TW201340577A - Power supply device and control method thereof - Google Patents

Abstract

To provide a compact and inexpensive power supply device with a current-fed full bridge inverter. A power supply device 10 is connected between DC power supplies V1, V2 to exchange power. The power supply device 10 advances a turnoff timing of a first upper arm switching element S1 of the current-fed full bridge inverter ahead of a turnoff timing of a second lower arm switching element S4 of the other switching leg to provide a shorter on time. The power supply device 10 further advances a turnoff timing of a second upper arm switching element S3 ahead of a turnoff timing of a first lower arm switching element S2 of the other switching leg to provide a shorter on time. The power supply device 10 can thus control on/off states of the first upper arm switching element S1 and the second upper arm switching element S3 via a single pulse transformer PT1.

Description

Power supply device and control method of power supply device

The present invention relates to a power supply device and a power supply device control method for supplying electric power of a DC power source to a load or the like.

In recent years, with the increasing awareness of global environmental protection, in addition to the urgent need for electric power, the importance of systems equipped with DC power supplies such as batteries, solar cells, and fuel cells is increasing. In such systems, there is a case where a power supply device that supplies electric power to a load by a DC power source is provided, and a battery is connected to the battery as a load to charge the battery.

Non-Patent Document 1 discloses a power supply device that can connect a current-shaped full-bridge inverter circuit and a voltage-shaped full-bridge inverter circuit by a transformer, thereby supplying electric power in both directions.

[Previous Technical Literature] [Non-patent literature]

(Non-Patent Document 1) K. Wang, CY Lin, L. Zhu, D. Qu, FC Lee and JS Lai, "Bi-directional DC to DC Converters for Fuel Cell Systems", IEEE power electronics in transportation, 22-23 Oct 1998, pp.47-51

In general, in the full-bridge inverter circuit, in order to operate the ON/OFF state of the upper arm switching element, it is necessary to generate a drive pulse insulated by a control means of the power supply device and supply it to the upper arm switching element. In the conventional power supply device described in Non-Patent Document 1, when a DC power source connected to a current-mode inverter is supplied with electric power to a DC load connected to a voltage-type inverter, a current-shaped inverter is formed. The ON/OFF state of the upper arm switching element of one of the legs of the bridge and the ON/OFF state of the lower arm switching element of the other leg are formed in the same manner. Therefore, in order to operate the ON/OFF states of the two upper arm switching elements of the bridge constituting the galvanostat, the control means must separately generate drive pulses that are insulated. Therefore, it is necessary to have the same number of optocouplers or pulse transformers as the switching elements, which is a factor that hinders the miniaturization or cost reduction of the power supply device.

Accordingly, an object of the present invention is to provide a power supply device having a full bridge type inverter which is low in cost and can be downsized.

In order to solve the above problems, the object of the present invention is as follows.

In the invention according to claim 1 of the present invention, the power supply device includes: a first switching circuit in which a smoothing inductor and a first smoothing capacitor are connected in series between the first DC terminals; And a control means for controlling an ON/OFF state of the switching element provided in the first switching circuit, wherein the power supply device is characterized in that: the first DC terminal of the first switching circuit is further connected in parallel: 1 upper arm switching element a first switching pin connected in series with the first lower arm switching element; and a second switching pin connecting the second upper arm switching element and the second lower arm switching element in series, and the first upper arm switching element The series connection point of the first lower arm switching element and the series connection point of the second upper arm switching element and the second lower arm switching element are between the first alternating current terminals, and an alternating current load is connected between the first alternating current terminals In the case where the ON state of the first upper arm switching element and the second lower arm switching element and the OFF state of the second upper arm switching element are maintained, the control means performs the step of closing the first lower arm switching element. 1 switching processing.

Other means are described in the form for carrying out the invention.

According to the present invention, it is possible to reduce the cost and size of a power supply device including a full bridge type inverter.

The form for carrying out the invention will be described in detail below with reference to the drawings.

(Configuration of the first embodiment)

Fig. 1 is a schematic block diagram showing a power supply device according to a first embodiment.

The power supply device 10 is connected between the DC power source V1 to which the DC load 14 is connected and the DC power source V2 to which the DC load 16 is connected. Power is supplied between the streaming power source V1 and the DC power source V2.

The power supply device 10 according to the first embodiment is switchable between a process of supplying power to the DC power source V2 and the DC load 16 by the DC power source V1, and a process of supplying power to the DC power source V1 and the DC load 14 by the DC power source V2.

For example, the DC power source V2 is a battery (12V), and the DC load 16 is a portable terminal that is directly driven by 12V DC of the battery. The DC load 14 is a computer, and the DC power source V1 is an AC adapter connected to a commercial power source.

The power supply device 10 of the first embodiment is switchable between an operation of supplying power to a battery (DC power supply V2) and a portable terminal (DC load 16) by an AC adapter (DC power supply V1) connected to a commercial power supply, And the operation of supplying electric power to the computer (DC load 14) by the battery (DC power supply V2) is performed.

The power supply device 10 includes: switching circuits 11 and 15; a voltage clamping circuit 12; switching elements S0 to S4 provided in the circuits; and a control means 20 for controlling ON/OFF states of the switching elements H1 to H4; and a pulse transformer PT1. (first pulse transformer); pulse transformer PT2 (second pulse transformer); pulse transformer PT3 (third pulse transformer); and optical coupler 13.

(Configuration of Switching Circuit 11)

A smooth inductor is connected in series between the DC terminals of the switching circuit 11, that is, between the node Nd5 and the node Nd6 (between the first DC terminals) L1 and smoothing capacitor C1 (first smoothing capacitor). A DC power supply V1 (first DC power supply) and a DC load 14 are connected in parallel to the smoothing capacitor C1.

The switching circuit 11 includes switching elements S1 to S4 and diodes DS1 to DS4. The switching elements S1 to S4 are connected in a full bridge manner. The switching elements S1 to S4 are connected in parallel with the diodes DS1 to DS4.

The switching circuit 11 includes a first switching pin in which a switching element S1 (first upper arm switching element) and a switching element S2 (first lower arm switching element) are connected in series to a node Nd1; and a switching element is connected in series to the node Nd2. The second switching pin of S3 (second upper arm switching element) and switching element S4 (second lower arm switching element). The first switching pin and the second switching pin are connected in parallel between the DC terminal of the switching circuit 11, that is, between the node Nd5 and the node Nd6.

The switching circuit 11 sets the node Nd1, which is a series connection point of the switching element S1 and the switching element S2, and the node Nd2, which is a series connection point of the switching element S3 and the switching element S4, as the alternating current terminal of the switching circuit 11 (first Between AC terminals).

A winding N1 is connected between the AC terminals of the switching circuit 11 (first switching circuit), that is, between the node Nd1 and the node Nd2 (between the first AC terminals).

The switching circuit 11 supplies electric power to a winding N1 (an alternating current load and a primary winding) connected between the node Nd1 and the node Nd2 (between the first alternating current terminals) by a direct current power supply V1 connected in parallel with the smoothing capacitor C1.

(Configuration of Voltage Clamp Circuit 12)

The voltage clamping circuit 12 connects the clamp switching element S0 and the clamp capacitor Cc in series. The switching element S0 is connected to the diode DS0 in anti-parallel. The voltage clamp circuit 12 is connected between the DC terminals of the switching circuit 11, and suppresses a surge voltage between the DC terminals.

(Configuration of Switching Circuit 15)

A smoothing capacitor C2 (second smoothing capacitor) is connected between the DC terminals of the switching circuit 15, that is, between the node Nd7 and the node Nd8 (between the second DC terminals). A DC power supply V2 (second DC power supply) and a DC load 16 are connected in parallel to the smoothing capacitor C2.

As described above, the switching circuit 15 includes switching elements H1 to H4 and diodes DH1 to DH4. The switching elements H1 to H4 are connected in a full bridge. The switching elements H1 to H4 are connected in parallel with the diodes DH1 to DH4.

The switching circuit 15 includes a third switching pin that connects the switching element H1 (third upper arm switching element) and the switching element H2 (third lower arm switching element) in series; and a switching element H3 (fourth upper arm switching element) The fourth switching pin connected in series with the switching element H4 (fourth lower arm switching element). The third switching pin and the fourth switching pin are connected in parallel between the node Nd7 of the switching circuit 15 and the node Nd8 (between the second DC terminals).

The switching circuit 15 is a series connection of the switching element H1 and the switching element H2 The connection point, that is, the node Nd3, and the node Nd4, which is a series connection point of the switching element H3 and the switching element H4, is set between the alternating current terminals (between the second alternating current terminals) of the switching circuit 15.

A resonance capacitor Cr, a resonance inductor Lr, and a winding N2 are connected in series between the node Nd3 of the switching circuit 15 and the node Nd4 (between the second AC terminals). Transformer T1 (main transformer) magnetically couples winding N1 (AC load and primary winding) to winding N2 (secondary winding).

The switching circuit 15 (second switching circuit) supplies electric power input from the winding N2 connected between the node Nd3 and the node Nd4 (between the second alternating current terminals) connected to the switching circuit 15 to the node Nd7 connected to the switching circuit 15 and DC load 16 between nodes Nd8 (between the second DC terminals).

As described above, in the power supply device 10 of the first embodiment, the current-mode full-bridge inverter, in which the voltage clamp circuit 12 is connected, is the switching circuit 11 and the smoothing inductor L1, and the voltage-shaped full-bridge type. The inverter is a configuration in which the switching circuit 15 and the smoothing capacitor C2 are connected.

The switching circuit 11 is connected to the voltage clamp circuit 12 composed of the switching element S0 and the clamp capacitor Cc, and the smoothing inductor L1, and is composed of the switching elements S1 to S4.

The switching circuit 15 is composed of switching elements H1 to H4.

The control means 20 controls the ON/OFF states of the switching elements S0 to S4 and the switching elements H1 to H4 through insulating means such as the optical coupler 13 or the pulse transformers PT1 to PT3. The control means 20 is transmitted through the optical coupler 13 It is connected to the clamp switching element S0 of the voltage clamp circuit 12. Further, the control means 20 is connected to the switching elements S1, S3 of the switching circuit 11 via the pulse transformer PT1. Further, the control means 20 is connected to the switching elements S2, S4 via an insulating means such as an optical coupler (not shown).

Further, the control means 20 is connected to the switching elements H1, H2 of the third switching pin of the switching circuit 15 via the pulse transformer PT2. The control means 20 is connected to the switching elements H3 and H4 of the fourth switching pin via the pulse transformer PT3. That is, in the present embodiment, the control means 20, the switching circuit 11, and the switching circuit 15 are electrically insulated. However, the present invention is not limited thereto, and the control means 20, the switching circuit 11, and the switching circuit 15 may not be electrically insulated.

2(a) to 2(c) are schematic diagrams showing the configuration of the pulse transformer in the first embodiment.

Fig. 2(a) is a schematic configuration diagram showing the pulse transformer PT1.

The pulse transformer PT1 has a primary drive winding 30, secondary drive windings 31 and 32, and a magnetic core 33. The primary drive winding 30 and the secondary drive windings 31, 32 are magnetically coupled by the magnetic core 33. The primary drive winding 30 is connected to the control means 20, and a voltage for outputting a signal is applied between the two ends. The secondary drive windings 31, 32 are connected to the control terminals of the switching elements S1, S3, respectively.

Fig. 2(b) is a diagram showing an example of the output signal of the secondary drive winding 31 of the pulse transformer PT1. The output signal of the secondary drive winding 31 is output to the control terminal of the switching element S1.

Figure 2 (c) shows the secondary drive winding 32 of the pulse transformer PT1 An example of the output signal. The output signal of the secondary drive winding 32 is output to the control terminal of the switching element S3. 2(b) and 2(c), the horizontal axis represents time t, and the vertical axis represents output signals. The output signal is, for example, the H-bit is +5V on time, and the L-bit is -5V on time.

When the output signal of the secondary drive winding 31 shown in Fig. 2(b) is output at the H level, the output signal of the secondary drive winding 32 shown in Fig. 2(c) is the output L level. When the output signal of the secondary drive winding 31 is output at the L level, the output signal of the secondary drive winding 32 outputs the H level. That is, the output signal of the secondary drive winding 31 and the output signal of the secondary drive winding 32 complement the H level and the L level complementarily. That is, the output signal of the secondary drive winding 31 (the first secondary drive winding) and the output signal of the secondary drive winding 32 (the second secondary drive winding) are complementary drive pulses.

Thereby, the pulse transformer PT1 outputs a signal that is ON/OFF in a complementary manner to the switching element S1 and the switching element S3.

The control means 20 applies a voltage to the primary drive winding 30, generates a voltage in the secondary drive windings 31, 32, and supplies complementary drive pulses to the switching elements S1, S3 connected to the secondary drive windings 31, 32, and switches the components. S1 and S3 are ON/OFF complementarily.

Similarly, the pulse transformer PT2 magnetically couples one primary drive winding, the third secondary drive winding, and the fourth secondary drive winding. The output signal of the third secondary drive winding is an ON/OFF state of the operation switching element H1 (third upper arm switching element). The output signal of the fourth secondary drive winding is operated by the switching element H2 (third lower arm switching element) ON/OFF status. At this time, the output signals of the third secondary drive winding and the output signals of the fourth secondary drive winding are complementary drive pulses, and the switching elements H1 and H2 are complementarily turned ON/OFF.

Similarly, the pulse transformer PT3 magnetically couples one primary drive winding, the fifth secondary drive winding, and the sixth secondary drive winding. The output signal of the fifth secondary drive winding is an ON/OFF state of the operation switching element H3 (fourth upper arm switching element). The output signal of the sixth secondary drive winding is an ON/OFF state of the operation switching element H4 (fourth lower arm switching element). At this time, the output signals of the fifth secondary drive winding and the drive signals of the output signals of the sixth secondary drive winding complement each other, and the switching elements H3 and H4 are complementarily turned ON/OFF.

(Power supply operation of DC power supply V1 to DC power supply V2)

Hereinafter, an operation in which the switching circuit 11 and the switching circuit 15 supply electric power to the DC power source V2 and/or the DC load 16 (FIG. 1) by the DC power source V1 will be described with reference to FIGS. 3 to 8. In the following description, the DC power supply V2 and/or the DC load 16 (FIG. 1) are omitted, and the DC power supply V2 is described. This power supply operation system shows the most ideal situation. The limitation of the power supply device 10 of the first embodiment will be described later.

Among them, a voltage at both ends of the switching element in the ON state or a voltage lower than the forward voltage of the diode or less is described as "zero voltage" hereinafter. Further, when the voltage across the switching element is zero voltage, the switching element may be turned on as described below as "zero voltage switching". This zero voltage switching system suppresses switching loss (power loss) Lost) effect.

3(a) and 3(b) are diagrams showing the power supply operation (1) of the DC power supply V1 to the DC power supply V2.

Fig. 3(a) is a diagram showing a mode a of the power supply operation.

In mode a, switching elements H1 and H3 are in an ON state, and a current flowing to resonant inductor Lr flows to resonant capacitor Cr, diode DH1, switching element H3, and winding N2. Further, the switching elements S1, S2, and S4 are in an ON state, and a voltage of the DC power source V1 is applied to the smoothing inductor L1. The current flowing to the smoothing inductor L1 gradually increases. A current flows through the winding N1. The current flowing to the smoothing inductor L1 is shunted to the switching element S2 and the switching element S4 after the switching element S1 flows.

Fig. 3(b) is a diagram showing a mode b (first switching process) of the power supply operation.

When the control means 20 turns off the switching element S2, the voltage between the nodes Nd5 and Nd6 rises according to the energy accumulated in the smoothing inductor L1. When the voltage between the nodes Nd5 and Nd6 rises, the current originally flowing through the switching element S2 is diverted to the diode DS0 to charge the clamp capacitor Cc. At this time, both ends of the switching element S0 become zero voltage, and therefore the control means 20 turns on the switching element S0 (zero voltage switching). A voltage of the clamp capacitor Cc is applied to the winding N1, and a voltage is generated at the winding N2 magnetically coupled to the winding N1. The voltage generated at the winding N2 is applied to the resonant inductor Lr. Therefore, the current flowing to the resonant inductor Lr is increased. On the other hand, the current flowing to the smoothing inductor L1 is gradually reduced.

When the control means 20 holds the ON state of the switching element S1 and the switching element S4 and the OFF state of the switching element S3, the process of closing the switching element S2 is the first switching process.

4(c) and 4(d) are diagrams showing the power supply operation (2) of the DC power supply V1 to the DC power supply V2.

Fig. 4(c) is a diagram showing a mode c of the power supply operation.

When the control means 20 turns off the switching element H3, the current originally flowing through the switching element H3 flows through the diode DH4, the winding N2, the resonant inductor Lr, the resonant capacitor Cr, and the diode DH1 to the DC power supply V2. Energy is supplied to the DC power source V2 by the current flowing to the DC power source V2. At this time, the control means 20 turns on the switching element H4 (zero voltage switching). As the current flowing to the resonant inductor Lr increases, the charging current of the clamp capacitor Cc decreases, and soon becomes a discharge.

Fig. 4 (d) is a diagram showing a mode d of the power supply operation.

When the control means 20 turns off the switching element S0, the current is not supplied to the node Nd5 by the clamp capacitor Cc, so the voltage between the nodes Nd5 and Nd6 is lowered. The current originally flowing through the switching element S0 is diverted to the diodes DS2, DS3. At this time, the control means 20 turns on the switching elements S2, S3 (zero voltage switching). At the winding N1, the voltage of the clamp capacitor Cc is not applied, so that the winding N2 magnetically coupled to the winding N1 does not generate a voltage. Thereby, the voltage between the nodes Nd7 and Nd8 is applied to the resonant inductor Lr. Therefore, the current flowing to the resonant inductor Lr is reduced. Further, similarly to the mode a, the energy of the DC power source V1 is accumulated in the smoothing inductor L1. In addition, the control means 20 is in the mode d The switching element H1 is turned off.

5(e) and 5(f) are diagrams showing the power supply operation (3) of the DC power supply V1 to the DC power supply V2.

Fig. 5(e) is a diagram showing a mode e (second switching process) of the power supply operation.

The current flowing to the resonant inductor Lr is further reduced. When it reaches zero, a reverse return current flows through the diode DH1, and a current that flows in the original mode d flows in the resonant inductor Lr. Along with this, the direction of the current flowing to the winding N2 is reversed, and the direction of the current flowing to the winding N1 magnetically coupled to the winding N2 is also reversed. When the control means 20 turns off the switching element S1, the current flowing to the smoothing inductor L1 flows to the switching element S3 and is branched to the switching element S2 and the switching element S4.

The control means 20 turns on the switching elements S2, S3 while maintaining the ON state of the switching element S4, and the process of turning off the switching element S1 is the second switching process.

Fig. 5(f) is a diagram showing a mode f of the power supply operation. This mode f is a symmetrical action of mode a.

When the diode DH1 is reversely recovered, the current flowing to the resonant inductor Lr accumulated by the reverse recovery current of the diode DH1 is distributed in the winding N2, the switching element H4, the diode DH2, and the resonant capacitor Cr. . At this time, the control means 20 turns on the switching element H2 (zero voltage switching). In the mode f, the electric charge is accumulated in the resonant capacitor Cr, and a voltage is generated in a direction in which the current flowing to the resonant inductor Lr is increased. Thereby, the current flowing to the inductor Lr gradually increases.

6(g) and (h) are diagrams showing the power supply operation (4) of the DC power supply V1 to the DC power supply V2.

Fig. 6(g) is a diagram showing a mode g of the power supply operation. This mode g is a symmetric operation of mode b.

When the control means 20 turns off the switching element S4, the voltage between the nodes Nd5 and Nd6 rises according to the energy accumulated in the smoothing inductor L1. When the voltage between the nodes Nd5 and Nd6 rises, the current flowing through the switching element S4 is diverted to the diode DS0 to charge the clamp capacitor Cc. At this time, since both ends of the switching element S0 are zero voltage, the control means 20 turns on the switching element S0 (zero voltage switching). A voltage of the clamp capacitor Cc is applied to the winding N1, and a voltage is generated at the winding N2 magnetically coupled to the winding N1. The voltage generated at the winding N2 is applied to the resonant inductor Lr. Therefore, the current flowing to the resonant inductor Lr increases. On the other hand, the current flowing to the smoothing inductor L1 is gradually reduced.

Fig. 6(h) is a diagram showing a mode h of the power supply operation. This mode h is the symmetrical action of mode c.

When the control means 20 turns off the switching element H4, the current originally flowing through the switching element H4 flows to the DC power supply V2 through the diode DH2, the resonant capacitor Cr, the resonant inductor Lr, the winding N2, and the diode DH3. Energy is supplied to the DC power source V2 by the current flowing to the DC power source V2. At this time, the control means 20 turns on the switching element H3 (zero voltage switching). As the current flowing to the resonant inductor Lr increases, the current for charging the clamp capacitor Cc decreases, and soon turns to discharge.

(i) and (j) of FIG. 7 show a power supply operation (5) of the DC power supply V1 to the DC power supply V2.

Fig. 7(i) is a diagram showing a mode i of the power supply operation. This mode i is a symmetric action of mode d.

When the control means 20 turns off the switching element S0, the current does not become supplied to the node Nd5 by the clamp capacitor Cc, so the voltage between the nodes Nd5 and Nd6 drops. The current originally flowing through the switching element S0 is diverted to the diodes DS4 and DS1. At this time, the control means 20 turns on the switching elements S1, S4 (zero voltage switching). In the winding N1, the voltage of the clamp capacitor Cc is not applied, so that the winding N2 magnetically coupled to the winding N1 does not generate a voltage. Thereby, the voltage between the nodes Nd7 and Nd8 is applied to the resonant inductor Lr. Therefore, the current flowing to the resonant inductor Lr is reduced. Further, similarly to the mode f, the energy of the DC power source V1 is accumulated in the smoothing inductor L1. Further, the control means 20 turns off the switching element H2 in this mode i.

Fig. 7(j) is a diagram showing a mode j of the power supply operation. This mode j is a symmetric action of mode e.

The current flowing to the resonant inductor Lr is further reduced. When it reaches zero, the reverse recovery current flows to the diode DH2, and the resonant inductor Lr flows a current that is opposite to the current flowing in the original mode i. Along with this, the direction of the current flowing to the winding N2 is reversed, and the direction of the current flowing to the winding N1 magnetically coupled to the winding N2 is also reversed. When the control means 20 turns off the switching element S3, the current flowing to the smoothing inductor L1 flows to the switching element S1 and is branched to the switching element S2 and the switching element S4.

The next operation of the mode j is the operation of the mode a shown in Fig. 3(a), and the following operations of the modes a to j are repeated.

8(a) to (i) are diagrams showing the operation of supplying electric power to the DC power source V2 by the DC power source V1. The vertical axis indicates the ON/OFF status. When the ON/OFF state is in the ON state, it is indicated by a predetermined position on the horizontal axis passing through the origin, and in the OFF state, it is indicated on the horizontal axis passing through the origin. The horizontal axis shows all modes a~j.

Fig. 8(a) shows the ON/OFF state of the switching element H1. The switching element H1 is turned off by the switching of the mode d by the mode c, and is turned on by the switching of the mode a by the mode j.

Fig. 8(b) shows the ON/OFF state of the switching element H2. The switching element H2 is turned on by switching the mode f by the mode e, and is turned off by switching the mode i by the mode h.

Fig. 8(c) shows the ON/OFF state of the switching element H3. The switching element H3 is turned off by the switching of the mode c by the mode b, and is turned on by the switching of the mode h by the mode g.

Fig. 8(d) shows the ON/OFF state of the switching element H4. The switching element H4 is turned on by the switching of the mode c by the mode b, and is turned off by the switching of the mode h by the mode g.

Fig. 8(e) shows the ON/OFF state of the switching element S1. The switching element S1 is turned off by switching the mode e by the mode d, and is turned on by switching the mode i by the mode h.

Fig. 8(f) shows the ON/OFF state of the switching element S2. The switching element S2 is turned off by switching from the mode a to the mode b, and is utilized. It is turned on by the switching of mode c to mode d.

Fig. 8(g) shows the ON/OFF state of the switching element S3. The switching element S3 is turned on by the switching of the mode d by the mode c, and is turned off by the switching of the mode j by the mode i.

Fig. 8(h) shows the ON/OFF state of the switching element S4. The switching element S4 is turned off by switching the mode g by the mode f, and is turned on by switching the mode i by the mode h.

Fig. 8(i) shows the ON/OFF state of the switching element S0. The switching element S0 is turned on by the switching of the mode b by the mode a, and is turned off by the switching of the mode d by the mode c. Further, the switching element S0 is turned on by switching of the mode g by the mode f, and is turned off by switching of the mode i by the mode h.

The control means 20 can control the power supply operation of the DC power supply V2 by the DC power supply V1 by controlling the switching elements H1 to H4 and the switching elements S0 to S4 by the above-described model.

(Power supply operation of DC power supply V1 to DC power supply V1)

The operation of the switching circuit 11 and the switching circuit 15 to supply electric power to the DC power source V1 and/or the DC load 14 (FIG. 1) by the DC power source V2 will be described with reference to FIGS. 9 to 14 below. In the following description, the DC power supply V1 and/or the DC load 14 (FIG. 1) are omitted and described as the DC power supply V1. This power supply operation system displays the most ideal control method. The limitation of the power supply device 10 of the first embodiment is as follows.

Figure 9 (A), (B) shows the DC power supply from the DC power supply V2 The power supply operation of V1 (1) diagram.

Fig. 9(A) is a diagram showing a mode A of the power supply operation.

In mode A, switching elements H1 and H4 are in an ON state, and the voltage of DC power supply V2 is applied to winding N2 through switching elements H1 and H4, resonant capacitor Cr, and resonant inductor Lr. The voltage generated by the winding N1 magnetically coupled to the winding N2 is applied to the DC power source V1 through the diodes DS1, DS4 and the smoothing inductor L1, and the energy is supplied to the DC power source V1. Further, the voltage generated in the winding N1 is applied to the clamp capacitor Cc through the diode DS0. Therefore, the clamp capacitor Cc is charged. At this time, the control means 20 turns on the switching element S0 (zero voltage switching).

In the first embodiment, a MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) is used as the switching elements S1 to S4. Thereby, when the switching elements S1 and S4 are turned on in the power supply device 10, the current flowing in the forward direction of the diodes DS1 and DS4 can be shunted to the switching elements S1 and S4. In the power supply device 10, the resistance value of the first switching pin or the second switching pin is reduced by the shunt, and the power loss (conduction loss) of the power supply device 10 can be reduced. Hereinafter, this operation will be described as "synchronous rectification".

Fig. 9(B) is a diagram showing a mode B of the power supply operation.

The charging current of the clamp capacitor Cc is reduced, and soon changes to discharge. The discharge current of the clamp capacitor Cc is supplied to the DC power source V1 through the smoothing inductor L1.

10(C) and (D) are diagrams showing the power supply operation (2) of the DC power supply V2 to the DC power supply V1.

FIG. 10(C) is a diagram showing a mode C (third switching process) of the power supply operation.

When the control means 20 turns off the switching element H4, the current originally flowing through the switching element H4 flows to the diode DH3, the switching element H1, the resonant capacitor Cr, the resonant inductor Lr, and the winding N2. At this time, the control means 20 turns on the switching element H3 (zero voltage switching). Further, when the control means 20 turns off the switching element S0, the discharge of the clamp capacitor Cc is completed. Therefore, the voltage between the nodes Nd5 and Nd6 drops. The current originally flowing through the switching element S0 is diverted to the diodes DS2, DS3. At this time, the control means 20 turns on the switching element S2 to perform synchronous rectification. The energy accumulated in the smoothing inductor L1 is supplied to the DC power source V1.

When the control means 20 holds the ON state of the switching element S1 and the switching element S4 and the OFF state of the switching element S3, the process of turning on the switching element S2 is the third switching process.

FIG. 10(D) is a diagram showing a mode D (fourth switching process) of the power supply operation.

When the control means 20 turns off the switching element H1, the current originally flowing through the switching element H1 flows through the DC power supply V2, the diode DH2, the resonant capacitor Cr, the resonant inductor Lr, the winding N2, and the diode DH3. At this time, the control means 20 turns on the switching element H2 (zero voltage switching). The voltage of the DC power source V2 is applied to the resonant inductor Lr. Therefore, the current flowing to the resonant inductor Lr is reduced. In this embodiment, the control hand The segment 20 additionally turns on the switching element S3 and turns off the switching elements S1, S4. The control means 20 must close the switching elements S1, S4 before the end of the next mode E.

When the control unit 20 holds the ON state of the switching element S2 turned on by the third switching process, the process of turning on the switching element S3 while turning off the switching element S1 and the switching element S4 is the fourth switching process.

11(E) and (F) are diagrams showing the power supply operation (3) of the DC power supply V2 to the DC power supply V1.

Fig. 11(E) is a diagram showing a mode E of the power supply operation.

After the current flowing to the resonant inductor Lr reaches zero, the current flowing in the opposite direction to the current flowing therethrough increases. Along with this, the direction of current flowing to the winding N2 is reversed, and the current direction flowing to the winding N1 magnetically coupled to the winding N2 is reversed. The current flowing to the diodes DS1, DS4 is reduced.

Fig. 11(F) is a diagram showing a mode F of the power supply operation. This mode F is a symmetrical action of mode A.

After the current flowing to the diodes DS1 and DS4 reaches zero, a reverse recovery current flows through the diodes DS1 and DS4. The reverse recovery current is diverted to the diode DS0 when the diodes DS1 and DS4 are reversely recovered. At this time, the control means 20 turns on the switching element S0 (zero voltage switching). Further, the voltage of the DC power source V2 is applied to the winding N2. When a voltage is applied to the winding N2, a voltage is generated in the winding N1 magnetically coupled to the winding N2. The voltage generated in the winding N1 is transmitted through the diodes DS2, DS3, and flat. The slip inductor L1 is applied to the DC power source V1, and the energy is supplied to the DC power source V1. Further, the voltage generated in the winding N1 is applied to the clamp capacitor Cc through the switching element S0 and the diode DS0, and the clamp capacitor Cc is charged.

12(G) and (H) show a power supply operation (4) of the DC power supply V1 by the DC electric wire V2.

Fig. 12(G) is a diagram showing a mode G of the power supply operation. This mode G is a symmetric operation of mode B.

The charging current of the clamp capacitor Cc is reduced and soon changes to discharge. The discharge current of the clamp capacitor Cc is supplied to the DC power source V1 through the smoothing inductor L1.

Fig. 12 (H) is a diagram showing a mode H of the power supply operation. This mode H is a symmetrical action of mode C.

When the control means 20 turns off the switching element H3, the current flowing through the switching element H3 flows to the winding N2, the resonant inductor Lr, the resonant capacitor Cr, the switching element H2, and the diode DH4. At this time, the control means 20 turns on the switching element H4 (zero voltage switching). Further, when the control means 20 turns off the switching element S0, the discharge of the clamp capacitor Cc is completed. Therefore, the voltage between the nodes Nd5 and Nd6 drops. The current originally flowing through the switching element S0 is diverted to the diodes DS1, DS4. At this time, the control means 20 turns on the switching element S4 to perform synchronous rectification. The energy accumulated in the smoothing inductor L1 is supplied to the DC power source V1.

13(I) and (J) show a power supply operation (5) of the DC power supply V2 to the DC power supply V1.

Fig. 13 (I) is a diagram showing a mode I of the power supply operation. This mode is the symmetrical action of mode D.

When the control means 20 turns off the switching element H2, the current originally flowing through the switching element H2 flows through the direct current power source V2, the diode DH1, the resonance capacitor Cr, the resonant inductor Lr, the winding N2, and the diode DH4. At this time, the control means 20 turns on the switching element H1 (zero voltage switching). The voltage of the DC power source V2 is applied to the resonant inductor Lr. Therefore, the current flowing to the resonant inductor Lr is reduced. In the present embodiment, the control means 20 additionally turns on the switching element S1 and turns off the switching elements S2, S3. The control means 20 must close the switching elements S2, S3 before the end of the next mode J.

Fig. 13 (J) is a diagram showing a mode J of the power supply operation. This mode is a symmetrical action of the J system mode E.

After the current flowing to the resonant inductor Lr reaches zero, the current flowing in the reverse direction to the current flowing to the original time increases. Along with this, the direction of the current flowing to the winding N2 is reversed, and the direction of the current flowing to the winding N1 magnetically coupled to the winding N2 is also reversed. The current flowing to the diodes DS2 and DS3 is reduced.

14(a) to (i) are diagrams showing the operation of supplying electric power to the DC power source V1 by the DC power source V2. The vertical axis indicates the ON/OFF status. The horizontal axis represents all modes A~J.

Fig. 14 (a) shows the ON/OFF state of the switching element H1. The switching element H1 is turned off by the switching of the mode D by the mode C, and is turned on by the switching of the mode I by the mode H.

Fig. 14 (b) shows the ON/OFF state of the switching element H2. The switching element H2 is turned on by the switching of the mode D by the mode C, and is turned off by the switching of the mode I by the mode H.

Fig. 14 (c) shows the ON/OFF state of the switching element H3. The switching element H3 is turned on by the switching of the mode C by the mode B, and is turned off by the switching of the mode H by the mode G. Among them, the switching element H3 can also be turned on by switching the mode D by the mode C.

Fig. 14 (d) shows the ON/OFF state of the switching element H4. The switching element H4 is turned off by the switching of the mode C by the mode B, and is turned on by the switching of the mode H of the mode G. Among them, the switching element H4 can also be turned on by switching the mode I by the mode H.

Fig. 14(e) shows the ON/OFF state of the switching element S1. The switching element S1 is turned off by the switching of the mode D by the mode C, and is turned on by the switching of the mode I by the mode H. The switching element S1 may be turned off by switching the mode E by the mode D or by switching the mode F by the mode E, or may be turned on by switching the mode H by the mode G.

Fig. 14 (f) shows the ON/OFF state of the switching element S2. The switching element S2 is turned on by the switching of the mode C by the mode B, and is turned off by the mode H pair switching of the mode I. The switching element S2 can also be turned off by switching the mode J by the mode I or switching the mode A by the mode J.

Fig. 14 (g) shows the ON/OFF state of the switching element S3. The switching element S3 is turned on by switching the mode D by the mode C, and utilizes It is turned off by the switching of mode H to mode 1. The switching element S3 can also be turned on by switching the mode C by the mode B, or can be turned off by switching the mode J by the mode I or switching the mode A by the mode J.

Fig. 14 (h) shows the ON/OFF state of the switching element S4. The switching element S4 is turned off by switching the mode D by the mode C, and is turned on by the switching of the mode H by the mode G. The switching element S4 can also be turned off by switching the mode E by the mode D or switching the mode F by the mode E.

Fig. 14 (i) shows the ON/OFF state of the switching element S0. The switching element S0 is turned off by the switching of the mode C by the mode B, and is turned on by the switching of the mode F by the mode E. Further, the switching element S0 is turned off by switching of the mode H by the mode G, and is turned on by switching of the mode A by the mode J.

The control means 20 can control the power supply operation of the DC power supply V1 by the DC power supply V2 by controlling the switching elements H1 to H4 and the switching elements S0 to S4 by the above-described model.

(Operation of the first embodiment)

In the power supply operation of the DC power supply V2 by the DC power supply V1, the magnitude of the output power is adjusted by changing the length of the period from the closing of the switching element S0 to the closing of the switching element S4, that is, the mode d to f. The switching element S1 may be turned off from the start of the mode d to the end of the mode f. The effect of the off timing on the magnitude of the output power Less loud. Therefore, the switching element S1 can also be turned off while the switching element S3 in the mode d is turned on, or turned off after a certain time.

Similarly, the switching element S3 can also be turned off during the symmetry of the mode d, that is, the switching element S1 in the mode i is turned off, or turned off after a certain time.

In other words, the switching element S1 and the switching element S3 can be controlled to be ON/OFF while being complementary to each other while being in the ON state. The switching elements S1 and S3 can be operated by one pulse transformer PT1.

(Effects of the first embodiment)

In the first embodiment described above, the effects shown in the following (A) to (D) are obtained.

(A) The power supply device 10 controls the ON/OFF state of the switching elements S0 to S4 and the ON/OFF states of the switching elements H1 to H4 by a predetermined model, thereby switching the power of the DC power source V1 to the DC power source V2. The supply operation and the power supply operation to the DC power supply V1 by the DC power supply V2 are performed.

(B) The power supply device 10 can operate the ON/OFF state of the two switching elements S1 and S3 by one pulse transformer PT1, thereby simplifying the drive circuit and achieving downsizing and cost reduction.

(C) The power supply device 10 can operate the ON/OFF state of the two switching elements H1 and H2 by one pulse transformer PT2, thereby simplifying the drive circuit and achieving downsizing and cost reduction.

(D) The power supply unit 10 can be operated by one pulse transformer PT3 In the ON/OFF state of the two switching elements H3 and H4, the drive circuit is simplified, and the size and cost are reduced.

(Configuration of Second Embodiment)

In the power supply device 10 of the second embodiment, the power loss is suppressed in the power supply operation of the DC power supply V1 by the DC power supply V2 as compared with the power supply device 10 of the first embodiment shown in FIG.

The configuration of the power supply device 10 of the second embodiment is different from that of the power supply device 10 (FIG. 1) of the first embodiment, and is connected between the pulse transformer PT1 (FIG. 1) and the switching elements S1 and S3 (FIG. 1). Delay circuits 40, 41 (Fig. 15). The other configuration is the same as that of the power supply device 10 (FIG. 1) of the first embodiment.

Fig. 15 is a view showing a schematic configuration of a switching element control circuit in the second embodiment.

The switching element control circuit in the second embodiment is an example of a circuit that is complementary to ON/OFF while ensuring that the switching element S1 and the switching element S3 are simultaneously in an ON state.

The switching element control circuit in the second embodiment includes a pulse transformer PT1, a turn-off delay circuit 40, and a turn-off delay circuit 41.

One of the output sides of the pulse transformer PT1 is connected to the control terminal of the switching element S1 through the turn-off delay circuit 40. Further, the other output side of the pulse transformer PT1 is connected to the control terminal of the switching element S3 through the turn-off delay circuit 41.

The off delay circuits 40, 41 are connected to the input signal When the models of the elements S1, S3 are switched, the input signal model is output without delay. When the input signal is the model for switching the switching elements S1 and S3, the input signal model is output after a predetermined delay time.

(Operation of the second embodiment)

In the power supply operation of the DC power supply V1 by the DC power supply V2, the magnitude of the output power is adjusted by changing the period of the mode C. Mode C is omitted if the output power is formed to the maximum.

In the modes D and E in the power supply operation of the DC power supply V2 to the DC power supply V1, even if the switching element S1 and the switching element S3 are simultaneously turned into an ON state, synchronous rectification is performed without causing a problem.

In the second embodiment, when the pulse transformer PT1 outputs a signal for simultaneously turning on the switching element S3 and turning off the switching element S1, the off timing of the switching element S1 is slowed by turning off the delay circuit 40, so the switching element S3 is switched. After being turned on, the switching element S1 is turned off. The length of the period in which the switching element S1 and the switching element S3 are simultaneously in the ON state may be shorter than the length of the period from the start of the mode C to the end of the mode E.

Similarly, if the pulse transformer PT1 outputs a signal for simultaneously turning on the switching element S1 and turning off the switching element S3, since the switching timing of the switching element S3 is slowed down by turning off the delay circuit 41, after the switching element S1 is turned on, The switching element S2 is closed. When the switching element S1 and the switching element S3 are simultaneously in the ON state, the length is longer than the slave mode G. The length of the period from the start of the mode to the end of the mode J may be short.

As described above, the control means 20 of the second embodiment can control both the switching element S1 and the switching element S3 without increasing the power loss (conduction loss).

Further, the resonance capacitor Cr of the power supply device 10 of the second embodiment has an effect of removing the DC component of the current flowing to the winding N2 to reduce the bias of the transformer T1.

(Effect of the second embodiment)

In the second embodiment described above, the effects of the following (E) to (G) are obtained.

(E) The power supply device 10 operates the ON/OFF states of the two upper arm switching elements S1 and S3 by one pulse transformer PT1 and the shutdown delay circuits 40 and 41. Thereby, the power supply device 10 can simplify the drive circuits of the upper arm switching elements S1 and S3, thereby achieving downsizing and cost reduction.

(F) A resonance capacitor Cr is provided in the switching circuit 15. Thereby, the power supply device 10 can remove the DC component of the current flowing to the winding N2 to reduce the bias of the transformer T1.

(G) The power supply device 10 performs the synchronous rectification by diverting the currents flowing to the diodes DS1 and DS4 to the switching elements S1 and S4 in modes A, C, and H. Thereby, the power supply device 10 can reduce power loss (conduction loss).

(Modification)

The present invention is not limited to the embodiments described above, and may be modified and implemented without departing from the spirit and scope of the invention. In the use form or modification, for example, as shown in the following (a) to (e).

(a) The switching circuit 15 of the first embodiment and the second embodiment will be described as a full bridge circuit. However, the present invention is not limited thereto, and the switching circuit 15 may be applied to another circuit method that can rectify the voltage generated in the winding N2.

(b) The winding N1 connected to the AC terminal of the switching circuit 11 may be applied to a case where the AC power is supplied to the AC load by the DC power supply V1.

(c) When a MOSFET is used as the switching elements S0 to S4, a parasitic diode of the MOSFET can be used. Therefore, the switching elements S0 to S4 can also omit the connection of the diodes DS0 to DS4.

(d) When a MOSFET is used as the switching elements H1 to H4, a parasitic diode of the MOSFET can be used. Therefore, the switching elements H1 to H4 can also omit the connection of the diodes DH1 to DH4.

(e) The power supply device 10 according to the first embodiment may be a device that converts electric power supplied from a DC power source. For example, an uninterruptible power supply device, a residential emergency power supply, or the like may be used. Further, the power supply device 10 is not limited to the purpose of the backup power supply when the power supply is abnormal, and may be a system that uses the power leveling system or a system that stores the nighttime power and uses it during the day.

10‧‧‧Power supply unit

11‧‧‧Switching circuit (1st switching circuit)

12‧‧‧Voltage Clamp Circuit

13‧‧‧Optocoupler (insulation means)

14‧‧‧DC load

15‧‧‧Switching circuit (2nd switching circuit)

16‧‧‧DC load

20‧‧‧Control means

30‧‧‧One drive winding

31, 32‧‧‧ secondary drive winding

33‧‧‧Magnetic core

40‧‧‧ Turn off the delay circuit (1st off delay circuit)

41‧‧‧ Turn off the delay circuit (2nd off delay circuit)

C1‧‧‧Smoothing capacitor (first smoothing capacitor)

C2‧‧‧Smoothing capacitor (2nd smoothing capacitor)

Cc‧‧‧Clamp Capacitor

Cr‧‧‧Resonance Capacitor

DH1~DH4‧‧‧ Diode

DS0~DS4‧‧‧ diode

H1‧‧‧Switching element (3rd upper arm switching element)

H2‧‧‧Switching element (3rd upper arm switching element)

H3‧‧‧Switching element (4th upper arm switching element)

H4‧‧‧Switching element (4th lower arm switching element)

L1‧‧‧Smooth Inductors

Lr‧‧‧Resonance Inductors

N1‧‧‧ winding (primary winding)

N2‧‧‧ winding (secondary winding)

Nd1, Nd2‧‧‧ nodes (between the first AC terminals)

Nd3, Nd4‧‧‧ nodes (between the 2nd DC terminals)

Nd5, Nd6‧‧‧ nodes (between the first DC terminals)

Nd7, Nd8‧‧‧ nodes (between the 2nd AC terminals)

PT1‧‧‧pulse transformer (1st pulse transformer)

PT2‧‧‧pulse transformer (2nd pulse transformer)

PT3‧‧‧ pulse transformer (3rd pulse transformer)

S0‧‧‧Switching components

S1‧‧‧Switching element (first upper arm switching element)

S2‧‧‧Switching element (1st lower arm switching element)

S3‧‧‧Switching element (2nd upper arm switching element)

S4‧‧‧Switching element (2nd lower arm switching element)

T1‧‧‧ Transformer (main transformer)

V1‧‧‧DC power supply (1st DC power supply)

V2‧‧‧DC power supply (2nd DC power supply)

Fig. 1 is a schematic block diagram showing a power supply device according to a first embodiment.

Fig. 2 is a schematic block diagram showing a pulse transformer in the first embodiment.

Fig. 3 is a view showing a power supply operation (1) of the DC power source V1 to the DC power source V2.

Fig. 4 is a view showing a power supply operation (2) of the DC power supply V2 to the DC power supply V2.

Fig. 5 is a view showing a power supply operation (3) of the DC power source V1 to the DC power source V2.

Fig. 6 is a view showing a power supply operation (4) of the DC power source V1 to the DC power source V2.

Fig. 7 is a view showing a power supply operation (5) of the DC power source V1 to the DC power source V2.

Fig. 8 is a view showing the operation of supplying electric power from the DC power source V1 to the DC power source V2.

Fig. 9 is a view showing a power supply operation (1) of the DC power source V2 to the DC power source V1.

Fig. 10 is a view showing a power supply operation (2) of the DC power source V2 to the DC power source V1.

Fig. 11 is a view showing a power supply operation (3) of the DC power source V2 to the DC power source V1.

Fig. 12 is a view showing a power supply operation (4) of the DC power source V2 to the DC power source V1.

Fig. 13 is a view showing a power supply operation (5) of the DC power source V2 to the DC power source V1.

Fig. 14 is a view showing the operation of supplying electric power to the DC power source V1 by the DC power source V2.

Fig. 15 is a view showing a schematic configuration of a switching element control circuit in the second embodiment.

10‧‧‧Power supply unit

11‧‧‧Switching circuit (1st switching circuit)

12‧‧‧Voltage Clamp Circuit

13‧‧‧Optocoupler (insulation means)

14‧‧‧DC load

15‧‧‧Switching circuit (2nd switching circuit)

16‧‧‧DC load

20‧‧‧Control means

C1‧‧‧Smoothing capacitor (first smoothing capacitor)

C2‧‧‧Smoothing capacitor (2nd smoothing capacitor)

Cc‧‧‧Clamp Capacitor

Cr‧‧‧Resonance Capacitor

DH1~DH4‧‧‧ Diode

DS0~DS4‧‧‧ diode

H1‧‧‧Switching element (3rd upper arm switching element)

H2‧‧‧Switching element (3rd upper arm switching element)

H3‧‧‧Switching element (4th upper arm switching element)

H4‧‧‧Switching element (4th lower arm switching element)

L1‧‧‧Smooth Inductors

Lr‧‧‧Resonance Inductors

N1‧‧‧ winding (primary winding)

N2‧‧‧ winding (secondary winding)

Nd1, Nd2‧‧‧ nodes (between the first AC terminals)

Nd3, Nd4‧‧‧ nodes (between the 2nd DC terminals)

Nd5, Nd6‧‧‧ nodes (between the first DC terminals)

Nd7, Nd8‧‧‧ nodes (between the 2nd AC terminals)

PT1‧‧‧pulse transformer (1st pulse transformer)

PT2‧‧‧pulse transformer (2nd pulse transformer)

PT3‧‧‧ pulse transformer (3rd pulse transformer)

S0‧‧‧Switching components

S1‧‧‧Switching element (first upper arm switching element)

S2‧‧‧Switching element (1st lower arm switching element)

S3‧‧‧Switching element (2nd upper arm switching element)

S4‧‧‧Switching element (2nd lower arm switching element)

T1‧‧‧ Transformer (main transformer)

V1‧‧‧DC power supply (1st DC power supply)

V2‧‧‧DC power supply (2nd DC power supply)

Claims (17)

A power supply device including: a first switching circuit in which a smoothing inductor and a first smoothing capacitor are connected in series between first DC terminals; and an ON/OFF state in which a switching element provided in the first switching circuit is controlled In the control device, the power supply device is characterized in that a first switching in which the first upper arm switching element and the first lower arm switching element are connected in series is connected in parallel between the first DC terminals of the first switching circuit. a second switching pin that connects the second upper arm switching element and the second lower arm switching element in series, a series connection point of the first upper arm switching element and the first lower arm switching element, and the foregoing a series connection point between the upper arm switching element and the second lower arm switching element is a first AC terminal, and an AC load is connected between the first AC terminals, and the control means is to hold the first upper arm switching element and the aforementioned When the ON state of the second lower arm switching element and the OFF state of the second upper arm switching element are performed, the first switching process of closing the first lower arm switching element is performed. The power supply device according to claim 1, wherein the control means performs the opening of the first lower arm switch when the first lower arm switching element is kept in the ON state after the first switching process is executed. The element and the second upper arm switching element further close the second switching process of the first upper arm switching element. In the power supply device of the second aspect of the invention, in the second switching process, the first upper arm switching element is changed to the OFF state, and the second upper arm switching element is changed to the ON state. The power supply device according to any one of claims 1 to 3, further comprising: a first pulse transformer connected to the control means and having a first voltage applied between both ends The primary drive winding is magnetically coupled to the first secondary drive winding and the second secondary drive winding, and the first pulse transformer controls the first upper arm by an output signal of the first secondary drive winding Controlling an ON/OFF state of the switching element, and controlling an ON/OFF state of the second upper arm switching element by an output signal of the second secondary driving winding, an output signal of the first secondary driving winding, and the foregoing The output signals of the second secondary drive winding are complementary. The power supply device of claim 4, wherein a first shutdown delay circuit is connected to the first secondary drive winding of the first pulse transformer, and the first shutdown delay circuit is configured to be the first a closing delay of an output signal of the secondary drive winding, and a second shutdown delay circuit connected to the second secondary drive winding, wherein the second shutdown delay circuit outputs an output signal of the second secondary drive winding Turn off the delay. The power supply device according to any one of claims 1 to 5, wherein the first upper arm switching element, the first lower arm switching element, the second upper arm switching element, and the second lower arm switch Component system There are diodes connected to each other in anti-parallel connection. The power supply device according to any one of claims 1 to 6, wherein the first switching circuit includes a voltage clamping circuit connected to the first DC terminal. The power supply device of claim 7, wherein the voltage clamping circuit is provided with a switching element and a capacitor that are connected at least in series. The power supply device according to any one of claims 1 to 8, further comprising: a main transformer that magnetically couples the alternating current load as a primary winding to the secondary winding; the second switching circuit The DC load and the second smoothing capacitor are connected in parallel between the second DC terminals, and the third upper arm switching element and the third lower arm switching element are connected in parallel between the second DC terminals of the second switching circuit. a third switching pin connected in series, and a fourth switching pin connecting the fourth upper arm switching element and the fourth lower arm switching element in series, in the third upper arm switching element and the third lower arm switching element The second connection is connected between the series connection point and the series connection point between the fourth upper arm switching element and the fourth lower arm switching element, that is, between the second AC terminals, and the control means separately controls the second switching The third upper arm switching element, the third lower arm switching element, the fourth upper arm switching element, and the fourth lower arm switching element of the circuit are turned ON/OFF. state. A power supply device according to claim 9, comprising a second pulse transformer connected to the control means, and a second primary drive winding to which a voltage is applied between both ends, and the third upper arm are operated The third secondary drive winding of the switching element in the ON/OFF state and the fourth secondary drive winding that operates the ON/OFF state of the third lower arm switching element are magnetically coupled to the third secondary drive winding. The output signal is complementary to the output signal of the fourth secondary drive winding. The power supply device of claim 9, comprising a third pulse transformer connected to the control means, and a third primary drive winding to which a voltage is applied between both ends, and the fourth upper arm are operated The fifth secondary drive winding of the switching element in the ON/OFF state and the sixth secondary drive winding that operates the ON/OFF state of the fourth lower arm switching element are magnetically coupled to the fifth secondary drive winding. The output signal is complementary to the output signal of the sixth secondary winding of the foregoing. The power supply device according to any one of the preceding claims, wherein the third upper arm switching element, the third lower arm switching element, the fourth upper arm switching element, and the fourth lower arm switch The components are provided with diodes that are connected in anti-parallel with each. Such as the power supply of any of the scope of claim 9 to 11 The device may be configured to: supply power to a load connected between the first DC terminals by a power source connected between the second DC terminals, and a power source connected between the first DC terminals The process of supplying electric power to the load connected between the second DC terminals is switched and executed. The power supply device according to any one of claims 9 to 13, further comprising a resonance capacitor and/or a resonant inductor connected in series to the primary winding and/or the secondary winding. A power supply device comprising: a first switching circuit in which a primary winding is connected between AC terminals, and a smoothing inductor and a smoothing capacitor are connected in series between the DC terminals; and a voltage of the DC power source is converted into an alternating current and applied to the second a second switching circuit of the secondary winding; a transformer that magnetically couples the primary winding and the secondary winding; and a control means for controlling an ON/OFF state of the switching element provided in the first and second switching circuits, The power supply device supplies electric power to a DC load that is connected in parallel with the smoothing capacitor. The power supply device is characterized in that the first switching circuit includes a first upper arm switching element and a first lower arm switching element that are connected in series. a switching pin, and a second switching pin that connects the second upper arm switching element and the second lower arm switching element in series and is connected in parallel to the first switching pin, and connects the two ends of the first switching pin a tandem connection point between the first upper arm switching element and the first lower arm switching element, and the second upper arm switching element and the second An arm disposed between the switching elements of the series connection point The control means is configured to open the first lower arm while maintaining the ON state of the first upper arm switching element and the second lower arm switching element and the OFF state of the second upper arm switching element. The third switching process of the switching element. The power supply device of claim 15, wherein the control means performs the closing of the first upper arm while holding the ON state of the first lower arm switching element opened by the third switching process The switching device and the second lower arm switching element turn on the fourth switching process of the second upper arm switching element. A method of controlling a power supply device including: a smoothing inductor and a first switching circuit in which a first smoothing capacitor is connected in series between first DC terminals; and controlling ON/ of a switching element provided in the first switching circuit In the OFF state control means, the first switching pin for connecting the first upper arm switching element and the first lower arm switching element in series is connected in parallel between the first DC terminals of the first switching circuit, and a second switching pin in which the upper arm switching element and the second lower arm switching element are connected in series, a series connection point of the first upper arm switching element and the first lower arm switching element, and the second upper arm switching element and the aforementioned A series connection point of the second lower arm switching element is a method of controlling a power supply device in which an alternating current load is connected between the first alternating current terminals, and is characterized in that: The control means performs the first closing of the first lower arm switching element while maintaining the ON state of the first upper arm switching element and the second lower arm switching element and the OFF state of the second upper arm switching element. Switch processing.