JP2001186780A - Power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device using a plurality of sets of switch arms each composed of a unipolar transistor having a parasitic diode, and power storage means.

[0002]

2. Description of the Related Art FIG. 12 is a typical system configuration diagram of this type of power supply device.

In FIG. 12, 1 is a commercial power supply as an AC power supply, 2 is a power supply device, 3 is an AC filter on the side of the commercial power supply 1, 4 is a forward conversion circuit, 5 is a smoothing capacitor, 6 is an inverse conversion circuit, 7 is An AC filter on the output side of the inverse conversion circuit 6, 8 is a chopper circuit, 9 is a battery as power storage means, and 10 is a load of the power supply device 2.

In the power supply device 2, when the commercial power supply 1 is normal, the power is rectified by the forward conversion circuit 4 and
The DC voltage smoothed in step (1) is converted to an AC voltage substantially the same as that of the commercial power supply 1 by the inverse conversion circuit 6 and supplied to the load 10. Also, the battery 9 is charged from the output of the forward conversion circuit 4 via the chopper circuit 8. When the commercial power supply 1 is abnormal such as a power failure, the battery 9
Is supplied to the load 10 via the chopper circuit 8 and the inverse conversion circuit 7. That is, the power supply to the load 10 is called an uninterruptible power supply (UPS) because the AC power is supplied from the battery 9 to the load 10 without interruption even if the commercial power supply 1 is lost.

FIG. 13 shows that each of the semiconductor switch circuits forming a plurality of sets of switch arms provided in the power supply device 2 shown in FIG.
FIG. 3 is a detailed circuit configuration diagram in the case of using a BT. The forward conversion circuit and the inverse conversion circuit are each configured by one set of switch arms.

In FIG. 13, reference numeral 2a denotes a power supply as the power supply 2; 3a, an AC filter as the AC filter 3; 4a, a switch arm as the forward conversion circuit 4;
Is a smoothing capacitor as the smoothing capacitor 5, and this smoothing capacitor 5a is a capacitor 5a1 and a capacitor 5a2.
6a is a switch arm as an inverse conversion circuit 6, 7a is an AC filter as an AC filter 7, 8a
Is a switch arm that forms the chopper circuit 8, 8b is a DC reactor that forms the chopper circuit 8, and 8c is a smoothing capacitor that forms the chopper circuit 8.

That is, in the circuit configuration shown in FIG.
As is well known, the switch arm 4a and the smoothing capacitor 5a
Have a rectifying power supply function, and the switch arm 6a and the smoothing capacitor 5a have an inverter function.

FIG. 14 shows a system configuration diagram having a function different from that of the power supply device shown in FIG. 12. When the commercial power supply 1 is normal, the switch 200 is closed to supply power from the commercial power supply 1 to the load 10. In the order of the switch arm,
The reverse conversion circuit 60 is operated as a rectifier circuit, the rectified voltage is smoothed by the smoothing capacitor 50, and the battery 90 is charged via the chopper circuit 80 including a switch arm and the like.
When the commercial power supply 1 is in an abnormal state such as a power failure, the switch 200 is opened, and the power of the battery 90 is
A so-called standby type uninterruptible power supply (SPS) for supplying an AC voltage substantially equal to that in the normal state of the commercial power supply 1 to the load 10 via the forward / inverting circuit 60 and the AC filter 70 in the inverter operation. ).

FIG. 15 is a detailed circuit configuration diagram of each switch arm constituting FIGS. 13 and 14.
As an example, the circuit configuration of the switch arm 4a shown in FIG. 13 is shown, 4ap is a P-side semiconductor switch circuit, 4an is an N-side semiconductor switch circuit, 4ap1, 4
an1 is an IGBT, 4ap2, 4an2 are diodes,
4agp is a gate drive circuit of the IGBT 4ap1, 4ag
n is a gate drive circuit of IGPT4an1.

FIG. 16 shows typical ON characteristics of the switch arm 4ap shown in FIG.

As is apparent from FIG. 1, the on-state characteristic during forward flow shows a rising voltage Vot specific to a bipolar transistor, and this rising voltage Vot is equal to IGB.
One stage of the output transistor of T is about 1 volt, and that of the three-stage Darlington transistor is about 3 volts. Also,
At the time of reverse flow, the on-voltage characteristic of the diode, which is a bipolar element, is shown, and Vod is the rising voltage of this diode.

In this type of switch arm, the rising voltage of the IGBT and the diode is made as low as possible in order to reduce the loss during forward and reverse flow.

FIG. 17 is a detailed circuit configuration diagram using MOSFETs for the respective switch arms constituting FIGS. 13 and 14 described above.

In FIG. 17, 4b is a switch arm,
4 bp is a P-side semiconductor switch circuit, 4 bn is an N-side semiconductor switch circuit, 4 bp 1 and 4 bn 1 are MOSFEs.
T, 4bp2, 4bn2 are MOSFET4bp1, 4b
Parasitic diode built in each of n1, 4bgp, 4
bgn denotes a gate drive circuit of each of the MOSFETs 4bp1 and 4bn1, 4c denotes a gate power supply, and 4d denotes a control circuit.

FIG. 18 shows the MOSFET 4 shown in FIG.
FIG. 4 is a detailed circuit configuration diagram of a gate drive circuit of bp1 or 4bn1, 4x is a semiconductor switch circuit corresponding to the semiconductor switch circuit 4bp or 4bn, 4xg is a gate drive circuit corresponding to the gate drive circuit 4bgp or 4bgn, 4x
g1 denotes a gate drive power supply circuit that supplies gate drive power from the gate power supply 4c to the gate circuit 4xg3 via the insulating transformer 4xg2. The switching signal is sent from the control circuit 4d to the gate control circuit 4xg4 and the insulation transformer 4xg.
5 to the gate circuit 4xg3.

That is, the switch arm 4 shown in FIG.
b is configured by using two sets of the gate drive circuits shown in FIG.

FIG. 19 shows the ON characteristics of the semiconductor switch circuit shown in FIG. 17 in comparison with the ON characteristics shown in FIG. As is clear from this characteristic diagram, the ON characteristic during forward flow is a unipolar characteristic, while the ON characteristic during reverse flow is a diode characteristic, like the characteristic shown in FIG. This is because the parasitic diode characteristics of the MOSFET are the same as those of the diode shown in FIG.

[0018]

The major problems in realizing a power supply device using a semiconductor element are improvement in conversion efficiency, improvement in device performance, reduction in size and weight of the device, and reduction in cost.

FIG. 20 shows an example of the relationship between the magnitude of the load and the efficiency of an uninterruptible power supply as a power supply using bipolar transistors, and shows that the efficiency is greatly reduced when the load is reduced. ing. From the viewpoint of energy saving, it is a major issue to improve the efficiency of a semiconductor power converter such as an uninterruptible power supply at a light load.

As measures to improve the efficiency at light load, the following 1),
Item 2) is effective. 1) A semiconductor element having a unipolar characteristic is used in both directions. 2) The switching performance of the semiconductor device is increased to such an extent that the switching loss can be substantially ignored.

FIG. 21 shows voltage-current characteristics when an ideal semiconductor device satisfying the above items 1) and 2) is obtained. That is, the semiconductor element having the characteristics shown in FIG. 21 is a unipolar element when bidirectional current flows.

Using a semiconductor device having the characteristics shown in FIG.
FIG. 22 shows the efficiency characteristics in which the switching loss is reduced to zero, corresponding to the characteristics shown in FIG. 20, where the solid line is the semiconductor element shown in FIG. 21 and the broken line is the characteristic shown again in FIG.

As another major problem when a bipolar transistor is used for a switch arm of a power supply such as an uninterruptible power supply, the switching frequency cannot be increased. The greatest factor is that the bipolar transistor generates a storage carrier phenomenon peculiar to the bipolar element.

FIG. 23 shows the above-mentioned accumulated carrier phenomenon and FIG.
5 shows a relationship with the switching operation of the switch arm by the IGBT shown in FIG.

In FIG. 23, in the switching mode, the IGBT (4ap1) is turned off and the load current Io is reduced to IGB.
This is a mode in which commutation is performed from T (4ap1) to the diode (4an2), and the mode is a mode in which the load current Io continuously flows through the diode (4an2). The mode is a mode in which the IGBT (4ap1) is turned on and the load current Io is commutated from the diode (4an2) to the IGBT (4ap1).

At time T1, even if the gate of the IGBT (4ap1) is turned off, the IGBT does not turn off immediately, and a current flows for a certain time (Tstg shown). That is, at time T1
To turn off the IGBT (4ap1) and at the same time
When an1) is turned on, it means that arm short-circuiting (short circuit between PNs in the figure) occurs. For this reason, in the switch arm using the IGBT, a dead time (Td in the figure) is provided so that the IGBT (4an1) is not turned on for a specified time after the IGBT (4ap1) is turned off.

In the current switch arm using the IGBT, the dead time is about 1 μS.

The above-mentioned dead time greatly affects the upper limit of the switching frequency of the switch arm. FIG.
4 shows the relationship between the switching frequency based on the dead time and the output voltage of the uninterruptible power supply, and shows the case where the dead time is 1 μs. That is, it indicates that as the switching frequency increases, the output voltage decreases due to the dead time. In the current switch arm using the IGBT, the switching frequency is several tens of k.
Hz.

Next, in the case of the switch arm using the MOSFET shown in FIG.
9, the parasitic diode built into the MOSFET is designed to reduce the on-voltage as low as possible. However, from the characteristics of this parasitic diode,
The current switch arm using a MOSFET has a problem that the switching frequency cannot be increased.

Hereinafter, this problem will be described.

Generally, the operating frequency of a diode is limited by the reverse recovery characteristic of the diode.

FIGS. 25A and 25B are waveform diagrams for explaining the operation when the parasitic diode of the MOSFET is turned off (corresponding to the operation at the time T5 shown in FIG. 23). FIG. 25A shows the current waveform of the parasitic diode, and FIG. ) Is the voltage waveform of the parasitic diode,
(C) shows a loss waveform generated in the parasitic diode at the time of off.

That is, in the waveform of FIG. 25A, the current in the hatched portion is the reverse recovery current when the parasitic diode is off, and the loss that occurs at this time is the product of the current in FIG. Become. Therefore, the switching loss of the parasitic diode becomes twice the switching frequency of the integral value of the loss waveform in (c).

The parasitic diode of the current MOSFET is
As described above, the rising voltage is reduced as much as possible in order to reduce the loss of the power supply such as the uninterruptible power supply. As a result, the switching loss of the parasitic diode increases, and the switching frequency is limited to about several tens of kHz.

As described above, the current MOSFET is a unipolar type at the time of forward flow, and has a reverse flow characteristic of a bipolar characteristic despite its switching frequency of several hundred kHz. From the reverse recovery characteristic, the switching frequency is about 1/10 of that of the MOSFET.

An object of the present invention is to provide a power supply device having a high switching frequency and high conversion efficiency.

[0037]

According to the first aspect of the present invention, at least one set of switch arms constituting a forward conversion circuit is provided.
A switch arm forming one DC side of the chopper circuit and at least one set of switch arms forming an inverse conversion circuit are connected in parallel to each other, and power storage means is connected to the other DC side of the chopper circuit. A power supply device that normally supplies power to a load from an AC power supply via a forward conversion circuit and an inverse conversion circuit, and charges a power storage unit via the forward conversion circuit and a chopper circuit. When the AC power supply is abnormal, in a power supply device for supplying power to the load from the power storage means via a chopper circuit and an inverse conversion circuit, each semiconductor switch circuit forming each of the switch arms may be a unipolar having a parasitic diode. And a specified current flowing through the unipolar transistor when the unipolar transistor is turned on. The ON voltage is set to be equal to or higher than the ON voltage generated when the current flows.

According to a second aspect of the present invention, a switch arm forming one DC side of the chopper circuit and at least one set of switch arms forming a forward / inverting conversion circuit are connected in parallel to each other, and the other of the chopper circuit is provided. A power supply device having a power storage means connected to the DC side. Normally, power is supplied from the AC power supply to the load, and the power storage means is supplied from the AC power supply through a forward / inverse conversion circuit and a chopper circuit. A power supply device that supplies power to the load via the chopper circuit and the forward / inverting conversion circuit from the power storage means when the AC power supply is abnormal. Is constituted by a unipolar transistor having a parasitic diode, and a rising voltage of the parasitic diode is set to an on state of the unipolar transistor. The on-state voltage is set to be equal to or higher than the on-voltage generated when a specified current flows in the state.

According to a third aspect of the present invention, at least one set of switch arms forming a forward conversion circuit, one set of switch arms forming one DC side of a chopper circuit, and at least one set of switch arms forming a reverse conversion circuit are provided. Are connected in parallel to each other, and a power storage means is connected to the other DC side of the chopper circuit. Normally, the power supply device is connected to a load from an AC power supply via a forward conversion circuit and an inverse conversion circuit. A power supply for supplying power to the load via the forward conversion circuit and the chopper circuit and charging the power storage means via the chopper circuit, and when the AC power supply is abnormal, supplying power from the power storage means to the load via the chopper circuit and the inverse conversion circuit; In the device, the switch arm is formed by a complementary connection of a unipolar transistor having a parasitic diode, and the switch arm of each of the parasitic diodes is provided. The gully voltage, and wherein the set than on-voltage generated when the flowed corresponding through the specified current at on state of the unipolar transistor.

According to a fourth aspect of the present invention, a switch arm forming one DC side of the chopper circuit and at least one set of switch arms forming a forward / inverting conversion circuit are connected in parallel to each other, and the other of the chopper circuit is provided. A power supply device having a power storage means connected to the DC side. Normally, power is supplied from the AC power supply to the load, and the power storage means is supplied from the AC power supply through a forward / inverse conversion circuit and a chopper circuit. A power supply device that supplies power to the load via the chopper circuit and the forward / inverting conversion circuit from the power storage means when the AC power supply is abnormal, wherein the switch arm is a unipolar transistor complementary diode having a parasitic diode. Connection, the rising voltage of each of the parasitic diodes is adjusted to a specified current when the corresponding unipolar transistor is turned on. The ON voltage is set to be equal to or higher than the ON voltage generated when current flows.

According to a fifth aspect, in the power supply device according to the first or second aspect, the unipolar transistor is an MO.
It is characterized in that it is an SFET.

According to a sixth aspect of the present invention, in the power supply device according to the third or fourth aspect, one of the unipolar transistors is an N-channel MOSFET and the other is a P-channel MOSFET.

According to a seventh aspect of the present invention, in the power supply device according to the first to sixth aspects, the specified current is a maximum output current of the power supply device.

According to an eighth invention, in the power supply device of the first to sixth inventions, the specified current is an absolute maximum rating of a unipolar transistor.

The present invention has been made by focusing on the following items 1) and 2). 1) Due to the element structure, the MOSFET is a unipolar element capable of bidirectional flow. 2) When the speed of the bipolar diode is increased, the rising voltage increases.

That is, a MOSFET in which the rising voltage of a parasitic diode included in the MOSFET is set to be equal to or higher than the ON voltage when a specified current of the MOSFET flows, and the switching frequency of the parasitic diode is approximately equal to the switching frequency of the MOSFET. As a switch arm, which enables high conversion efficiency and high-speed operation as described later.

[0047]

FIG. 1 is a circuit configuration diagram of a power supply device according to a first embodiment of the present invention, which corresponds to the circuit configuration of the conventional example shown in FIG.

In FIG. 1, 40ap, 40an, 60
ap, 60an, 80ap, 80an are semiconductor switch circuits, 40ap1, 40an1, 60ap1, 60an
1,80ap1,80an1 are MOSFET, 40ap
2,40an2,60ap2,60an2,80ap
Reference numeral 2, 80an2 denotes a parasitic diode of each of the MOSFETs.

FIG. 2 shows the semiconductor switch circuits 40ap, 40an, 60ap, 60an, 80ap,
Voltage at forward flow and reverse flow at 80an
This shows the current characteristics. This diagram is a device current-voltage characteristic diagram of a MOSFET which is a unipolar device when the gate is turned on. The operating range (indicated by the magnitude of the current value) is represented by If in the forward direction and Ir in the reverse direction.

That is, in the MOSFET as the unipolar transistor of the present invention, as shown in FIG. 2, the rising voltage Vo of the parasitic diode is set higher than the voltage Vt generated in the MOSFET.

The unipolar transistor in the circuit configuration shown in FIG. 1 can be constituted by an N-channel MOSFET having the characteristics shown in FIG.

FIG. 3 is a structural example of an N-channel MOSFET for realizing the characteristics shown in FIG.
d is a parasitic diode part built in the MOSFET, 40
nt is the MOSFET section, and the operating frequency of the parasitic diode 40nd is made to have almost the same frequency performance as the MOSFET section 40nt. For this purpose, lifetime control is performed by the same method as that used in conventional diode devices for increasing the frequency, for example, by doping platinum or the like which is a lifetime killer, or by irradiating an electron beam.

FIG. 4 is a circuit diagram showing a power supply device according to a second embodiment of the present invention.
n, 61an and 81an have circuit configurations corresponding to the semiconductor switch circuits 40an, 60an and 80an shown in FIG. 1, respectively. In the example of FIG.
The case of T is shown.

That is, in FIG. 4, the semiconductor switch circuits 40ap, 60ap, and 80ap are formed by N-channel MOSFETs as in the circuit configuration of FIG. 1, and the semiconductor switch circuits 41an formed by these N-channel MOSFETs and P-channel MOSFETs , 61an, 6
As shown in the figure, each of them has a complementary connection configuration.

FIG. 5 is a structural example of a P-channel MOSFET for realizing the characteristics of the present invention.
Is a parasitic diode part built in the MOSFET, 40p
t is a MOSFET section. This parasitic diode 40p
The operating frequency of d is set to be almost the same frequency performance as that of the MOSFET unit 40pt. For this purpose, lifetime control is performed by the same method as that used in conventional diode devices for increasing the frequency, for example, by doping platinum or the like which is a lifetime killer, or by irradiating an electron beam.

FIG. 6 shows the switching operation of the switch arm using the unipolar transistor shown in FIGS. 1 and 4, corresponding to the operation of the conventional example shown in FIG.

That is, in the switch arm of the present invention, the unipolar operation without the above-mentioned accumulated carrier time is obtained even in the forward and reverse flow, so that the switching operation without considering the dead time is enabled.

FIG. 7 is a detailed circuit configuration diagram of the switch arm shown in FIG. 4, and has a circuit configuration corresponding to the conventional switch arm shown in FIG.

In FIG. 7, reference numeral 41x denotes a switch arm, which is composed of a series circuit of a P-side semiconductor switch circuit 41xp and an N-side semiconductor switch circuit 41xn, as in the configuration of FIG. That is, 41xp1 which is an N-channel MOSFET and 41xn1 which is a P-channel MOSFET are complementarily connected. 41xg is 41xp1, 41xn
1, a gate drive circuit 41xg1, a gate drive power supply circuit 41xg2, a transformer 41xg3 a gate circuit 4,
1xg4 is a gate control circuit, 41xg5 is a transformer, 41
e is a gate power supply and 41f is a control circuit.

FIG. 8 is a circuit diagram of a power supply unit according to a third embodiment of the present invention, which is an example of application to the power supply unit shown in FIG.

In FIG. 8, the chopper circuit 80b is
Is the same as the circuit configuration shown in FIG.
b functions as a forward / inverse conversion circuit. When the commercial power supply 1 is normal, the switch arm 60b and the smoothing capacitor 50b operate as a rectifier circuit. When the commercial power supply 1 is abnormal, the inverter is connected to the smoothing capacitor 50b and the switch arm 60b. Work.

FIG. 9 is a circuit diagram of a power supply unit according to a fourth embodiment of the present invention. As shown in FIG.
This is an application example to the power supply device shown in FIG.

That is, the difference from FIG. 8 is that the circuit configuration shown in FIG. 7 is used as the switch arm.
Therefore, the chopper circuit 80c has the same circuit configuration as that shown in FIG. 4, but the switch arm 60c functions as a forward / inverse conversion circuit, and when the commercial power supply 1 is normal, the switch arm 6c
0c and the smoothing capacitor 50c perform a rectifying circuit operation, and when the commercial power supply 1 is abnormal, the smoothing capacitor 50c and the switch arm 60c perform an inverter operation.

The supplementary explanation of the operation of the unipolar transistor of the present invention at the time of reverse flow will be described below.

That is, when the current Ir flows in the reverse direction in the waveform diagram shown in FIG. 2, a slight current (indicated by Io in FIG. 2) flows through the parasitic diode. Since the parasitic diode is a bipolar element, even a small amount of current generates accumulated carriers.

However, in the unipolar transistor of the power supply device according to the present invention, since the speed of the parasitic diode portion is increased, a large reverse recovery current as in the prior art does not flow.

FIG. 10 shows a reverse recovery characteristic diagram (thick solid line) of the parasitic diode of the above-mentioned unipolar transistor, corresponding to the conventional characteristic shown in FIG. The thin line represents the characteristic shown in FIG. 25 again, and it can be seen from this characteristic that the switching loss is greatly reduced.

Although the above embodiments have been described with the circuit configuration having the smallest number of switch arms, the forward conversion circuit or the inverse conversion circuit or the forward / inverse conversion circuit is connected to a single-phase or three-phase bridge. The present invention can also be applied to a power supply device having the configuration described above.

[0069]

According to the present invention, the unipolar characteristic is obtained both in the forward direction and the reverse direction, so that the generation loss of the semiconductor element can be greatly reduced.

FIG. 11 is a diagram for explaining the effect.
(A) shows the current waveform of a unipolar transistor, which is a sinusoidal current in both directions, and (b) shows the voltage waveform of the transistor.
T and the thick line show the case of the MOSFET used in the present invention, and (c) shows the loss that occurs. The thin line shows the IGBT,
The thick line indicates the case of the MOSFET, and the shaded portion indicates the loss portion improved by the present invention in (c). According to the present invention, when a unipolar transistor is used for both bidirectional conduction, the generated loss is greatly reduced. It indicates that.

Further, according to the present invention, the rising voltage of the parasitic diode is greatly increased as compared with the prior art, and the MOSFE
Since it is made possible to operate at the same switching frequency as T, the inverter frequency can be greatly increased.
1 is closer to the ideal characteristic shown in FIG.

Further, according to the present invention, since the switch arms are configured in a complementary connection and the source potentials of both semiconductor switch circuits are made common, the gate drive power supply and control power supply of the semiconductor switch circuits are commonly used. As a result, it is possible to reduce the size, weight, and cost of a power supply such as an uninterruptible power supply.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a power supply device according to a first embodiment of the present invention;

FIG. 2 is a waveform chart illustrating the operation of FIG.

FIG. 3 is a structural example diagram of the unipolar transistor of FIG. 1;

FIG. 4 is a circuit configuration diagram of a power supply device according to a second embodiment of the present invention;

FIG. 5 is a structural example diagram of the unipolar transistor of FIG. 4;

FIG. 6 is a waveform chart illustrating the switch operation of FIG. 1;

FIG. 7 is a detailed circuit configuration diagram of the switch arm of FIG. 1;

FIG. 8 is a circuit configuration diagram of a power supply device according to a third embodiment of the present invention.

FIG. 9 is a circuit configuration diagram of a power supply device according to a fourth embodiment of the present invention.

FIG. 10 is a characteristic diagram of a parasitic diode of a unipolar transistor according to the present invention.

FIG. 11 is a diagram illustrating an effect of the present invention.

FIG. 12 is a typical system configuration diagram of a power supply device.

FIG. 13 is a circuit configuration diagram of a conventional power supply device using an IGBT.

FIG. 14 is a system configuration diagram of a power supply device, which is different from FIG.

FIG. 15 is a circuit configuration diagram of a conventional switch arm using an IGBT.

FIG. 16 is a diagram illustrating characteristics of the semiconductor switch circuit of FIG. 15;

FIG. 17 is a circuit configuration diagram of a conventional switch arm using a MOSFET.

FIG. 18 is a detailed explanatory diagram of the semiconductor switch circuit of FIG. 17;

FIG. 19 is a diagram illustrating characteristics of the semiconductor switch circuit in FIG. 17;

20 illustrates efficiency characteristics of the circuit illustrated in FIG. 15;

FIG. 21 is a diagram illustrating characteristics of an ideal unipolar element.

FIG. 22 is a diagram for explaining efficiency characteristics when an element having the characteristics shown in FIG. 21 is used.

FIG. 23 is a diagram illustrating the switch operation of FIG.

FIG. 24 is a diagram illustrating the switch characteristics of FIG.

FIG. 25 is a diagram illustrating characteristics of a conventional diode.

[Explanation of symbols]

1: commercial power supply, 2, 2a, 20, 20a, 20b, 20
c, 21: power supply device, 3, 3a, 30a: AC filter, 4, 41a: forward conversion circuit, 5, 5a, 5a1, 5a
2,8c, 50,50a, 50b, 50c ... smoothing capacitor, 6,6a, 60,61a ... inverting circuit, 60b,
60c: forward and reverse conversion circuit, 7, 7a, 70, 70a, 7
0b, 70c: AC filter, 8, 80, 82b, 82
c: chopper circuit, 9, 90, 90b, 90c: battery,
10 Load, 4a, 4b, 6a, 8a, 40a, 41
a, 41x, 60a, 61a, 60b, 60c, 80
a, 81a: Switch arm, 4ap, 4an, 4b
p, 4bn, 4x, 40ap, 40an, 41an, 4
1xp, 41xn, 60ap, 60an, 61an, 8
0ap, 80an, 81an ... Semiconductor switch circuit, 4
ap1,4an1 ... IGBT, 4ap2,4an2 ... diode, 4bp1,4bn1,4x1,40nt, 4
0pt, 40ap1, 40an1, 40xp1, 41a
n1,41xp1,41xn1,60ap1,60an
1,61an1,80ap1,80an1,81an1
... MOSFET, 4bp2, 4bn2, 4x2, 40n
d, 40pd, 40ap2, 40an2, 40xn2
41an2, 60ap2, 60an2, 61an2, 8
0ap2, 80an2, 81an2 ... parasitic diode,
8b, 80b DC reactor, 200, 200b, 2
00c: switch, 4c, 41e: gate power supply, 4d, 4
1f: control circuit, 4xg, 4bgp, 4bgn, 41x
g, 4agp, 4agn gate drive circuit, 4xg1,
41xg1 gate power supply circuit, 4xg2, 4xg5, 4
1xg2, 41xg5 ... transformer, 4xg4, 41xg4
... gate control circuit, 4xg3, 41xg3 ... gate circuit.

Claims (8)

[Claims] At least one set of switch arms forming a forward conversion circuit, at least one set of switch arms forming one DC side of a chopper circuit, and at least one set of switch arms forming an inverse conversion circuit are connected in parallel with each other. A power supply device in which power storage means is connected to the other DC side of the chopper circuit, and normally supplies power to a load from an AC power supply via a forward conversion circuit and an inverse conversion circuit, A power supply device that charges power storage means via the forward conversion circuit and the chopper circuit, and supplies power to the load from the power storage means via the chopper circuit and the inverse conversion circuit when the AC power supply is abnormal. Each semiconductor switch circuit forming each switch arm is constituted by a unipolar transistor having a parasitic diode; The rising voltage, the power supply device being characterized in that set in the ON voltage than that generated when the flowed a specified current in the on-state of the unipolar transistor. 2. A switch arm forming one DC side of a chopper circuit and at least one set of switch arms forming a forward / inverting conversion circuit are connected in parallel with each other, and the other DC side of the chopper circuit is connected to the other DC side. A power supply device to which the power storage means is connected. Normally, the power storage means is supplied with power from the AC power supply to the load, and charges the power storage means from the AC power supply via the forward / inverse conversion circuit and the chopper circuit. When the AC power supply is abnormal, in a power supply device for supplying power to the load from the power storage means via a chopper circuit and a forward / inverting conversion circuit, each of the semiconductor switch circuits forming each of the switch arms includes a parasitic diode. And a rising voltage of the parasitic diode is regulated by a specified voltage when the unipolar transistor is in an on state. A power supply device characterized in that the power supply device is set to a voltage higher than an on-voltage generated when current flows. 3. At least one set of switch arms forming a forward conversion circuit, one switch arm forming one DC side of a chopper circuit, and at least one set of switch arms forming an inverse conversion circuit are connected in parallel with each other. A power supply device in which power storage means is connected to the other DC side of the chopper circuit, and normally supplies power to a load from an AC power supply via a forward conversion circuit and an inverse conversion circuit, A power supply device that charges power storage means via the forward conversion circuit and the chopper circuit, and supplies power to the load from the power storage means via the chopper circuit and the inverse conversion circuit when the AC power supply is abnormal. A switch arm formed by a complementary connection of a unipolar transistor having a parasitic diode, and a rising voltage of each of the parasitic diodes; , Power and wherein the set than on-voltage generated when the flowed through the specified current in the on state of the corresponding unipolar transistors. 4. A switch arm forming one DC side of a chopper circuit and at least one set of switch arms forming a forward / inverting conversion circuit are connected in parallel with each other, and the other DC side of the chopper circuit is connected to the other DC side. A power supply device to which the power storage means is connected. Normally, the power storage means is supplied with power from the AC power supply to the load, and charges the power storage means from the AC power supply via the forward / inverse conversion circuit and the chopper circuit. When the AC power supply is abnormal, in a power supply device for supplying power to the load from the power storage means via a chopper circuit and a forward / inverting conversion circuit, the switch arm is formed by a complementary connection of a unipolar transistor having a parasitic diode. The rising voltage of each of the parasitic diodes passed a specified current in the ON state of the corresponding unipolar transistor. A power supply device characterized in that the power supply device is set to a voltage higher than an on-state voltage that sometimes occurs. 5. The power supply device according to claim 1, wherein the unipolar transistor is a MOSFET. 6. The power supply device according to claim 3, wherein one of said unipolar transistors is an N-channel MO.
A power supply device comprising an SFET and the other being a P-channel MOSFET. 7. The power supply device according to claim 1, wherein the specified current is a maximum output current of the power supply device. 8. The power supply device according to claim 1, wherein the specified current is an absolute maximum rating of a unipolar transistor.