70 based on the detection signals output from the capacitor voltage sensor 61, the battery voltage sensor 62, and the current sensor 63, and the inverter control circuit 23. And the step-up / down control circuit 55 is controlled.

  Next, the operation of the power supply control device configured as described above will be described. FIG. 2 is a diagram for explaining the operation of the power supply control apparatus according to the embodiment of the present invention.

  First, a description will be given of EV traveling when the M / G 10 is driven as an electric motor and used as vehicle power (see items 1 to 4 in FIG. 2).

  During EV travel, the control unit 80 controls the switching unit 70 based on the voltage of the capacitor 30 and the battery 50 detected by the capacitor voltage sensor 61 and the battery voltage sensor 62. The controller 80 compares the detection value output from the capacitor voltage sensor 61 with the threshold value for determining the capacitor voltage during EV traveling during EV traveling, and if the detected value is equal to or greater than the threshold value, the voltage of the capacitor 30 Is lower than the threshold, it is determined that the voltage of the capacitor 30 is lower. Similarly, the detection value output from the battery voltage sensor 62 is compared with a threshold value for determining battery voltage during EV travel. If the detection value is equal to or greater than the threshold value, the voltage of the battery 50 is high, and if the detection value is less than the threshold value, the battery It is determined that the voltage of 50 is low.

  As shown in item No. 1 and item No. 2 in FIG. 2, when the voltage of the capacitor 30 is high, the control unit 80 connects the inverter connection switch 71 and the capacitor connection switch 73 (energized state: ON), converter The connection switch 72 is controlled to an open state (insulation state: OFF). Therefore, the energy stored in the capacitor 30 is supplied to the M / G 10 via the inverter 20, and EV traveling is realized.

  Note that, when EV traveling is performed with the power from the capacitor 30, the voltage of the capacitor 30 varies due to the discharge of the capacitor 30, so the power supplied to the inverter 20 varies. Therefore, the control unit 80 controls the inverter control circuit 23 according to the change in the voltage of the capacitor 30 detected by the capacitor voltage sensor 61, and controls the power supplied from the capacitor 30 to the M / G 10. Thereby, by controlling the inverter 20 such as high-frequency control according to the voltage of the capacitor 30, fluctuations in the output to the M / G 10 due to the voltage change of the capacitor 30 can be suppressed.

  2, when the voltage of the capacitor 30 is low and the voltage of the battery 50 is high, the control unit 80 controls the inverter connection switch 71, the converter connection switch 72, and the capacitor connection switch 73. Control everything to ON. Further, the control unit 80 controls the step-up / step-down control circuit 45 so that the step-up / step-down converter 40 boosts the output from the battery 50 and supplies it to the inverter 20. Thereby, EV traveling by the electric power from the battery 50 is realized. In this way, the output of the battery 50 can be boosted and supplied to the inverter 20, so that the inverter 20 can be controlled at a high voltage.

  When the capacitor switch 73 is controlled to be in the ON state, the power from the battery 50 is charged into the capacitor 1, and the capacitor 1 causes the influence of surge due to the motor load fluctuation of the M / G 10, and the step-up / down converter 40. The influence of ripples and the like due to the voltage boosting is suppressed. That is, the capacitor 1 functions as a smoothing capacitor that smoothes the output of the step-up / down converter 40 during boosting.

  As shown in item number 4 of FIG. 2, when both the voltage of the capacitor 30 and the voltage of the battery 50 are low, the EV travel is performed with the power generation of the M / G 10. At this time, the control unit 80 controls the inverter connection switch 71, the converter connection switch 72, and the capacitor connection switch 73 to the ON state. The electric power generated by the M / G 10 charges the battery 50 with electric power that is stepped down to the stored voltage of the battery 50 via the buck-boost converter 40 while being stored in the capacitor 30 via the inverter 20. . On the other hand, EV traveling is realized by driving the M / G 10 with the electric power generated by the generator under the control of the inverter 20. Here, an internal combustion engine such as an engine is used as power generation energy by the generator.

  Next, a description will be given of regeneration when the M / G 10 operates as a generator to regenerate power to the capacitor 30 and the battery 50 (see items 5 to 12 in FIG. 2).

  During regeneration, the amount of current regenerated through the inverter 20 from the M / G 10 varies greatly depending on the braking condition of the vehicle. Therefore, at the time of regeneration, the control unit 80 switches the switching unit 70 based on the regenerative current detected by the current sensor 63 in addition to the voltages of the capacitor 30 and the battery 50 detected by the capacitor voltage sensor 61 and the battery voltage sensor 62. To control. At this time, the regenerative current and voltage are appropriately controlled by the inverter control circuit 23 based on the control of the control unit 80.

  The controller 80 monitors the detection value output from the capacitor voltage sensor 61 during regeneration. When the capacitor 30 is fully charged, that is, when the voltage of the capacitor 30 is saturated, the voltage of the capacitor 30 is high. It is determined that the voltage of the capacitor 30 is low until the capacitor 30 is fully charged, that is, until the voltage of the capacitor 30 is saturated. The high / low level may be determined based on whether the voltage of the capacitor 30 is equal to or higher than a predetermined threshold value, instead of being determined based on whether or not the battery is fully charged.

  Further, the control unit 80 compares the detection value output from the battery voltage sensor 62 with a threshold value for determining the battery voltage during regeneration, and if the detection value is equal to or higher than the threshold value, the voltage of the battery 50 is higher or lower than the threshold value. If there is, it is determined that the voltage of the battery 50 is low. In addition, the threshold value for battery voltage determination at the time of regeneration is about 80% of the voltage at the time of full charge of the capacitor 30, for example.

  2, when the current amount of the regenerative current is small (the regenerative amount is small) and the voltage of the capacitor 30 is high, the control unit 80 includes the inverter connection switch 71 and the converter. The connection switch 72 is controlled to be in the ON state and the capacitor connection switch 73 is controlled to be in the OFF state. Further, the control unit 80 controls the step-up / step-down control circuit 45, so that the step-up / step-down converter 40 steps down the output from the inverter 20 and supplies it to the battery 50.

  As described above, when the control unit 80 determines that the voltage of the capacitor 30 is high, that is, the capacitor 30 is fully charged, the regenerative power is supplied to the capacitor 30 by controlling the capacitor connection switch 73 to the OFF state. Not supplied. In addition, since converter connection switch 72 is controlled to be in the OFF state, regenerative power is supplied to battery 50 and battery 50 can be charged. Therefore, when the capacitor voltage is high, the battery 50 can be appropriately selected as a charging destination.

  2, when the regenerative amount is small and the voltage of the capacitor 30 is low, the control unit 80 turns on the inverter connection switch 71 and the capacitor connection switch 73 and connects the converter. The switch 72 is controlled to be in an OFF state.

  As described above, the control unit 80 supplies the regenerative power to the capacitor 30 by controlling the capacitor connection switch 73 to the ON state until the voltage of the capacitor 30 is low, that is, until the capacitor 30 is fully charged. be able to. Moreover, since the converter connection switch 72 is controlled to be in the OFF state, regenerative power is not supplied to the battery. Therefore, when the capacitor voltage is low, the capacitor 30 can be appropriately selected as a charging destination.

  As shown in item numbers 9 and 10 in FIG. 2, when the regenerative amount is large and the voltage of the capacitor 30 is high, as in the case of the item numbers 5 and 6, the control unit 80 is an inverter. The connection switch 71 and the converter connection switch 72 are controlled to be in an ON state, and the capacitor connection switch 73 is controlled to be in an OFF state. Further, the control unit 80 controls the step-up / step-down control circuit 45, so that the step-up / step-down converter 40 steps down the output from the inverter 20 and supplies it to the battery 50.

  Thus, when the control unit 80 determines that the capacitor 30 is fully charged, the regenerative power is not supplied to the capacitor 30 but is supplied to the battery 50. Therefore, when the capacitor voltage is high, the battery 50 can be appropriately selected as a charging destination.

  2, when the regenerative amount is large and the voltage of the capacitor 30 is low, the control unit 80 controls the inverter connection switch 71, the converter connection switch 72, and the capacitor connection switch 73. Control everything to ON. In addition, the control unit 80 controls the step-up / step-down control circuit 45 so that the step-up / step-down converter 40 steps down the output from the inverter 20 and supplies it to the battery 50.

  In this way, the control unit 80 controls the capacitor connection switch 73 to be in the ON state until the voltage of the capacitor 30 is low, that is, until the capacitor 30 is fully charged, so that the regenerative power is charged to the capacitor 30. be able to. Furthermore, the control unit 80 controls the converter connection switch 72 to the ON state and controls the step-up / down converter 40, whereby the regenerative amount is large and the current output from the inverter 20 exceeds the instantaneous storage capacity of the capacitor 30. Even in such a case, the surplus current can be charged to the battery 50. In this way, regenerative power can be used efficiently.

  Next, a case where the M / G 10 is not operated will be described (see item number 13 in FIG. 2). Further, since neither EV traveling nor regeneration is performed while the vehicle is stopped, the control unit 80 controls all of the inverter connection switch 71, the converter connection switch 72, and the capacitor connection switch 73 to the ON state. In this way, discharge from the battery and capacitor can be suppressed when the M / G 10 is not operated, such as when the vehicle is stopped.

  According to such an embodiment of the present invention, since the buck-boost converter can perform the buck-boost in both directions between the battery and the inverter, not only the capacitor but also the battery can be charged during regeneration. In addition, since the battery voltage can be boosted and supplied to the inverter when the motor is driven, the inverter can be controlled at a high voltage.

  In the above embodiment, the case where the switching unit 70 includes three switches has been described. However, the switching unit 70 includes only the converter connection switch 72 and the capacitor connection switch 73 according to the functions realized by the power supply control device 1. Alternatively, the switching unit 70 may include only the capacitor connection switch 73.

  In the above embodiment, the M / G 10 has been described as an example of a generator that supplies power to the inverter. However, the generator may be a variety of generators such as a fuel cell, a solar cell, or a generator using hydrogen. It may be used.

  The power supply control device of the present invention can charge the capacitor and the battery during regeneration, and has the effect of boosting the battery voltage and controlling the inverter at a high voltage when driving the motor. / Useful for systems that have a generator and store regenerative energy and use it as motor drive energy.

The figure which shows schematic structure of the power supply control apparatus which concerns on embodiment of this invention. The figure explaining operation | movement of the power supply control apparatus which concerns on embodiment of this invention. The block diagram which shows schematic structure of the electric vehicle power supply control apparatus described in patent document 1

Explanation of symbols

1 Power supply control device 10 Motor / generator (M / G)
20 Inverter 21a, 21b, 21c, 21d, 21e, 21f MOSFET
22a, 22b, 22c, 22d, 22e, 22f Feedback diode 23 Inverter control circuit 30 Capacitor 40 Buck-boost converter 41a, 41b MOSFET
42a, 42b Feedback diode 43 Reactor 44 Capacitor 50 Battery 61 Capacitor voltage sensor 62 Battery voltage sensor 63 Current sensor 70 Switching unit 71 Inverter connection switch 72 Converter connection switch 73 Capacitor connection switch 80 Control unit 101 Capacitor 104 Battery 105 Current detection circuit 106 Inverter DESCRIPTION OF SYMBOLS 107 Vehicle drive motor 108 Unidirectional converter 109 Voltage detection circuit 110 Converter control part 111 Switching relay 1111 Switching relay coil 1112 Switching relay contact 111A, 111B Fixed contact 112 Regenerative current exclusive wiring 180 Capacitor 182 Transistor 183 Diode 184 Reactor 185 Transistor 186, 188 Capacitors 189, 190 Current detection circuit

Claims (7)

A power supply control device for a motor / generator that operates as an electric motor or a generator,
A chargeable / dischargeable capacitor;
A chargeable / dischargeable battery;
An inverter that supplies electric power from at least one of the capacitor and the battery to the motor / generator and supplies regenerative power from the motor / generator to at least one of the capacitor and the battery;
A step-up / down converter that steps down the regenerative power supplied from the inverter and supplies it to the battery, and steps up the power discharged from the battery and supplies the boosted power to the inverter. The power supply control device according to claim 1,
A capacitor voltage sensor for detecting the voltage of the capacitor;
A capacitor connection switch that switches connection or release between the capacitor and the inverter and the buck-boost converter;
And a control unit that controls the capacitor connection switch based on a voltage detected by the capacitor voltage sensor. The power supply control device according to claim 2,
The controller monitors the voltage of the capacitor detected by the capacitor voltage sensor during regeneration, controls the capacitor connection switch to a connected state until the capacitor is fully charged, and the capacitor is fully charged. A current control device for controlling the capacitor connection switch to an open state when it is determined that the capacitor connection switch is present. The power supply control device according to claim 2 or 3,
A current sensor for detecting a regenerative current from the inverter;
A battery connection switch that switches connection or release between the battery and the inverter and the capacitor connection switch;
When the regenerative current detected by the current sensor is equal to or greater than a predetermined current value, the control unit controls the battery connection switch to be in a connected state. The power supply control device according to claim 4,
The control unit, when the regenerative current detected by the current sensor is less than a predetermined current value,
If it is determined that the capacitor is fully charged based on the voltage of the capacitor detected by the capacitor voltage sensor, the battery connection switch is controlled to be connected, and if it is determined that the capacitor is not fully charged, A power supply control device that controls the battery connection switch to an open state. The power supply control device according to claim 4 or 5,
An inverter connection switch for switching connection or release between the inverter and the capacitor connection switch and the battery connection switch;
The control unit is a power supply control device that controls all of the capacitor connection switch, the battery connection switch, and the inverter connection switch to an open state when the motor / generator is not operated. The power supply control device according to any one of claims 2 to 6,
The control unit is a power supply control device that controls electric power supplied from the inverter to the motor / generator in accordance with a change in voltage detected by the capacitor voltage sensor.

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