WO2014155540A1

WO2014155540A1 - Inverter device and inverter system

Info

Publication number: WO2014155540A1
Application number: PCT/JP2013/058848
Authority: WO
Inventors: 和徳畠山; 篠本　洋介; 崇山川
Original assignee: 三菱電機株式会社
Priority date: 2013-03-26
Filing date: 2013-03-26
Publication date: 2014-10-02
Also published as: JP6300785B2; JPWO2014155540A1

Abstract

In order to reduce power loss at the time of operating an inverter device by means of a commercial power supply and a distributed power supply system, an inverter device (200) of the present invention is provided with: an AC-DC conversion unit (210) (alternating current-direct current conversion unit) that converts alternating currents into direct currents and outputs the currents; a DC-AC conversion unit (220) (direct current-alternating current conversion unit) that converts direct currents into alternating currents and outputs the currents to an inductive load; and a direct current switch unit connecting terminal (240) that is led out between the AC-DC conversion unit (210) and the DC-AC conversion unit (220). The direct current switch unit connecting terminal (240) is electrically connected to a direct current power supply (600) via a direct current switch unit (320).

Description

Inverter device and inverter system

The present invention relates to an inverter device and an inverter system including the inverter device.

In recent years, a distributed power system has been studied as a countermeasure against a decrease in the amount of power supplied in an emergency such as a disaster. Such a distributed power supply system generally stores DC power when the amount of power required is small (for example, at night) and converts the stored DC power into AC power using a power converter. It is. For example, Patent Document 1 discloses a power supply system that supplies power from at least one of a commercial power supply source, a solar power generation unit, a fuel cell power generation unit, and a power storage unit, and a blackout or the like of the commercial power supply source occurs. In such a case, it is disclosed that a commercial power supply source is disconnected by a switch, and the power storage unit starts a self-sustained operation and supplies power to a load via another switch.

JP 2011-188607 A

However, according to the prior art, when operating a residential load with a distributed power supply system, a DC-DC converter that steps up and down DC voltage and a DC-AC converter that converts DC to AC, For example, it is necessary to supply a voltage to an in-home load after generating a voltage such as AC 100V equivalent to the power system. Most refrigerators and air conditioners are equipped with inverters from the viewpoint of reducing power consumption in recent years, and include AC-DC converters and DC-AC converters that convert alternating current into direct current. Therefore, power loss due to a total of four converters occurs.

The present invention has been made in view of the above, and an object thereof is to reduce power loss when an inverter device is operated by a commercial power source and a distributed power source system.

In order to solve the above-described problems and achieve the object, the inverter device of the present invention includes an AC / DC converter that converts AC to DC and outputs, and a DC that converts DC to AC and outputs it to an inductive load. An AC conversion unit, and a DC switching unit connection terminal drawn from between the AC / DC conversion unit and the DC / AC conversion unit.

According to the present invention, it is possible to reduce the power loss when the inverter device is operated by the commercial power source and the distributed power source system.

FIG. 1 is a diagram illustrating an inverter system according to the first embodiment. FIG. 2 is a diagram illustrating a detailed configuration of the inverter device, the AC power source, and the DC power source included in the inverter system according to the first embodiment. FIG. 3A is a diagram for explaining a power supply path during normal operation in the comparative example. FIG. 3B is a diagram for explaining a power supply path during normal operation in the configuration according to the first embodiment. FIG. 4A is a diagram for explaining an emergency power supply path in a comparative example. FIG. 4B is a diagram for explaining an emergency power supply path in the configuration according to the first embodiment. FIG. 5 is a diagram illustrating a power supply path when power is supplied from both the AC power supply and the DC power supply in the configuration according to the first embodiment. FIG. 6 is a diagram illustrating an inverter system according to the second embodiment. FIG. 7 is a diagram illustrating a power supply path during normal operation in the configuration according to the second embodiment. FIG. 8 is a diagram illustrating an emergency power supply path in the configuration according to the second embodiment. FIG. 9 is a diagram illustrating a power supply path when power is supplied from both the AC power supply and the DC power supply in the configuration according to the second embodiment.

Hereinafter, embodiments of an inverter device and an inverter system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an inverter system according to the present embodiment. A power supply switching inverter system 100 shown in FIG. 1 includes an inverter device 200, an opening / closing unit 300, and an opening / closing control unit 400, and is electrically connected to an AC power source 500 and a DC power source 600.

The inverter device 200 includes an AC-DC conversion unit 210 (AC / DC conversion unit), a DC-AC conversion unit 220 (DC / AC conversion unit), an inductive load 230, and a DC switching unit connection terminal 240. An AC-DC converter 210 and an inductive load 230 are electrically connected to the DC-AC converter 220, respectively.

The opening / closing part 300 includes an AC opening / closing part 310 and a DC opening / closing part 320. The AC switching unit 310 is electrically connected to the AC power source 500 and the AC-DC conversion unit 210. Further, the direct current switching unit 320 is electrically connected to the direct current power source 600, the AC-DC conversion unit 210, and the DC-AC conversion unit 220.

The AC switching unit 310 and the DC switching unit 320 are controlled by the opening / closing control unit 400 so as to be in an open state or a closed state. That is, the wiring system input to the inverter device 200 includes a wiring system to which AC power is supplied and a wiring system to which DC power is supplied. 400 is determined by controlling the opening and closing unit 300.

The AC power supply 500 includes a commercial power supply 510 and an AC-DC converter 520. The AC power supply 500 supplies an AC voltage generated by the commercial power supply 510 or an AC voltage obtained by converting the DC voltage of the DC power supply 600 by the AC-DC conversion unit 520 to the AC switching unit 310.

The DC power supply 600 includes a DC voltage source 610 (battery or the like) and a DC-DC converter 620. The DC power supply 600 converts the DC voltage of the DC voltage source 610 into a predetermined DC voltage by the DC-DC conversion unit 620 and supplies it to the AC-DC conversion unit 520 and the DC switching unit 320. Note that the DC voltage source 610 may be a storage battery mounted on an electric vehicle.

FIG. 2 is a diagram showing a detailed configuration of the inverter device 200, the AC power supply 500, and the DC power supply 600 included in the power supply switching inverter system 100. The AC-DC converter 210 includes a reactor 211, diodes 212a to 212d, and a capacitor 213, and converts an AC voltage supplied from the AC power supply 500 through the AC switching unit 310 into a DC voltage. However, the AC-DC converter 210 is not limited to the illustrated configuration, and may be any configuration capable of converting from alternating current to direct current.

Also, the DC-AC converter 220 converts the direct current from the AC-DC converter 210 into an alternating current having a predetermined voltage value and frequency by using the six switching elements 221a to 221f. However, the DC-AC converter 220 is not limited to the configuration shown in the figure, and may be any configuration that can convert from direct current to alternating current.

Furthermore, the AC-DC converter 210 and the DC-AC converter 220 are electrically connected to the DC switch connection terminal 240 (terminal 241 and terminal 242). The DC switch connection terminal 240 is electrically connected to the DC power supply 600 through the DC switch 320. The DC power supply 600 is not limited to a specific configuration, and may be any one that can supply a DC voltage. Examples of the DC power supply 600 include storage batteries such as nickel metal hydride batteries and lithium ion batteries, solar batteries, and fuel cells.

Further, the inductive load 230 is, for example, an electric motor. When the inductive load 230 is an electric motor, the inductive load 230 includes a stator (stator) 231, a rotor (rotor) 232, and a load 233, and an alternating current from the DC-AC conversion unit 220. By generating a rotating magnetic field in the winding of the stator 231, the rotor 232 is rotated and the load 233 is driven. In addition, although the electric motor is illustrated here as the inductive load 230, it is not limited to this. As the inductive load 230, a coil for induction heating can be exemplified.

The AC-DC conversion unit 520 of the AC power supply 500 includes four switching elements 521a to 521d and a filter unit 522. The AC-DC converter 520 converts the direct current from the direct-current power supply 600 into alternating current having the same amplitude and the same frequency as the commercial power supply 510 by using the four switching elements 521a to 521d and the filter unit 522.

The AC-DC conversion unit 520 can also convert the alternating current of the alternating current power supply 500 into direct current by rectifying with a diode constituted by the four switching elements 521a to 521d.

The DC-DC converter 620 of the DC power supply 600 includes four switching elements 621a to 621d, a transformer 622, four switching elements 623a to 623d, and a smoothing capacitor 624. The DC-DC converter 620 converts the direct current of the direct current voltage source 610 into alternating current by controlling the open / closed states of the four switching elements 621a to 621d, and AC power is transferred from the primary side to the secondary side of the transformer 622. Communicated. The transmitted AC power is rectified by a diode constituted by four switching elements 623a to 623d, smoothed by a smoothing capacitor 624, and converted into a DC of a predetermined voltage.

Conversely, the DC-DC converter 620 converts the direct current supplied from the AC-DC converter 520 into an alternating current by controlling the open / closed states of the four switching elements 623 a to 623 d, so that the secondary of the transformer 622 is secondary. It is also possible to transmit AC power from the side to the primary side. The transmitted AC power is rectified by a diode constituted by four switching elements 621 a to 621 d and supplied to a DC voltage source 610. Thus, since the DC-DC converter 620 can be operated as a bidirectional type, when the DC voltage source 610 is a storage battery, for example, both the AC switch 310 and the DC switch 320 are opened. It is also possible to charge as a state.

Here, the DC-DC conversion unit 620 is not limited to the bidirectional type, and may be a step-up type, a step-down type, or a step-up / down type, and the DC-DC conversion unit 620 can adjust a DC voltage. If there is, it is not limited to a specific configuration.

Here, the operation of the inverter device 200 will be described. First, the case where inverter device 200 is operated using AC power supply 500 as a power source will be described by comparing the configuration of the comparative example with the configuration of the present embodiment (during normal operation).

FIG. 3A is a diagram for explaining a power supply path during normal operation in the configuration of the comparative example. During normal operation, AC power from the AC power supply 500 is supplied to the inverter device 200 via the AC switching unit 310 (thick arrow in FIG. 3A). The AC power supplied to the inverter device 200 is supplied to the inductive load 230 via the AC-DC converter 210 and the DC-AC converter 220. By following such a path, power loss occurs in the AC-DC converter 210 and the DC-AC converter 220.

FIG. 3-2 is a diagram for explaining a power supply path during normal operation in the configuration of the present embodiment. During normal operation, the AC switch 310 is closed and the DC switch 320 is open. At this time, the AC power of the AC power source 500 is supplied to the inverter device 200 via the AC switching unit 310 (thick arrow in FIG. 3-2). The AC power supplied to the inverter device 200 is supplied to the inductive load 230 via the AC-DC converter 210 and the DC-AC converter 220. By following such a path, power loss occurs in the AC-DC converter 210 and the DC-AC converter 220.

That is, the electric power from the AC power supply 500 follows the same path in both the configuration of the present embodiment and the configuration of the comparative example.

Next, the case where the supply of power from the commercial power supply 510 of the AC power supply 500 is stopped (power failure) will be described (emergency).

FIG. 4A is a diagram for explaining an emergency power supply path in the configuration of the comparative example. In an emergency, the DC power source 600 is used as a power source, and the AC-DC converter 520 converts the direct current into alternating current. At this time, power loss from the DC voltage source 610 occurs in the DC-DC converter 620, AC-DC converter 520, AC-DC converter 210, and DC-AC converter 220. There is a problem that power consumption is larger than time.

Therefore, in this embodiment, in the event of an emergency, the DC switching unit 320 is closed, and the DC-DC conversion unit 620 is electrically connected to the DC-AC conversion unit 220 via the DC switching unit 320. The location can be only the DC-DC converter 620 and the DC-AC converter 220. Thus, since power consumption can be suppressed, for example, when the DC voltage source 610 is a storage battery, it is possible to suppress a decrease in the remaining battery capacity and to drive the inverter device 200 for a long time. . Moreover, deterioration of the battery can also be suppressed.

FIG. 4-2 is a diagram for explaining an emergency power supply path in the configuration of the present embodiment. In an emergency, the AC switch 310 is opened and the DC switch 320 is closed. At this time, the DC power of the DC power supply 600 is supplied to the inverter device 200 via the DC switching unit 320 (solid thick arrow in FIG. 4-2). The AC power supplied to the inverter device 200 is supplied to the inductive load 230 via the DC-AC converter 220. By following such a path, power loss from the DC voltage source 610 occurs in the DC-DC converter 620 and the DC-AC converter 220. Compared with the configuration of the comparative example, the power loss The power consumption can be reduced. In addition, the path | route in the structure of a comparative example is shown with a dotted line.

As described above, according to the configuration of the present embodiment, power loss can be suppressed more than in the comparative example in an emergency.

When the DC voltage output from the DC-DC converter 620 is made higher than the DC voltage output from the AC-DC converter 210 and is supplied to the DC-AC converter 220, the DC voltage is supplied to the inductive load 230. The voltage can be increased, and the driving capability of the inductive load 230 can be increased.

In addition, when the inverter device 200 is operated only by the commercial power source 510 of the AC power source 500, the power consumption of the commercial power source 510 increases, and a breaker (not shown) of the switchboard may be cut off due to an increase in current. Further, when the power supply capacity of the commercial power supply 510 is reduced, when large power is consumed at the same time in the surrounding area, the demand power may exceed the supply power and cause a large-scale power outage or the like.

Therefore, in the inverter system having the configuration of the present embodiment, the DC power supply 600 may be operated as an auxiliary power supply even in an emergency. That is, power is supplied from both the AC power source 500 and the DC power source 600, the AC voltage of the AC power source 500 is supplied via the AC switching unit 310, and the DC voltage from the DC power source 600 is supplied via the DC switching unit 320. When the inductive load 230 is driven, the power consumed by the commercial power supply 510 is suppressed, and the above problem can be solved.

FIG. 5 is a diagram illustrating a power supply path when power is supplied from both the AC power supply 500 and the DC power supply 600 as described above. When power is supplied from both the AC power source 500 and the DC power source 600, both the AC switching unit 310 and the DC switching unit 320 are closed as shown in FIG.

Even if the power supply capability of the commercial power supply 510 is not reduced, the configuration of FIG. 5 drives the inverter device 200 with the maximum power of the AC power supply 500 and the DC power supply 600 and outputs the inductive load 230. It is possible to operate with an increased capability (such as the number of revolutions).

Even when the operation is performed as shown in FIG. 5, the power loss from the DC voltage source 610 can be kept low as in FIG.

As described above, according to the configuration of the present embodiment, it is possible to suppress the power loss of the DC power supply that operates as an auxiliary power supply even in an emergency.

In addition, as the AC switching unit 310 and the DC switching unit 320 provided in the switching unit 300 of the present embodiment, a general unit such as a relay or a contactor may be used. For example, the excitation coil is controlled by the switching control unit 400. The open / close state of the open / close unit 300 can be switched.

The opening / closing control unit 400 may be configured by, for example, a microcomputer. The open / close control unit 400 may be configured to be operated by, for example, an external input signal (current, voltage, temperature, etc.) or an external controller (not shown).

In addition, the opening / closing control unit 400 has a configuration that detects from the voltage value or the like that the supply of power from the AC power supply 500 has stopped due to a power failure or the like, and detects that the supply of power from the AC power supply 500 has stopped In this case, the above-described effect can be obtained by setting the AC switch 310 to the open state and the DC switch 320 to the closed state.

The AC power source 500 may be a generator or the like as long as AC power can be supplied, and is not limited to a specific configuration. Also, the DC power supply 600 may be a DC power supply outlet or the like as long as DC power can be supplied, and is not limited to a specific configuration. However, the power systems of the AC power supply 500 and the DC power supply 600 are different.

Further, the opening / closing unit 300 and the opening / closing control unit 400 may not be mounted in the same housing as the inverter device 200 as illustrated. The opening / closing unit 300 and the opening / closing control unit 400 may be mounted on, for example, a switchboard or distribution board, or may be mounted on the AC power supply 500 or the DC power supply 600.

Note that the four diodes 212a to 212d constituting the AC-DC conversion unit 210, the six switching elements 221a to 221f constituting the DC-AC conversion unit 220, and the four switching elements 521a to constituting the AC-DC conversion unit 520 are provided. 521d, the four switching elements 621a to 621d and the four switching elements 623a to 623d constituting the DC-DC converter 620 are formed of a wide gap semiconductor made of silicon carbide (SiC), gallium nitride (GaN), or diamond. May be.

Switching elements and diodes formed of such wide bandgap semiconductors have high voltage resistance and high allowable current density, so that the elements themselves can be miniaturized, and the semiconductor modules incorporating these elements can be miniaturized. It becomes possible.

Also, since the heat resistance is high, the heat sink fins can be downsized and the water cooling section can be air cooled, so that the semiconductor module can be further downsized.

Furthermore, since the power loss is low, the switching element and the diode can be made highly efficient, and the semiconductor module can be made highly efficient.

Alternatively, the same effect can be obtained by using a super junction structure MOSFET known as a highly efficient switching element.

Embodiment 2. FIG.
FIG. 6 is a diagram showing an inverter system according to the present embodiment. FIG. 6 shows a plurality of power switching inverter systems 100a (first unit), 100b (second unit), a power switching inverter non-equipment device 700, and an external controller 800. The plurality of power switching inverter systems The

devices

100a and 100b and the power supply switching inverter non-mounting device 700 are electrically connected to the AC power source 500 and the DC power source 600. The plurality of power supply

switching inverter systems

100a and 100b include

inverter devices

200a and 200b, opening and

closing units

300a and 300b, and opening and

closing control units

400a and 400b, respectively.

First, the case where the

inverter devices

200a and 200b are operated using the AC power source 500 as a power source in the configuration shown in FIG.

FIG. 7 is a diagram for explaining a power supply path during normal operation of the configuration shown in FIG. During normal operation, the

inverter devices

200a and 200b are electrically connected to the AC power source 500 with the

AC switching units

310a and 310b closed, and the

DC switching units

320a and 320b are opened and disconnected from the DC power source 600. The

AC power from the AC power supply 500 is supplied to the

inverter devices

200a and 200b via the

AC switching units

310a and 310b along a path indicated by an arrow in FIG. AC power is also supplied from AC power supply 500 to power supply switching inverter non-mounting apparatus 700.

Next, an emergency will be explained. FIG. 8 is a diagram for explaining an emergency power supply path having the configuration shown in FIG. In an emergency in which power is not supplied from the commercial power source 510, the

inverter devices

200a and 200b are disconnected from the AC power source 500 with the

AC switching units

310a and 310b open, and the

DC switching units

320a and 320b are closed. It is electrically connected to the DC power supply 600.

The electric power of the DC power supply 600 is supplied to the

inverter devices

200a and 200b through the DC-DC conversion unit 620 and the

DC switching units

320a and 320b along the path indicated by the arrow in FIG. In addition, power is supplied from the DC power supply 600 to the power supply switching inverter non-mounting apparatus 700 via the DC-DC conversion unit 620 and the AC-DC conversion unit 520.

As shown in FIG. 8, a DC voltage can be supplied to the

inverter devices

200a and 200b without stopping the operation of the power supply switching inverter non-equipment device 700 even in an emergency. In the configuration shown in FIG. 8 as well, the power loss can be suppressed as in Embodiment 1, and the power consumption of the DC power supplied from DC voltage source 610 can be suppressed. Thus, since power consumption can be suppressed, for example, when the DC voltage source 610 is a storage battery, it is possible to suppress a decrease in the remaining battery capacity and to perform long-time driving. In addition, it is possible to suppress deterioration of the battery.

Further, similarly to FIG. 5 of the first embodiment, both the AC power supply 500 and the DC power supply 600 can be used in the configuration of the present embodiment.

FIG. 9 is a diagram for explaining a power supply path when power is supplied from both the AC power supply 500 and the DC power supply 600.

In FIG. 9, when both of the

AC switching units

310a and 310b and the

DC switching units

320a and 320b are closed, power can be supplied from both the AC power source 500 and the DC power source 600. However, when the direct current of the direct current power source 600 is converted into alternating current by the AC-DC conversion unit 520, power is supplied from the

AC switching units

310a and 310b, and thus power loss by the AC-DC conversion unit 520 occurs. Therefore, when the operation of the switching elements 521a to 521d of the AC-DC converter 520 is stopped, power loss due to the AC-DC converter 520 can be suppressed.

In FIG. 9, since the

inverter devices

200a and 200b are supplied with power from both the AC power supply 500 and the DC power supply 600, as described in the first embodiment, the burden on the AC power supply 500 is suppressed, and the AC power supply 500 is reduced. It is possible to reduce the power demand for the commercial power supply 510 that constitutes a large-scale power outage due to power shortage.

In addition, the external controller 800 includes a configuration (not shown) that detects the power, voltage, and current status of the AC power supply 500, the DC power supply 600, the power supply

switching inverter systems

100a and 100b, and the power supply switching inverter non-equipment 700. If the amount of power used by the AC power source 500 is excessively large, one or both of the

AC switching units

310a and 310b may be opened to supply power only from the DC power source 600, even in an emergency. May be operated.

Conversely, when the amount of power used by the DC power source 600 is large, for example, when the remaining capacity of the storage battery constituting the DC voltage source 610 is small, one or both of the

DC switching units

320a and 320b are opened to open the AC power source. You may operate | move so that electric power may be supplied only from 500.

Furthermore, the

AC switching units

310a and 310b and the

DC switching units

320a and 320b may be opened, and the DC voltage source 610 may be charged via the AC-DC conversion unit 520 and the DC-DC conversion unit 620.

Although not shown, the

inverter devices

200a and 200b of the present embodiment may also be provided with a DC switching unit connection terminal that is electrically connected to the

DC switching units

320a and 320b.

As described above, the inverter systems described in the first and second embodiments can be applied to all inverter devices that convert an AC voltage into a DC voltage and then convert it again into an AC voltage having a different amplitude and frequency. Examples of general household use include air conditioners equipped with inverters, refrigerators, electromagnetic cookers, heat pump water heaters, ventilation and blower fans, and air conditioners and electromagnetics that consume particularly large amounts of power. It is particularly preferable to apply to a cooker.

When applied to an air conditioner, when the output voltage of the DC-DC converter 620 of the DC power supply 600 is increased and supplied, the operating frequency of the compressor motor, which is the inductive load 230 in the air conditioner, is increased. It is possible to obtain a cooling or heating effect in a short time.

Further, when the room temperature is stabilized, the operating frequency is lowered and a high direct current voltage is not required. Therefore, the voltage output from the DC-DC converter 620 is lowered to switch the switching elements 221a to 221a constituting the DC-AC converter 220. Since power loss due to switching of 221f can be reduced, power consumption can be reduced and energy can be saved.

In addition, when applied to an electromagnetic cooker such as an IH cooking heater, when the output voltage of the DC-DC conversion unit 620 of the DC power supply 600 is increased and supplied, a pot using a heating coil that is an inductive load in the electromagnetic cooker. As a result, the cooking time can be shortened.

In addition, since a high DC voltage is not required when keeping warm or cooking at a low temperature, if the voltage output from the DC-DC converter 620 is lowered, the switching element 221a constituting the DC-AC converter 220 is used. Since power loss due to switching of ˜221f can be suppressed, power consumption can be reduced to save energy.

100 power switching inverter system, 200, 200a, 200b inverter device, 210 AC-DC converter, 211 reactor, 212a-212d diode, 213 capacitor, 220 DC-AC converter, 221a-221f switching element, 230 inductive load, 231 stator, 232 rotor, 233 load, 240 DC switch connection terminal, 241, 242 terminal, 300 switch, 310 AC switch, 320 DC switch, 400 switch controller, 500 AC power supply, 510 commercial power supply, 520 AC-DC converter, 521a to 521d switching element, 522 filter, 600 DC power supply, 610 DC voltage source, 620 DC-DC converter, 621a to 621d switching element, 622 Lance, 623a ~ 623d switching element, 624 a smoothing capacitor, 700 the power switching inverter non-mounting device, 800 external controller.

Claims

An AC / DC converter that converts AC to DC and outputs the output;
A direct current to alternating current converter that converts direct current to alternating current and outputs the inductive load
An inverter device comprising: the AC / DC conversion unit and a DC switching unit connection terminal drawn from between the DC / AC conversion unit.
An inverter system comprising: an AC to DC converter that converts AC to DC and outputs; and a DC to AC converter that converts DC to AC and outputs it to an inductive load,
The AC / DC conversion unit is electrically connected to an AC power source via an AC switching unit controlled by the switching control unit,
The DC / AC conversion unit is electrically connected to a DC power source via a DC switching unit controlled by the switching control unit,
The AC / DC converter is a power supply switching inverter system electrically connected to the inductive load via the DC / AC converter.
When power is supplied from the AC power source,
The open / close control unit closes the AC open / close unit, sets the DC open / close unit to an open state, and supplies power from the AC power source to the AC / DC conversion unit,
When power is not supplied from the AC power source,
3. The power supply according to claim 2, wherein the open / close control unit supplies the electric power from the DC power source to the DC / AC conversion unit by setting the AC switch unit to an open state and the DC switch unit to a closed state. Switching inverter system.
The open / close control unit supplies power from the AC power source to the AC / DC conversion unit, and supplies power from the DC power source to the DC / AC conversion unit with both the AC switching unit and the DC switching unit closed. The power supply switching inverter system according to claim 2, wherein the power supplied to the inductive load is controlled so as not to exceed a limit value.
The power switching inverter system according to any one of claims 2 to 4, wherein the open / close control unit is operated by an external controller.
The power supply switching inverter system according to any one of claims 2 to 5, wherein the DC power supply is a storage battery or an electric vehicle equipped with a storage battery.
The power switching inverter system according to claim 6, wherein the switching control unit charges the storage battery with both the AC switching unit and the DC switching unit open.
The power supply switching inverter system according to any one of claims 2 to 7, wherein the AC / DC conversion unit and the semiconductor element constituting the DC / AC conversion unit are formed of a wide band gap semiconductor. .