JP2012115060A - Power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply unit for producing an AC voltage with an optional magnitude from a power supply such as a storage cell, capable of driving a power conversion section including starting and storage cell charging.SOLUTION: A power supply unit 100 includes: a power conversion section 8 which is connected with a storage cell 5 on the input side, is selectively connected with a load 7 or a commercial power supply 6 on the output side and can be power-converted bidirectionally; a snubber circuit 9 which includes diodes 91a-91f, diodes 92a-92d and a capacitor 93, rectifies output AC voltage with the diodes 91a-91f and the diodes 92a-92d to charge the capacitor 93, and absorbs a surge voltage generated while a power conversion section 8 is operating; a main control power supply 31; and a diode 33 which selects a DC voltage based on the storage cell 5 or a DC charging voltage charged into the capacitor 93, whichever is higher and supplies the voltage to the main control power supply 31.

Description

  The present invention relates to a power supply device that can generate an AC voltage of an arbitrary magnitude from a power source such as a storage battery and that can also charge the storage battery, and more particularly, to a power supply device that includes a power conversion unit having a plurality of bidirectional switching elements.

  Conventionally, as a power supply device used in a power supply device that generates an AC voltage of an arbitrary size from a power supply such as a storage battery, a storage battery, a plurality of bidirectional switching elements connected in a matrix, and an inductor (reactor) A power conversion device (power supply device) provided is known. In this power converter, the DC voltage of the storage battery is converted into a single-phase AC voltage and output by switching control of the step-down operation mode or step-up operation mode using a plurality of bidirectional switching elements and inductors, and PWM control. It is configured. Moreover, in this power converter, when charging a storage battery, a commercial power source is connected to the output side, and a single-phase AC voltage of the commercial power source is converted into a DC voltage and supplied to the storage battery.

  On the other hand, a matrix converter (power supply device) that uses a DC voltage of a snubber circuit having a function of absorbing a transient voltage as a control power supply is known (for example, see Patent Document 1).

  Patent Document 1 discloses a main circuit composed of a plurality of bidirectional switching elements, a snubber circuit that suppresses an overvoltage when the gate of the bidirectional switching elements is cut off by a rectifier mechanism and a common capacitor configuration, and an AC power supply. AC precharging circuit that precharges the capacitor with a resistor and a switch provided between the power source and the snubber circuit, a gate drive circuit and a control circuit for driving the bidirectional switching element of the main circuit, a gate drive circuit from the DC power source, and A matrix converter including a switching regulator that obtains a power supply for a control circuit is disclosed. The switching regulator in the matrix converter according to Patent Document 1 supplies AC power to the power source of the gate drive circuit and the power source of the control circuit using a common capacitor for each phase of the snubber circuit as a DC power source. Thereby, it is not necessary to provide a separate control power supply, so that the configuration of the matrix converter can be simplified. Note that this matrix converter is configured such that three-phase alternating current is input from an alternating current power source. In addition, this matrix converter is configured to output a three-phase alternating current to the motor.

  Here, it is conceivable to use the snubber circuit of Patent Document 1 as a power source for driving a bidirectional switching element of a power supply device that generates an AC voltage of an arbitrary magnitude from a power source such as the storage battery. Thus, when the snubber circuit of Patent Document 1 is applied to a power supply device that generates an AC voltage of an arbitrary size from a power supply such as a storage battery, a capacitor included in the snubber circuit is a commercial power supply or bidirectional switching. Since the capacitor is charged by a transient surge voltage generated when the gate of the element is cut off, it is considered that this capacitor can be used as a power source for driving the bidirectional switching element. In other words, it is included in the snubber circuit during normal operation when the commercial power supply is connected to the output side of the power supply device for charging the storage battery, and when the surge voltage generated when the gate of the bidirectional switching element is cut off, and during the charging operation of the storage battery. It is considered that the capacitor can be used as a power source for driving the bidirectional switching element. Thereby, unlike the case where a power supply for driving the bidirectional switching element is separately provided, the power supply apparatus can be reduced in size.

JP 2008-295219 A

  However, in a configuration in which the snubber circuit of Patent Document 1 is applied to a power supply device that generates an AC voltage of an arbitrary size from a power supply such as the storage battery in order to reduce the size of the power supply device, charging of the storage battery is performed during normal operation. When the power supply device is started or stopped at other times, the voltage of the capacitor of the snubber circuit becomes smaller than that during normal operation and during charging. For this reason, at the time of starting the power supply device (power conversion unit), it is considered that there is a problem that the voltage of the power source for driving the bidirectional switching element is insufficient and the bidirectional switching element cannot be driven. It is not necessary to drive the bidirectional switching element at the time of stop, so there is no problem even if the bidirectional switching element cannot be driven. In order to solve the above problems, a storage battery may be used as a power source for driving the bidirectional switching element. With such a configuration, the bidirectional switching element is driven when the storage battery is charged. This is considered to cause a problem that the power supply is lost.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a power supply device that generates an AC voltage of an arbitrary size from a power source such as a storage battery. An object of the present invention is to provide a power supply device that can drive a power conversion unit even when a storage battery is charged.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a power supply device according to one aspect of the present invention has a storage battery as a DC power source connected to an input side, a load or a commercial power source selected and connected to an output side, and bidirectional power conversion Power converter, a rectifier element and a capacitor, a snubber circuit that rectifies the output AC voltage by at least the rectifier element to charge the capacitor, and absorbs a surge voltage generated during operation of the power converter, and a power converter A selection circuit that selects the higher voltage of the main control power supply that generates the power supply voltage for driving the battery, the DC voltage based on the storage battery, and the DC charging voltage charged in the capacitor of the snubber circuit and supplies the selected voltage to the main control power supply And.

  In the power supply device according to this aspect, as described above, a selection circuit that selects the higher voltage of the DC voltage based on the storage battery and the DC charging voltage charged in the capacitor of the snubber circuit and supplies the selected voltage to the control power supply. Since the voltage of the capacitor of the snubber circuit is reduced by the provision, the DC voltage based on the storage battery is selected by the selection circuit and supplied to the control power supply at the time of starting and stopping the power conversion unit in the discharge of the storage battery. The power conversion unit can be driven and controlled even when the unit is activated. In addition, since the output AC voltage is rectified by the rectifier and the capacitor of the snubber circuit is charged, the capacitor of the snubber circuit is charged by the AC voltage of the AC power supply when charging the storage battery by connecting the AC power supply to the output side. Since the voltage of the capacitor is selected by the selection circuit and supplied to the control power supply, the power conversion unit can be driven and controlled.

  In the power supply device according to the above aspect, the power conversion unit includes a plurality of bidirectional switching elements arranged in a matrix. If comprised in this way, even if it is a power supply device which has the matrix converter which converts the voltage of a storage battery into an alternating voltage in a power converter, a power converter can be reliably drive-controlled through charging / discharging of a storage battery.

In the power supply device according to the above aspect, the reactor further includes a reactor provided between the positive electrode of the storage battery and the power converter, and a capacitor connected in parallel with the power converter on the output side of the power converter,
The power conversion unit includes a plurality of bidirectional switching elements arranged in a matrix, and is connected to one end of the reactor, the other end of the reactor, and the negative electrode of the storage battery. If comprised in this way, even if the power converter which has the matrix converter which raises or lowers the voltage of a storage battery with a reactor and supplies it to a load in the power converter, the power converter can be reliably driven and controlled through charging and discharging of the storage battery. it can.

  In the power supply device according to the above aspect, the power supply device further includes a DC voltage conversion unit that converts the first DC voltage from the storage battery into a second DC voltage, and the selection circuit includes the second DC voltage converted by the DC voltage conversion unit, A voltage higher than the DC charging voltage of the snubber circuit capacitor is selected and supplied to the main control power supply. If comprised in this way, even when the voltage of a storage battery is not a voltage suitable for drive-controlling a power converter, the voltage of a storage battery is converted into the voltage suitable for driving-controlling a power converter by a DC voltage converter Therefore, it is possible to reliably drive and control the power conversion unit.

  In this case, the DC voltage converter is configured to boost the first DC voltage to the second DC voltage. If comprised in this way, even when the voltage of a storage battery is not a voltage high enough to control a power converter, since the voltage of a storage battery is boosted by a DC voltage converter, drive control of the power converter is ensured. can do.

  In the power supply device that boosts the first DC voltage to the second DC voltage by the DC voltage conversion unit, the second DC voltage boosted by the DC voltage conversion unit is based on the DC charging voltage of the capacitor of the snubber circuit during the snubber circuit operation. Is set to be low. With this configuration, during charging of the storage battery in which the snubber circuit operates and during normal operation, the DC voltage charged in the snubber circuit capacitor is selected by the selection circuit and supplied to the control power supply. The capacitor can be used as a power source for driving the power converter. The normal operation means that the DC voltage from the storage battery is converted to an AC voltage via a plurality of bidirectional switching elements and supplied to the load. In normal operation, the bidirectional switching is performed. The capacitor of the snubber circuit is always charged by a transient surge voltage generated when the element gate is cut off. Further, when charging the storage battery, the snubber circuit capacitor is always charged by the voltage of the commercial power supply or the voltage of the commercial power supply plus the surge voltage generated when the gate of the bidirectional switching element is shut off.

  In the power supply device that boosts the first DC voltage to the second DC voltage by the DC voltage converter, the selection circuit selects the second DC voltage boosted by the DC voltage converter at least when the power converter is started and stopped And is supplied to the main control power supply. With this configuration, the voltage of the capacitor of the snubber circuit is low when the power conversion unit is started and stopped. Therefore, the second DC voltage boosted by the DC voltage conversion unit when the power conversion unit is started and stopped is reduced. By supplying, it is possible to reliably drive and control the power conversion unit when the power conversion unit is activated. Furthermore, since the power conversion unit only starts for a short time and does not need to drive the bidirectional switching element when the power conversion unit is stopped, the capacity of the DC voltage conversion unit that generates the second DC voltage is reduced. Can be downsized.

  In the power supply device according to the above aspect, the selection circuit is configured by a diode. If comprised in this way, the higher voltage of the direct-current voltage based on a storage battery and the direct-current charging voltage charged in the capacitor | condenser of the snubber circuit can be supplied to a control power supply by simple structure.

  The power supply device according to the above aspect further includes a selection switch that selectively connects a load or a commercial power supply to the output of the power conversion unit, and the selection switch is commercialized to the output of the power conversion unit when the storage battery is charged. By switching so that the power supply is connected, the capacitor of the snubber circuit is charged using the commercial power supply, and the power conversion unit converts the AC voltage of the commercial power supply to a DC voltage to charge the storage battery, and the bidirectional power conversion unit The snubber circuit is configured to absorb a surge voltage generated when the gate of the switching element is cut off. If comprised in this way, when the charge amount of a storage battery becomes empty, a commercial power source will be connected to the output of a power converter part by a selection switch, and the capacitor | condenser of a snubber circuit will be charged with a commercial power source. Therefore, when the storage battery is charged using the commercial power source by the power conversion unit, the power conversion unit can be driven and controlled using the capacitor of the snubber circuit as a power source.

1 is a circuit diagram showing an overall configuration of a power supply device according to a first embodiment of the present invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage fall mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage fall mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage rise mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage rise mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage fall mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage fall mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage rise mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage rise mode at the time of discharge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage fall mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage fall mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage rise mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the positive pressure | voltage rise mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage reduction mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage reduction mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage rise mode at the time of charge by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the negative pressure | voltage rise mode at the time of charge by 1st Embodiment of this invention. It is a circuit diagram for demonstrating the operation | movement at the time of normal operation | movement of the power supply device by 1st Embodiment of this invention. It is a circuit diagram for demonstrating the operation | movement at the time of starting and stopping of the power supply device by 1st Embodiment of this invention. It is a circuit diagram for demonstrating the operation | movement at the time of charge of the power supply device by 1st Embodiment of this invention. It is a circuit diagram which shows the whole structure of the power supply device by 2nd Embodiment of this invention. It is a circuit diagram which shows the whole structure of the power supply device by 3rd Embodiment of this invention.

  Hereinafter, the present embodiment will be described with reference to the drawings.

(First embodiment)
First, a schematic configuration of the power supply device 100 according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 1, the power supply device 100 according to the first embodiment includes a power circuit unit 1, a control circuit unit 2, a control power supply unit 3, a switch unit 4, and a storage battery 5. Moreover, the switch part 4 is comprised so that the commercial power supply 6 and the load 7 may be selected and connected.

  The power circuit unit 1 includes a power conversion unit 8, a snubber circuit 9, a reactor 10, and a capacitor 82. The power converter 8 includes bidirectional switching elements 81a to 81f. The snubber circuit 9 includes a rectifier circuit 91 including diodes 91a to 91f, a rectifier circuit 92 including diodes 92a to 92d, and a capacitor 93. Contains.

  The control power supply unit 3 includes a main control power supply 31, a DC / DC converter 32, and a selection circuit 33 including a diode 33a. The DC / DC converter 32 is an example of the “DC voltage converter” in the present invention. The control circuit unit 2 receives power from the main control power supply 31 and supplies gate signals to these elements in order to drive the bidirectional switching elements 81a to 81f of the power converter 8.

  Normally, the load 7 is selected by the changeover switch unit 4 according to the user's selection, and the power supply apparatus 100 boosts or steps down the DC voltage supplied from the storage battery 5 by the power conversion unit 8 and supplies the DC voltage to the load 7. At this time, the storage battery 5 is discharging. The power supply device 100 can also be operated to charge the storage battery 5. At this time, the commercial power supply 6 is selected by the changeover switch unit 4 according to the user's selection, and the power supply device 100 is supplied with the AC voltage supplied from the commercial power supply 6. Is stepped up or stepped down and supplied to the storage battery 5. That is, in operation of the power supply apparatus 100, the storage battery 5 is discharged or charged. In discharging and charging of these storage batteries 5, for example, a start signal (not shown) is input to the control circuit 2, and when the start signal is turned on, a gate signal is sent from the control circuit 2 to the bidirectional switching element included in the power conversion unit 8. By being supplied, the power supply apparatus 100 operates. When the start signal is turned off, the supply of the gate signal from the control circuit 2 is stopped, and the power supply apparatus 100 is stopped. In both cases of charging and discharging of the storage battery 5, when the power supply device 100 is operated, a surge voltage generated when the gates of bidirectional switching elements 81 a to 81 f, which will be described later, included in the power conversion unit 8 are shut off is charged in the capacitor 93 of the snubber circuit 9. Is done. The time when the power supply device 100 is in operation and the capacitor 93 is constantly charged with a surge voltage generated when the gate is shut off is referred to as a normal operation time.

  On the other hand, when the power supply device 100 is stopped when the bidirectional switching elements 81 a to 81 f are not operated, the capacitor 93 is charged by the storage battery 5 and the changeover switch 4 when the load 7 is selected by the changeover switch unit 4. Therefore, when the commercial power source 6 is selected, the capacitor 93 is charged by the commercial power source 6 and is not charged by the surge voltage when the gates of the bidirectional switching elements 81a to 81f are cut off. Immediately after the power supply device 100 is started up, there is still little charge charge accumulation due to the surge voltage of the capacitor 93 of the snubber circuit 9. Thus, immediately after starting the power supply apparatus 100 and when it is stopped, the voltage charged in the capacitor 93 is lower than that during operation of the power supply apparatus 100.

  The charging voltage of the capacitor 93 and the output voltage of the DC / DC converter 32 are input to the selection circuit 32, and the higher voltage of both is selected and output to the main control power supply 31. For this reason, the charging voltage of the capacitor 93 is selected during normal operation during discharging of the storage battery 5. In the discharge of the storage battery 5, the voltage obtained by boosting the voltage of the storage battery 5 by the DC / DC converter 32 immediately after startup when the voltage of the capacitor 93 has not yet reached the output voltage of the DC / DC converter 32 and when it is stopped. Is selected and output to the main control power supply 31. Further, in charging the storage battery 5, since the storage battery 5 is empty, the charging voltage of the capacitor 93 is always selected. Therefore, the control circuit unit 2 is supplied with a high enough voltage from the main control power supply 31 to always drive the bidirectional switching elements 81 a to 81 f of the power conversion unit 8 through charging and discharging of the storage battery 5. It should be noted that the time immediately after startup and when the voltage of the capacitor 93 has not yet reached the output voltage of the DC / DC converter 32 is referred to as startup.

  Next, a detailed configuration of the power supply device 100 according to the first embodiment of the present invention will be described with reference to FIG.

  A storage battery 5 as a DC power source is connected to the input side (primary side) of the power circuit unit 1. Storage battery 5 has a DC voltage lower than the voltage of commercial power supply 6, for example, a voltage of 40V. The switch unit 4 is provided on the output side (secondary side) of the power circuit unit 1. The switch unit 4 is configured to be connectable to either the commercial power source 6 or the load 7. Commercial power supply 6 is an AC power supply having a voltage of 100 V, for example.

  Each of the bidirectional switching elements 81a to 81f of the power conversion unit 8 is configured by connecting two unidirectional switches 85 in which an IGBT 83 (Insulated Gate Bipolar Transistor) and a diode 84 are connected in series to each other in antiparallel. In addition, the six bidirectional switching elements 81 a to 81 f form a matrix (lattice) connection that connects each phase on the input side and each phase on the output side of the power converter 8.

  The input side (storage battery 5 side) of the bidirectional switching element 81 a is connected to one end 10 a of the reactor 10. The other end 10 b of the reactor 10 is connected to the positive electrode of the storage battery 5 via a terminal R. In addition, the input side of the bidirectional switching element 81 b is connected to the other end 10 b of the reactor 10. The input side of the bidirectional switching element 81 c is connected to the negative electrode of the storage battery 5 via the terminal S. The output side (switch unit 4 side) of the bidirectional switching elements 81 a to 81 c is connected to the switch 41 of the switch unit 4 via the terminal U. The switch unit 4 is an example of the “selection switch” in the present invention.

  The input side of the bidirectional switching element 81 d is connected to one end 10 a of the reactor 10. In addition, the input side of the bidirectional switching element 81 e is connected to the other end 10 b of the reactor 10. The input side of the bidirectional switching element 81 f is connected to the negative electrode of the storage battery 5 via the terminal S. The output sides of the bidirectional switching elements 81 d to 81 f are connected to the switch 42 of the switch unit 4 via the terminal V.

  The output sides of the bidirectional switching elements 81 a to 81 c are connected to one electrode 82 a of the capacitor 82. The output sides of the bidirectional switching elements 81 d to 81 f are connected to the other electrode 82 b of the capacitor 82. The capacitor 82, together with the reactor 10, constitutes a boost chopper circuit in a boost mode in which a DC voltage described later is boosted and converted into an AC voltage, and in a step-down mode in which a DC voltage described later is stepped down and converted into an AC voltage. Configure the filter.

  In addition, the snubber circuit 9 includes a rectifier circuit 91 connected to the input side of the power converter 8 and a rectifier circuit 92 connected to the output side of the power converter 8, as shown by a one-dot chain line in FIG. And a capacitor 93. Further, the snubber circuit 9 has a function as a protection circuit that absorbs a surge voltage generated when the gate of the bidirectional switching elements 81 a to 81 f of the power conversion unit 8 is cut off to the output voltage that drives the load 7. The output side of the rectifier circuit 91 and the output side of the rectifier circuit 92 are connected.

  The rectifier circuit 91 includes six diodes 91a to 91f. The diodes 91a to 91f are examples of the “rectifying element” in the present invention. The output side (cathode side) of the diode 91a and the input side (anode side) of the diode 91b are connected, and the input side of the bidirectional switching elements 81a and 81d and the one end 10a of the reactor 10 are connected to the connection point. Has been. The output side of the diode 91c and the input side of the diode 91d are connected, and the input side of the bidirectional switching elements 81b and 81e and the other end 10b of the reactor 10 are connected to the connection point. The output side of the diode 91e and the input side of the diode 91f are connected, and the input side of the bidirectional switching elements 81d and 81f and the negative electrode of the storage battery 5 are connected to the connection point via the terminal S.

  The rectifier circuit 92 includes four diodes 92a to 92d. The diodes 92a to 92d are examples of the “rectifying element” in the present invention. The output side (cathode side) of the diode 92a is connected to the input side (anode side) of the diode 92b, and the outputs of the three bidirectional switching elements 81a to 81c are connected to the connection point. The output side of the diode 92c and the input side of the diode 92d are connected, and the outputs of the three bidirectional switching elements 81d to 81f are connected to the connection point.

  The output sides of the diodes 91b, 91d and 91f and the output sides of the diodes 92b and 92d are connected to one electrode 93a of the capacitor 93. The input sides of the diodes 91a, 91c and 91e and the input sides of the diodes 92a and 92c are connected to the other electrode 93b of the capacitor 93. The voltage obtained by adding the surge voltage generated when the gates of the bidirectional switching elements 81a to 81f are cut off to the output voltage for driving the load 7 is rectified by the rectifier circuits 91 and 92 of the snubber circuit 9 and charged to the capacitor 93. It is configured as follows. The voltage charged in the capacitor 93 is configured to be supplied to the main control power supply 31 via the selection circuit 33 as will be described later.

  The terminal S1 of the switch 41 is connected to the output side of the bidirectional switching elements 81a to 81c. The terminal S2 of the switch 41 is connected to the commercial power source 6 via the terminal U1, the terminal S3 is connected to the load 7 via the terminal U2, and the output side of the bidirectional switching elements 81a to 81c is connected to the commercial power source 6. Or is connected to the load 7. The terminal S4 of the switch 42 is connected to the output side of the bidirectional switching elements 81d to 81f. The terminal S5 of the switch 42 is connected to the commercial power supply 6 via the terminal V1, the terminal S6 is connected to the load 7 via the terminal V2, and the output side of the bidirectional switching elements 81d to 81f is connected to the commercial power supply 6. Or is connected to the load 7.

  The switches 41 and 42 are configured to switch and connect the load 7 to the output of the power conversion unit 8 (bidirectional switching elements 81a to 81f) in a normal operation of discharging the storage battery 5. At this time, the power supply device 100 converts the DC voltage of the storage battery 5 into an AC voltage having a larger amplitude (voltage) and frequency than the DC voltage by the power converter 8 and supplies the AC voltage to the load 7. In addition, at the time of discharge of the storage battery 5, said stop, starting, and normal operation | movement are included. The switches 41 and 42 use the commercial power source 6 by switching so that the commercial power source 6 is connected to the output side of the power conversion unit 8 (bidirectional switching elements 81a to 81f) when the storage battery 5 is charged. Thus, the storage battery 5 and the capacitor 93 of the snubber circuit 9 are charged. In addition, the operation | movement at the time of normal driving | operation (at the time of discharge) and charge of the power supply device 100 is mentioned later.

  The input side of the DC / DC converter 32 of the control power supply unit 3 is connected to the positive electrode and the negative electrode of the storage battery 5. The output side of the DC / DC converter 32 is connected to the selection circuit 33. Here, in the present embodiment, the DC / DC converter 32 is configured to convert the voltage supplied from the storage battery 5 into a predetermined voltage. Specifically, the DC / DC converter 32 is configured to boost the voltage of 40V supplied from the storage battery 5 to about 150V (150V to 160V). The voltage of 40 V supplied from the storage battery 5 is an example of the “first DC voltage” in the present invention. The voltage of about 150 V obtained by boosting the voltage of the storage battery 5 by the DC / DC converter 32 is an example of the “second DC voltage” in the present invention.

  In the present embodiment, one end on the output side of the DC / DC converter 32 is connected to the anode of the diode 33 a of the selection circuit 33, and the other end on the output side is directly connected to the main control power supply 31 via the selection circuit 33. The other electrode 93b of the capacitor 93 is connected to the connection point. The cathode of the diode 33a is connected to the main control power supply 31, and one electrode 93a of the capacitor 93 is connected to the connection point. As described above, the selection circuit 33 selectively supplies the higher voltage of the DC voltage of the DC / DC converter 32 and the DC charging voltage charged in the capacitor 93 of the snubber circuit 9 to the main control power supply 31. It is configured to have a function.

  In this embodiment, the voltage of about 150 V boosted by the DC / DC converter 32 is higher than the DC charging voltage (voltage higher than 160 V) after completion of charging of the capacitor 93 of the snubber circuit 9 during normal operation. It is set to be low. The selection circuit 33 including the diode 33a is configured to supply a voltage of about 150 V boosted by the DC / DC converter 32 to the main control power supply 31 at least when the power conversion unit 8 is started and stopped. Yes.

  Next, with reference to FIGS. 2 to 9, details of the step-up operation and the step-down operation when discharging from the storage battery 5 to the load 7 will be described. In order to convert a DC voltage of 40 V to a 100 V single-phase AC voltage having a frequency of 50 Hz or 60 Hz, for example, when the DC voltage of the storage battery 5 is smaller than the instantaneous value of the single-phase AC voltage, the voltage is boosted, When the DC voltage of the storage battery 5 is larger than the instantaneous value of the single-phase AC voltage, it is necessary to step down. Therefore, a positive step-down mode, a positive step-up mode, a negative step-down mode, and a negative step-up mode are required within one cycle in which an AC voltage is output from the storage battery 5 to the load 7, and bidirectional switching according to each mode is required. The control circuit 2 needs to output the gate signals of the elements 81a to 81f. Hereinafter, each mode will be described in detail. 2 to 9, the control circuit unit 2, the control power supply unit 3, the switch unit 4 and the like are omitted for simplification of the drawings.

(Positive buck mode)
When the 40V DC voltage is stepped down to output a single-phase AC voltage, the control circuit 2 always turns on the bidirectional switching element 81a of the power converter 8 as shown in FIGS. . Further, the control circuit 2 turns on / off the bidirectional switching elements 81e and 81f so that one of them always turns on. As shown in FIG. 2, when the bidirectional switching element 81f is on, a current flows through the storage battery 5, the reactor 10, the bidirectional switching element 81a, the load 7, and the bidirectional switching element 81f. As shown in FIG. 3, when the bidirectional switching element 81e is on, a current flows through the reactor 10, the bidirectional switching element 81a, the load 7, and the bidirectional switching element 81e. The control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 2 and 3, whereby the DC voltage of the storage battery 5 is stepped down and supplied to the load 7. Here, when the DC voltage of the storage battery 5 is VDC and the ratio of the time during which the bidirectional switching element 81f is in the on state is Ton (= on time / (on time + off time)), the load 7 The supplied voltage instantaneous value Vout is expressed by the following equation (1).

  Vout = VDC × Ton (1)

(Positive boost mode)
When boosting the DC voltage of 40V and outputting a single-phase AC voltage, the control circuit 2 always turns on the bidirectional switching element 81a of the power converter 8 as shown in FIGS. . Further, the control circuit 2 turns on / off the bidirectional switching elements 81c and 81f so that one of them is always on. As shown in FIG. 4, when the bidirectional switching element 81c is on, a current flows through the storage battery 5, the reactor 10, the bidirectional switching element 81a, and the bidirectional switching element 81c. As shown in FIG. 5, when the bidirectional switching element 81f is on, a current flows through the storage battery 5, the reactor 10, the bidirectional switching element 81a, the load 7, and the bidirectional switching element 81f. When the control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 4 and 5, the DC voltage of the storage battery 5 is boosted and supplied to the load 7. Here, when the direct-current voltage of the storage battery 5 is VDC and the ratio of the time during which the bidirectional switching element 81c is on is Ton, the instantaneous voltage value Vout supplied to the load 7 is expressed by the following equation (2). Represented.

  Vout = VDC / (1-Ton) (2)

(Negative step-down mode)
A 40V DC voltage is stepped down, and a negative voltage (a voltage in the opposite direction) is applied to the load 7. Specifically, as shown in FIGS. 6 and 7, the control circuit 2 always turns on the bidirectional switching element 81 d of the power conversion unit 8. Further, the control circuit 2 turns on / off the bidirectional switching elements 81b and 81c so that one of them always turns on. As shown in FIG. 6, when the bidirectional switching element 81c is on, a current flows through the storage battery 5, the reactor 10, the bidirectional switching element 81d, the load 7, and the bidirectional switching element 81c. As shown in FIG. 7, when the bidirectional switching element 81b is on, a current flows through the reactor 10, the bidirectional switching element 81d, the load 7, and the bidirectional switching element 81b. The control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 6 and 7, whereby the DC voltage of the storage battery 5 is stepped down and supplied to the load 7. At this time, the direction of the voltage applied to the load 7 is opposite (negative voltage) to that in the positive step-down mode. The instantaneous voltage value applied to the load 7 is expressed by the above equation (1).

(Negative boost mode)
The DC voltage of 40V is boosted, and a negative voltage (a reverse voltage) is applied to the load 7. Specifically, as shown in FIGS. 8 and 9, the control circuit 2 always turns on the bidirectional switching element 81 d of the power conversion unit 8. Further, the control circuit 2 turns on / off the bidirectional switching elements 81c and 81f so that one of them is always on. As shown in FIG. 8, when the bidirectional switching element 81f is on, a current flows through the storage battery 5, the reactor 10, the bidirectional switching element 81d, and the bidirectional switching element 81f. As shown in FIG. 9, when the bidirectional switching element 81c is on, a current flows through the storage battery 5, the reactor 10, the bidirectional switching element 81d, the load 7, and the bidirectional switching element 81c. When the control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 8 and 9, the DC voltage of the storage battery 5 is boosted and supplied to the load 7. At this time, the direction of the voltage applied to the load 7 is opposite to that in the positive boost mode (negative voltage). The instantaneous voltage value applied to the load 7 is expressed by the above equation (2).

  Next, with reference to FIGS. 10 to 17, the details of the step-up operation and the step-down operation when charging the storage battery 5 from the commercial power source 6 will be described. For example, in order to convert from a single-phase AC voltage of a commercial power supply of 100 V having a frequency of 50 Hz or 60 Hz to a DC voltage of 40 V, when the instantaneous value of the single-phase AC voltage is lower than the DC voltage of the storage battery 5, It is necessary to boost the pressure. Further, when the instantaneous value of the single-phase AC voltage is higher than the DC voltage of the storage battery 5, it is necessary to step down. Therefore, a positive step-down mode, a positive step-up mode, a negative step-down mode, and a negative step-up mode are required within one cycle of the single-phase AC voltage of the commercial power supply 6, and the bidirectional switching element 81a corresponding to each mode is required. The control circuit 2 needs to output a gate signal of ˜81f. Hereinafter, each mode will be described in detail. 10 to 17, the control circuit unit 2, the control power supply unit 3, the switch unit 4 and the like are omitted for simplification of the drawings.

(Positive buck mode)
When the ac voltage is stepped down and the storage battery 5 of 40V is charged, the control circuit 2 always turns on the bidirectional switching element 81a of the power converter 8 as shown in FIGS. Further, the control circuit 2 turns on / off the bidirectional switching elements 81c and 81f so that one of them is always on. As shown in FIG. 10, when the bidirectional switching element 81f is on, a current flows through the commercial power supply 6, the bidirectional switching element 81a, the reactor 10, the storage battery 5, and the bidirectional switching element 81f. As shown in FIG. 11, when the bidirectional switching element 81c is on, a current flows through the reactor 10, the storage battery 5, the bidirectional switching element 81c, and the bidirectional switching element 81a. When the control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 10 and 11, the AC voltage of the commercial power source 6 is stepped down and the storage battery 5 is charged. The voltage VDC applied to the storage battery 5 is the voltage instantaneous value of the commercial power supply 6 Vout, and the time ratio during which the bidirectional switching element 81f is on is Ton (= on time / (on time + off time). )), It is expressed by the following formula (3).

  VDC = Vout × Ton (3)

(Positive boost mode)
When boosting the AC voltage to charge the 40 V storage battery 5, the control circuit 2 always turns on the bidirectional switching element 81 a of the power converter 8 as shown in FIGS. 12 and 13. Further, the control circuit 2 turns on / off the bidirectional switching elements 81e and 81f so that one of them always turns on. As shown in FIG. 12, when the bidirectional switching element 81e is on, a current flows through the commercial power supply 6, the bidirectional switching element 81a, the reactor 10, and the bidirectional switching element 81e. As shown in FIG. 13, when the bidirectional switching element 81f is on, a current flows through the commercial power supply 6, the bidirectional switching element 81a, the reactor 10, the storage battery 5, and the bidirectional switching element 81f. When the control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 12 and 13, the AC voltage of the commercial power source 6 is boosted and the storage battery 5 is charged. The voltage VDC applied to the storage battery 5 is expressed by the following equation (4), where Vout is the instantaneous value of the voltage of the commercial power supply 6 and Ton is the ratio of the time during which the bidirectional switching element 8e is on. It is.

  VDC = Vout / (1-Ton) (4)

(Negative step-down mode)
When the AC voltage is stepped down to charge the storage battery 5 of 40 V, the control circuit 2 always turns on the bidirectional switching element 81 d of the power conversion unit 8 as shown in FIGS. 14 and 15. Further, the control circuit 2 turns on / off the bidirectional switching elements 81c and 81f so that one of them is always on. When the bidirectional switching element 81c is on, the bidirectional switching element 81f is turned off. As shown in FIG. 14, when the bidirectional switching element 81c is on, a current flows through the commercial power supply 6, the bidirectional switching element 81d, the reactor 10, the storage battery 5, and the bidirectional switching element 81c. As shown in FIG. 15, when the bidirectional switching element 81f is on, a current flows through the reactor 10, the storage battery 5, the bidirectional switching element 81f, and the bidirectional switching element 81d. When the control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 14 and 15, the AC voltage of the commercial power source 6 is stepped down and the storage battery 5 is charged. In addition, the magnitude | size of the voltage applied to the storage battery 5 is represented by said Formula (3).

(Negative boost mode)
When boosting the AC voltage to charge the storage battery 5 of 40V, the control circuit 2 always turns on the bidirectional switching element 81d of the power converter 8 as shown in FIGS. Further, the control circuit 2 turns on / off the bidirectional switching elements 81b and 81c so that one of them always turns on. When the bidirectional switching element 81b is on, the bidirectional switching element 81c is turned off. As shown in FIG. 16, when the bidirectional switching element 81b is on, a current flows through the commercial power supply 6, the bidirectional switching element 81d, the reactor 10, and the bidirectional switching element 81b. As shown in FIG. 17, when the bidirectional switching element 81c is on, a current flows through the commercial power supply 6, the bidirectional switching element 81d, the reactor 10, the storage battery 5, and the bidirectional switching element 81c. When the control circuit 2 outputs a gate signal so as to repeat the states of FIGS. 16 and 17, the AC voltage of the commercial power supply 6 is boosted and the storage battery 5 is charged. In addition, the magnitude | size of the voltage applied to the storage battery 5 is represented by said Formula (4).

  Next, the operation of the selection circuit 33 during the normal operation of the power supply device 100 according to the first embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 18, when the user of the power supply device 100 shown in the first embodiment performs the normal operation of the power supply device 100, the switch unit 4 is switched and the other end of the switch 41 is connected to the terminal S2. At the same time, the other end of the switch 42 is connected to the terminal S4. Then, by turning on / off the bidirectional switching elements 81a to 81f of the power conversion unit 8 by the control circuit unit 2, the DC voltage of the storage battery 5 input from the terminals R and S is as described above. , Converted to a single-phase AC voltage having a larger amplitude (voltage) and frequency than the DC voltage. The converted single-phase AC voltage is supplied to the load 7 via the terminal U and the terminal V. A voltage obtained by adding a surge voltage generated when the gates of the bidirectional switching elements 81a to 81f are cut off is rectified via the rectifier circuit 91 or 92 and charged to the capacitor 93 of the snubber circuit 9. At this time, the DC charging voltage of the capacitor 93 is higher than 160V.

  Further, the 40 V DC voltage of the storage battery 5 is boosted to 150 V or more and 160 V or less by the DC / DC converter 32 and is output to the selection circuit 33. The higher voltage of the DC voltage output from the DC / DC converter 32 and the DC charging voltage of the capacitor 93 of the snubber circuit 9 is selected by the selection circuit 33 including the diode 33a, and the main control power supply 31 is selected. To be supplied. Here, in the present embodiment, during the normal operation of the power supply device 100, the DC charging voltage (voltage higher than 160V) of the capacitor 93 of the snubber circuit 9 is the DC voltage output from the DC / DC converter 32 ( Higher than 150V and lower than 160V). Therefore, during the normal operation of the power supply device 100, the DC charging voltage of the capacitor 93 of the snubber circuit 9 is selected by the selection circuit 33 and supplied to the main control power supply 31. The main control power supply 31 converts the voltage input from the selection circuit 33 into a voltage determined by the input voltage and supplies the voltage to the control circuit unit 2. For example, in order to supply the voltage necessary for the main power supply device 31 to drive the bidirectional switching elements 81 a to 81 f to the control circuit 2, the main control apparatus 31 requires a DC voltage of 140 V or more as an input of the main control power supply 31. Assuming that the power supply 31 is designed, in the above state, the main control power supply 31 is supplied with an input voltage necessary to drive the bidirectional switching elements 81a to 81f. As a result, the control circuit unit 2 receives supply of a voltage necessary for driving the bidirectional switching elements 81 a to 81 f of the power conversion unit 8 from the main control power supply 31, and drives and controls the power conversion unit 8.

  Next, with reference to FIG. 19, the operation of the selection circuit 33 when the power supply device 100 according to the first embodiment of the present invention is started and stopped will be described.

  As shown in FIG. 19, at the time of starting the power supply device 100, the other end of the switch 41 is connected to the terminal S2 as in the normal operation. The other end of the switch 42 is connected to the terminal S4. At the time of start-up (when a little time has passed since the start-up), as the bidirectional switching elements 81a to 81f are turned on / off, charge accumulation in the capacitor 93 proceeds, and the voltage of the snubber circuit 9 becomes It becomes larger than the voltage 40V of the storage battery 5 before starting. For this reason, at the beginning of startup, the voltage charged in the capacitor 93 of the snubber circuit 9 is lower than 150V.

  On the other hand, the DC voltage of 40 V of the storage battery 5 is boosted by the DC / DC converter 32 to 150 V or more and 160 V or less as in the normal operation. Therefore, when the power supply device 100 is started, the DC voltage (150 V or more and 160 V or less) output from the DC / DC converter 32 is higher than the DC charging voltage (voltage lower than 150 V) of the capacitor 93 of the snubber circuit 9. Since it is high, the DC voltage output from the DC / DC converter 32 is selected by the selection circuit 33 and supplied to the main control power supply 31. Therefore, as in the normal operation, the main control power supply 31 needs to have a DC voltage of 140 V or more as an input to the main control power supply 31 in order to supply the control circuit 2 with the voltage necessary for driving the bidirectional switching elements 81a to 81f. As a result, a voltage necessary to drive the bidirectional switching elements 81a to 81f of the power converter 8 is supplied from the main control power supply 31 to the control circuit unit 2.

  Further, as time elapses from the time of startup, the DC charging voltage of the capacitor 93 of the snubber circuit 9 increases, and the DC charging voltage of the capacitor 93 of the snubber circuit 9 is output from the DC / DC converter 32. When the voltage is higher than the generated DC voltage (during normal operation), the DC charging voltage of the capacitor 93 is selected by the selection circuit 33 and supplied to the main control power supply 31 as described above.

  Further, when the power supply device 100 is stopped, the on / off of the bidirectional switching elements 81a to 81f is stopped, so that no surge voltage is generated when the gates of the bidirectional switching elements 81a to 81f are cut off. For this reason, the DC charging voltage of the capacitor 93 of the snubber circuit 9 gradually decreases toward the DC voltage 40V of the storage battery 5 due to the consumption of energy by the main control power supply 31. Thereby, when the power supply apparatus 100 is stopped, the DC voltage (150 V or more and 160 V or less) output from the DC / DC converter 32 becomes higher than the DC charging voltage (40 V) of the capacitor 93 of the snubber circuit 9. The DC voltage output from the / DC converter 32 is selected by the selection circuit 33 including the diode 33 a and supplied to the main control power supply 31. In addition, since it is not necessary to control the bidirectional switching elements 81a to 81f at the time of stop, there is no problem even if power is not supplied from the storage battery 5 to the main control power supply 31.

  Next, the operation of the selection circuit 33 during charging of the storage battery 5 according to the first embodiment of the present invention will be described with reference to FIG.

  Charging of the power supply device 100 is performed by the user of the power supply device 100 of the first embodiment when the amount of charge of the storage battery 5 becomes empty. At this time, as shown in FIG. By switching, the other end of the switch 41 is connected to the terminal S1. Further, the other end of the switch 42 is connected to the terminal S3. Thereby, a single-phase AC voltage of, for example, 100 V of the commercial power supply 6 is input to the power conversion unit 8 via the terminal U and the terminal V. The single-phase AC voltage of the commercial power supply 6 input to the power conversion unit 8 is converted into a DC voltage by the power conversion unit 8 and input to the storage battery 5. Thereby, the storage battery 5 is charged. The single-phase AC voltage of the commercial power supply 6 is input to the rectifier circuit 92 of the snubber circuit 9. Then, the single-phase AC voltage of the commercial power supply 6 is rectified and converted into a DC voltage, and the capacitor 93 of the snubber circuit 9 is charged. Note that the DC charging voltage of the capacitor 93 of the snubber circuit 9 is 141 V in the first embodiment corresponding to the peak voltage of the commercial power supply 6, and during the charging operation, the surge at the time when the gates of the bidirectional switching elements 81a to 81f are cut off. The voltage is added and becomes higher than 160V.

  Further, since the charge amount of the storage battery 5 is empty and its voltage is substantially equal to 0V, the voltage supplied from the storage battery 5 and boosted by the DC / DC converter 32 is also close to 0V. Therefore, as in the normal operation, the DC charging voltage (141 V) of the capacitor 93 of the snubber circuit 9 is selected by the selection circuit 33 and supplied to the main control power supply 31. Since the input voltage of the main control power supply 31 is 140 V or higher, a voltage necessary for driving the bidirectional switching elements 81 a to 81 f of the power conversion unit 8 is supplied from the main control power supply 31 to the control circuit unit 2. Accordingly, the bidirectional switching elements 81 a to 81 f of the power conversion unit 8 are driven and controlled by the control circuit unit 2.

  In the first embodiment, as described above, the DC / DC converter 32 is configured to boost a voltage of 40 V to a voltage of about 150 V (150 V or more and 160 V or less), and the DC / DC converter 32 boosts the voltage. The selection circuit 33 that selects the higher voltage of the DC voltage thus generated and the DC charging voltage charged in the capacitor 93 of the snubber circuit 9 and supplies the selected voltage to the main control power supply 31, thereby providing the capacitor 93 of the snubber circuit 9. When the power conversion unit 8 is started and stopped, the voltage obtained by boosting the DC voltage based on the storage battery 5 is selected by the selection circuit 33 and supplied to the main control power supply 31, so that the power conversion unit 8 is started. Sometimes, the power converter 8 can be driven and controlled. Further, even when the voltage of the storage battery 5 is not sufficiently large to control the power conversion unit 8, the voltage of the storage battery 5 is boosted by the DC / DC converter 32, so that the power conversion unit 8 is reliably driven. Can be controlled.

  In the first embodiment, as described above, the DC voltage (150 V or more and 160 V or less) boosted by the DC / DC converter 32 is used for DC charging during normal operation and charging operation of the capacitor 93 of the snubber circuit 9. It is set to be lower than the voltage (voltage higher than 160V). Thereby, during the charging operation and the normal operation of the storage battery 5, the direct current voltage charged in the capacitor 93 of the snubber circuit 9 is selected by the selection circuit 33 and supplied to the main control power supply 31. 93 can be used as a power source for driving the power converter 8.

  In the first embodiment, as described above, the voltage of the capacitor 93 of the snubber circuit 9 becomes low when the power supply device 100 (power conversion unit 8) is started and stopped, so that the voltage is boosted by the DC / DC converter 32. The selected DC voltage is selected by the selection circuit 33 and supplied to the main control power supply 31. At the time of start-up, the state where the voltage of the capacitor 93 of the snubber circuit 9 is lower than the DC voltage boosted by the DC / DC converter 32 lasts only for a short time, and at the time of stop, the bidirectional switching elements 81a to 81f need to be driven. There is no. Accordingly, it is possible to reduce the capacity of the DC / DC converter 32 that supplies power from the storage battery 5 to the main control power supply 31 when starting and stopping.

  In the first embodiment, the power conversion unit 8 is connected to the one end 10 a of the reactor 10, the other end 10 b of the reactor 10, and the negative electrode of the storage battery 5 as described above. Thereby, the voltage of the storage battery 5 can be boosted or lowered by the reactor 10 and supplied to the load 7. Further, the storage battery 5 can be charged by increasing or decreasing the voltage of the commercial power supply 6.

  In the first embodiment, as described above, the selection circuit 33 is configured by one diode 33a, so that the DC voltage based on the storage battery 5 and the capacitor 93 of the snubber circuit 9 are charged with a simple configuration. A higher voltage than the DC charging voltage can be supplied to the main control power supply 31.

  Moreover, in 1st Embodiment, the switch part 4 which selectively connects the load 7 and the commercial power source 6 with respect to the output of the power converter part 8 is provided as mentioned above. And when charging the storage battery 5, a user switches the switch part 4 so that the commercial power supply 6 may be connected with respect to the output of the power converter part 8. As a result, the capacitor 93 of the snubber circuit 9 is also charged by the commercial power source 6. As a result, when the storage battery 5 is charged by the power conversion unit 8 using the commercial power source 6, the power conversion unit 8 can be driven and controlled using the capacitor 93 of the snubber circuit 9 as a power source.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In the second embodiment, unlike the first embodiment in which the voltage of the storage battery 5 is smaller than the voltage of the commercial power supply 6 (load 7), the voltage of the storage battery 5 is substantially equal to the peak voltage of the commercial power supply 6 (load 7). .

  As shown in FIG. 21, the power converter 8a of the power supply device 101 according to the second embodiment is provided with four bidirectional switching elements 81a, 81c, 81d and 81f. In the power conversion unit 8a of the power supply device 101, the voltage of the storage battery 5 is substantially equal to the peak voltage of the commercial power supply 6 (load 7), and therefore it is not necessary to boost the voltage of the storage battery 5. Thus, unlike the power conversion unit 8 of the first embodiment, the bidirectional switching elements 81b and 81e are not provided. As a result, the rectifier circuit 91 of the snubber circuit 9a is composed of four diodes 91a, 91b, 91e and 91f, unlike the first embodiment including six diodes.

  Moreover, the storage battery 5 has a voltage of, for example, 150 V that is substantially equal to the peak voltage of the commercial power source 6. Commercial power supply 6 is an AC power supply having a voltage (effective voltage) of 110 V, for example. The load 7 is a load that requires an AC voltage of 100 V, for example. In order for the main control power supply 31 to supply the control circuit 2 with a voltage necessary for driving the bidirectional switching elements 81a, 81c, 81d and 81f, a DC voltage of 140 V or more is required as an input to the main control power supply 31. Thus, it is assumed that the main control power supply 31 is designed. Then, since the storage battery 5 has a voltage of 150 V, the power supply device 101 according to the second embodiment can drive the control circuit unit 2 with the voltage of 150 V of the storage battery 5. As a result, unlike the power supply apparatus 100 (see FIG. 1) of the first embodiment, the DC / DC converter 32 is not provided.

  In the power supply device 101, a capacitor 82 is provided in parallel with the power converter 8a on the output side of the power converter 8a. A reactor 10c is provided between the power converter 8a and the rectifier circuit 92 of the snubber circuit 9a. Is provided. Capacitor 82 and reactor 10c together constitute a filter that smoothes the output voltage of power converter 8a.

  Further, in the power supply device 101, during normal operation during discharging of the storage battery 5, the DC charging voltage (voltage higher than 160 V) of the capacitor 93 of the snubber circuit 9 is higher than the DC voltage (150 V) output from the storage battery 5. Become. Therefore, the DC charging voltage of the capacitor 93 of the snubber circuit 9 is selected by the selection circuit 33 and supplied to the main control power supply 31.

  On the other hand, when the power supply device 101 is stopped, the capacitor 93 of the snubber circuit 9 is charged with the DC voltage (150 V) output from the storage battery 5, and the DC charging voltage of the capacitor 93 becomes the DC voltage (150 V) of the storage battery 5. equal. Therefore, the DC voltage of the storage battery is selected from the selection circuit 33 and supplied to the main control power supply 31. Immediately after the power supply device 101 is started, immediately after the start-up, electric charges start to be accumulated in the capacitor 93 due to a surge voltage when the gates of the bidirectional switching elements 81a, 81c, 81d and 81f are cut off. It starts to become larger than the DC voltage. Therefore, when a voltage difference sufficient to turn on the diode 33a is generated between the DC voltage of the storage battery 5 and the DC voltage of the capacitor 93, the DC voltage of the capacitor 93 is selected by the selection circuit 33, and the main control power supply 31.

  Further, when the storage battery 5 is charged, a commercial power source 6 is connected to the output side. The single-phase AC voltage of the commercial power supply 6 is rectified by the rectifier 92 and converted into a DC voltage, but since the effective value of the single-phase AC voltage is 110V, the DC voltage is 156V. When the power supply device 101 is charged, the voltage of the storage battery 5 is close to 0V. Therefore, the DC voltage of the capacitor 93 is 156V, and the voltage selected by the selection circuit 33 is also the DC voltage 156V of the capacitor 93. It is output from the selection circuit 33 and supplied to the main control power supply 31. As described above, the main control power supply 31 can supply the control circuit 2 with power necessary to drive the bidirectional switching elements 81a, 81c, 81d and 81f even when the power supply apparatus 101 is charged.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG.

  In the third embodiment shown in FIG. 22, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The difference of the third embodiment from the first embodiment is that the selection circuit 34 is configured by a control power supply switching switch 34a, and this switch 34a is configured to be switched in conjunction with switching of the switch unit 4. . The control power supply changeover switch 34 can be realized, for example, by configuring the switches 41 and 42 of the switch unit 4 with the main contact of the contactor and using the auxiliary contact in conjunction with the main contact.

  Further, the storage battery 5 has a DC voltage lower than the voltage of the commercial power supply 6, for example, a voltage of 40 V, as in the first embodiment. The commercial power supply 6 is an AC power supply having a voltage (effective voltage) of, for example, 100 V as in the first embodiment. The load 7 is a load that requires a voltage larger than the commercial power supply, for example, an AC voltage of 200V. In order for the main control power supply 31 to supply the control circuit 2 with voltages necessary for driving the bidirectional switching elements 81a to 81f, for example, a DC voltage of 140 V or more is required as an input of the main control power supply 31. Assume that the main control power supply 31 is designed to allow a voltage (for example, 180 V) higher than the DC voltage of the capacitor 93 of the snubber circuit 9 during the charging operation of the storage battery 5. The DC / DC converter 32 is configured to boost the voltage of 40 V supplied from the storage battery 5 to about 150 V (150 V or more and 160 V or less).

  In the power supply device 102, when the storage battery 5 is discharged, the output voltage of the DC / DC converter 32 is selected by the selection circuit 34 and supplied to the main control power supply 31. During discharging of the storage battery 5, the capacitor 93 of the snubber circuit 9 during normal operation is a voltage obtained by adding a surge voltage generated when the gates of the bidirectional switching elements 81 a to 81 f are cut off to the output voltage that drives the load 7 (higher than 320 V). The battery is always charged by the voltage. Accordingly, when the charging voltage of the capacitor 93 is supplied to the main control power supply 31, the allowable voltage 180V of the main control power supply 31 is exceeded, and the main control power supply 31 becomes an overvoltage failure. The selection circuit 34 always selects the output voltage of the DC / DC converter 32 and supplies it to the main control power supply 31 when the storage battery 5 is discharged in order to avoid the failure of the main control power supply 31. This also allows the main control power supply 31 to supply a voltage necessary for driving the bidirectional switching elements 81 a to 81 f to the control circuit 2 at all times.

  On the other hand, when the storage battery 5 is charged, the selection circuit 34 selects the DC voltage of the capacitor 93 and supplies it to the main control power supply 31. When the storage battery 5 is charged, the capacitor 93 is charged by the commercial power supply 6 when the power supply device 102 is stopped, and the DC voltage is 141V. When the power supply device 102 is activated, charges start to be accumulated in the capacitor 93 due to the surge voltage when the gates of the bidirectional switching elements 81a to 81f are cut off, and the DC voltage rises and eventually exceeds 160V. The voltage is such that it does not reach 180 V, which is the maximum voltage allowed as the 31 input. Accordingly, the selection circuit 34 always selects the DC voltage of the capacitor 93 when the storage battery 5 is charged, so that the main control power supply 31 is required to drive the bidirectional switching elements 81a to 81f to the control circuit 2 at all times. Can supply the correct voltage.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, although the DC / DC converter 32 boosts the voltage output from the storage battery 5 in the first embodiment, the present invention is not limited to this. For example, the DC / DC converter 32 may step down the voltage output from the storage battery 5 to convert the voltage output from the storage battery 5 into a voltage suitable for driving the power conversion unit 8. Good.

  In the first embodiment, the 40V DC voltage of the storage battery 5 is boosted to about 150V by the DC / DC converter 32. However, the present invention is not limited to this. The DC voltage of the storage battery 5 may be a voltage other than 40V. The voltage boosted by the DC / DC converter 32 only needs to be lower than the DC charging voltage after completion of charging of the capacitor 93 of the snubber circuit 9.

  In the first embodiment, the example in which the DC voltage from the storage battery 5 is selected and supplied to the main control power supply 31 at the time of starting and stopping of the power supply apparatus 100 has been shown, but the present invention is limited to this. Absent. In the present invention, even when the DC charging voltage of the capacitor 93 of the snubber circuit 9 becomes lower than the DC voltage boosted by the DC / DC converter 32 during normal operation of the power supply device 100, the DC / DC converter. The DC voltage boosted by 32 is selected and supplied to the main control power supply 31. Further, when the storage battery 5 is charged, the DC / DC converter 32 also boosts the DC charging voltage of the capacitor 93 of the snubber circuit 9 when the DC charging voltage is lower than the DC voltage boosted by the DC / DC converter 32. The selected DC voltage is selected and supplied to the main control power supply 31.

  In the first and second embodiments, the selection circuit 33 of the present invention is configured by one diode 33a. However, the present invention is not limited to this. For example, the selection circuit of the present invention may be constituted by two or more diodes.

5 Storage Battery 6 Commercial Power Supply 7 Load 8, 8a Power Converter 9, 9a Snubber Circuit 10 Reactor 31 Main Control Power Supply (Control Power Supply)
32 DC / DC converter (DC voltage converter)
33 Selection circuit 33a Diode 41, 42 Switch (selection switch)
81a, 81b, 81c, 81d, 81e, 81f Bidirectional switching element 91a, 91b, 91c, 91d, 91e, 91f Diode (rectifier element)
92a, 92b, 92c, 92d Diode (rectifier element)
93 Capacitor 100, 101, 102 Power supply

Claims (9)

A storage battery as a DC power source is connected to the input side, a load or a commercial power source is selected and connected to the output side, and a power conversion unit capable of bidirectional power conversion,
A snubber circuit that includes a rectifier element and a capacitor, rectifies an output AC voltage by at least the rectifier element, charges the capacitor, and absorbs a surge voltage generated during operation of the power converter;
A main control power supply for generating a power supply voltage for driving the power converter;
And a selection circuit that selects a higher voltage of a DC voltage based on the storage battery and a DC charging voltage charged in a capacitor of the snubber circuit and supplies the selected voltage to the main control power supply.   The power supply device according to claim 1, wherein the power conversion unit includes a plurality of bidirectional switching elements arranged in a matrix. A reactor provided between the positive electrode of the storage battery and the power converter;
A capacitor connected in parallel with the power converter on the output side of the power converter;
The power conversion unit includes a plurality of bidirectional switching elements arranged in a matrix, and is connected to one end of the reactor, the other end of the reactor, and a negative electrode of the storage battery. The power supply device described in 1. A DC voltage converter that converts the first DC voltage from the storage battery into a second DC voltage;
The selection circuit is configured to select a higher voltage of the second DC voltage converted by the DC voltage converter and a DC charging voltage of a capacitor of the snubber circuit and supply the selected voltage to the main control power supply. The power supply device according to any one of claims 1 to 3.   The power supply apparatus according to claim 4, wherein the DC voltage conversion unit is configured to boost the first DC voltage to the second DC voltage.   The power supply device according to claim 5, wherein the second DC voltage boosted by the DC voltage conversion unit is set to be lower than a DC charging voltage of a capacitor of the snubber circuit.   At least when the power converter is started and stopped, the second DC voltage boosted by the DC voltage converter is selected by the selection circuit and supplied to the main control power supply. Item 7. The power supply device according to Item 5 or 6.   The power supply device according to claim 1, wherein the selection circuit is configured by a diode. A selection switch for selectively connecting the load or the commercial power supply to the output of the power converter;
When the storage battery is charged, the snubber circuit capacitor is charged by the commercial power source by switching the selection switch so that the commercial power source is connected to the output of the power converter, and the power converter is The AC voltage of a power supply is converted into a DC voltage to charge the storage battery, and the snubber circuit is configured to absorb a surge voltage generated when the gate of the bidirectional switching element of the power conversion unit is cut off. The power supply device of any one of -8.

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