Power supply device, and program

Abstract

To solve the problem that a heavy load is applied on a switch when cutting off electrical connection between an input terminal and an output terminal.SOLUTION: A power supply device 10 comprises an input terminal capable of connecting a DC power supply, an output terminal, a power conversion circuit 13, a first switch 21 arranged between the input terminal and the power conversion circuit, a second switch 22 arranged between the power conversion circuit 13 and the output terminal, and a control part 40 capable of switching each of the first switch 21 and the second switch 22 between an on-state and an off-state. When cutting off electrical connection between the input terminal and the output terminal, the control part 40 switches the second switch 22 to the off-state after switching the first switch 21 to the off-state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply device and a program. [Background technology]

[0002] The power supply device disclosed in Patent Document 1 includes a high-voltage battery, a low-voltage battery, and a DC-DC converter connected between these two batteries. The DC-DC converter has a step-down function for sending power from the high-voltage battery to the low-voltage battery, and a step-up function for sending power from the low-voltage battery to the high-voltage battery.

[0003] Furthermore, the power supply device disclosed in Patent Document 1 includes two semiconductor switches for protecting a circuit, and a voltage control unit for controlling each semiconductor switch. One of the two semiconductor switches is connected between the DC-DC converter and a high-potential terminal of a high-voltage battery. The other of the two semiconductor switches is connected between the DC-DC converter and a high-potential terminal of a low-voltage battery. For example, when the high-voltage battery and the low-voltage battery are connected to the DC-DC converter in an interchangeable manner, the voltage control unit switches one or both of the two semiconductor switches to the off state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-135478 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a power supply device such as that described in Patent Document 1, if a semiconductor switch is switched off while a DC-DC converter is operating, a load may be placed on the semiconductor switch. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention is a power supply device comprising an input terminal to which a DC power supply can be connected, an output terminal, a power conversion circuit arranged between the input terminal and the output terminal, a first switch arranged between the input terminal and the power conversion circuit, a second switch arranged between the power conversion circuit and the output terminal, and a control unit that controls the first switch and the second switch, wherein when the electrical connection between the input terminal and the output terminal is cut off, the control unit switches the first switch to an off state and then switches the second switch to an off state.

[0007] The present invention is also applicable to a power supply device including an input terminal to which a DC power supply can be connected, an output terminal, a power conversion circuit arranged between the input terminal and the output terminal, a possible first switch arranged between the input terminal and the power conversion circuit, a second switch arranged between the power conversion circuit and the output terminal, and a control unit that controls the first switch and the second switch, and is a program that causes the control unit to execute a process of switching the first switch to an off state and then switching the second switch to an off state when the electrical connection between the input terminal and the output terminal is cut off. Effect of the Invention

[0008] When the electrical connection between the input terminal and the output terminal is cut off, the load on the switch can be reduced. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a circuit diagram of a power supply device. [Diagram 2] FIG. 2 is a circuit diagram illustrating the operation of the power supply device. [Diagram 3] FIG. 3 is a circuit diagram illustrating a comparative example of the operation of the power supply device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <One embodiment of a power supply device and a program> An embodiment of a power supply device and a program will be described below. (About the power supply) As shown in FIG. 1, the power supply device 10 includes a high potential input terminal 11A, a low potential input terminal 11B, a high potential output terminal 12A, a low potential output terminal 12B, a high potential power supply line LA, and a low potential power supply line LB.

[0011] The high potential input terminal 11A and the low potential input terminal 11B can be connected to a battery 50 as a DC power supply. Specifically, the high potential input terminal 11A is connected to the positive terminal of the battery 50. The low potential input terminal 11B is connected to the negative terminal of the battery 50. The battery 50 is, for example, a lithium ion battery.

[0012] The high potential output terminal 12A is connected to the high potential input terminal 11A via a high potential power supply line LA. The low potential output terminal 12B is connected to the low potential input terminal 11B via a low potential power supply line LB. The high potential output terminal 12A and the low potential output terminal 12B can be connected to a load 60. The load 60 operates on a DC voltage from the power supply device 10. The load 60 is, for example, a server or storage in a data center. Therefore, power is supplied from the battery 50 to the load 60 via each input terminal, each power supply line, and each output terminal. The potentials of the low potential output terminal 12B and the low potential power supply line LB are ground potential.

[0013] The power supply device 10 includes an input capacitor C. The input capacitor C is an electrolytic capacitor. A positive terminal of the input capacitor C is connected to a high potential input terminal 11A. A negative terminal of the input capacitor C is connected to a low potential input terminal 11B.

[0014] The power supply device 10 includes a power conversion circuit 13 disposed between each input terminal and each output terminal. The power conversion circuit 13 is located on a high potential power supply line LA and a low potential power supply line LB. Specifically, the power conversion circuit 13 includes an inductor L, a first switching element SW1, and a second switching element SW2. Each switching element is an n-channel type MOSFET (metal oxide semiconductor field effect transistor). A first end of the inductor L is connected to a high potential input terminal 11A. A source terminal of the first switching element SW1 is connected to a low potential input terminal 11B and a low potential output terminal 12B via a low potential power supply line LB. A drain terminal of the first switching element SW1 is connected to a second end of the inductor L. A source terminal of the second switching element SW2 is connected to the second end of the inductor L and the drain terminal of the first switching element SW1. A drain terminal of the second switching element SW2 is connected to a high potential output terminal 12A.

[0015] The power supply device 10 includes a first switch 21 and a second switch 22. The first switch 21 and the second switch 22 are both located on the high potential power line LA, and can be switched between an on state and an off state.

[0016] The first switch 21 is disposed between the high potential input terminal 11A on the high potential power supply line LA and the power conversion circuit 13. Specifically, the first switch 21 is disposed between the high potential input terminal 11A and a first end of the inductor L. Therefore, the source terminal of the second switching element SW2 of the power conversion circuit 13 is connected to the first switch 21 via the inductor L. In other words, the second switching element SW2 is a third switch 23 in which the anode side terminal of the body diode is connected to the first switch 21.

[0017] In each drawing, the first switch 21 is illustrated as a single-pole short-throw switch, but in reality, the first switch 21 is composed of a plurality of switching elements. Specifically, the first switch 21 includes a plurality of bidirectional switches connected in parallel. The bidirectional switches are, for example, n-channel MOSFETs whose source terminals are connected to each other.

[0018] The off state of the first switch 21 refers to a state in which the first switch 21 as a whole does not allow current to flow from the input terminal side to the output terminal side, and does not allow current to flow from the output terminal side to the input terminal side, regardless of the combination of the on states and off states of each switch element that constitutes the first switch 21.

[0019] The second switch 22 is disposed between the power conversion circuit 13 on the high potential power supply line LA and the high potential output terminal 12A. Specifically, the second switch 22 is disposed between the drain terminal of the second switching element SW2 of the power conversion circuit 13 and the high potential output terminal 12A.

[0020] The second switch 22 is a bidirectional switch. Specifically, the second switch 22 includes a fourth switch 24 connected to the power conversion circuit 13, and a fifth switch 25 disposed between the fourth switch 24 and the high potential output terminal 12A. The fourth switch 24 and the fifth switch 25 are both n-channel MOSFETs. The drain terminal of the fourth switch 24 is connected to the drain terminal of the second switching element SW2. The source terminal of the fourth switch 24 is connected to the source terminal of the fifth switch 25. The drain terminal of the fifth switch 25 is connected to the high potential output terminal 12A. Therefore, the second switch 22 is composed of two n-channel MOSFETs whose source terminals are connected to each other. In other words, the fourth switch 24 and the fifth switch 25 are connected in series so that the anode side terminals of the body diodes of the fourth switch 24 and the fifth switch 25 are connected to each other. That is, the fourth switch 24 and the fifth switch 25 are connected so that the body diodes are oriented in opposite directions.

[0021] The off state of the second switch 22 refers to a state in which the second switch 22 as a whole does not allow a current to flow from the input terminal side to the output terminal side and does not allow a current to flow from the output terminal side to the input terminal side, regardless of the combination of the on states and off states of the fourth switch 24 and the fifth switch 25 that constitute the second switch 22. In other words, the off state of the second switch 22 refers to a state in which the fourth switch 24 is off and the fifth switch 25 is also off.

[0022] 1, the power supply device 10 has a control unit 40 that controls the first switch 21, the second switch 22, and the third switch 23. The control unit 40 can output control signals that switch on and off each switching element of the power conversion circuit 13. Specifically, the control unit 40 outputs a first control signal S1 that switches on and off the first switching element SW1 of the power conversion circuit 13. The control unit 40 outputs a second control signal S2 that switches on and off the second switching element SW2 of the power conversion circuit 13.

[0023] The control unit 40 outputs a control signal for switching between the on state and the off state of the first switch 21. Specifically, the control unit 40 outputs a plurality of control signals MS corresponding to each switching element constituting the first switch 21, thereby switching on and off each switching element individually.

[0024] The control unit 40 outputs a control signal for switching the second switch 22 between an on state and an off state. Specifically, the control unit 40 outputs a third control signal S3 for switching the fourth switch 24 between on and off. The control unit 40 outputs a fourth control signal S4 for switching the fifth switch 25 between on and off.

[0025] The control unit 40 has a storage device and an arithmetic processing device, not shown. In other words, the control unit 40 is an MCU (Microcontroller Unit). The storage device of the control unit 40 stores a program PG executed by the arithmetic processing device. The arithmetic processing device executes the program PG to switch the first switch 21, the second switch 22, and each switching element of the power conversion circuit 13 between on and off states by switching control, which will be described later. The arithmetic processing device includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit).

[0026] (About switching control) Next, the switching control by the control unit 40 will be described. The switching control is a control for switching between the on state and the off state of each switch or each switching element. This switching control is performed by the arithmetic processing unit executing a program PG stored in the storage device of the control unit 40.

[0027] The control unit 40 acquires an output voltage, which is a potential difference between each output terminal, while the power supply device 10 is operating. For example, when the high potential output terminal 12A and the low potential output terminal 12B are shorted, the potential difference between the high potential output terminal 12A and the low potential output terminal 12B becomes small. When the potential difference between each output terminal becomes equal to or less than a predetermined threshold, the arithmetic processing device of the control unit 40 executes a series of switching controls to cut off the electrical connection between the high potential input terminal 11A and the high potential output terminal 12A.

[0028] When the control unit 40 starts to execute the switching control based on the program PG, the control unit 40 first switches the first switch 21 to the OFF state. The time from the start of the execution of the switching control to the switching of the first switch 21 to the OFF state is less than 1 millisecond.

[0029] Next, the control unit 40 switches the second switching element SW2, among the switching elements of the power conversion circuit 13, to the OFF state. As described above, the second switching element SW2 is the third switch 23 in which the anode side terminal of the body diode is connected to the first switch 21. After that, the control unit 40 switches the fifth switch 25 to the OFF state. Note that the time from switching the first switch 21 to the OFF state to switching the second switching element SW2 to the OFF state is less than 1 millisecond. The time from switching the second switching element SW2 to the OFF state to switching the fifth switch 25 to the OFF state is less than 1 millisecond.

[0030] Next, the control unit 40 switches the fourth switch 24 to the OFF state. The time from switching the second switching element SW2 and the fifth switch 25 to the OFF state to switching the fourth switch 24 to the OFF state is longer than the time from switching the first switch 21 to the OFF state to switching the second switching element SW2 and the fifth switch 25 to the OFF state. Specifically, the time from switching the second switching element SW2 and the fifth switch 25 to the OFF state to switching the fourth switch 24 to the OFF state is 1 millisecond or more and less than 100 milliseconds. When the fourth switch 24 is switched to the OFF state, the switching control ends.

[0031] In this manner, in the above switching control, the control unit 40 switches the second switching element SW2 serving as the third switch 23 to the off state after switching the first switch 21 to the off state and before switching the second switch 22 to the off state. Then, after switching the fifth switch 25 to the off state, the control unit 40 switches the fourth switch 24 to the off state, thereby switching the second switch 22 to the off state.

[0032] (Switching control action) When the control unit 40 cuts off the electrical connection between the high potential input terminal 11A and the high potential output terminal 12A, the control unit 40 first switches the first switch 21 to the OFF state. This prevents a short-circuit current from flowing to a DC power source such as a battery 50 connected to the input terminal. When the power supply device 10 is operating, electrical energy is stored in the inductor L. Meanwhile, an input capacitor C is interposed between the first switch 21 and the inductor L. Therefore, even if the first switch 21 is turned off, a current based on the energy stored in the inductor L does not conduct through the first switch 21.

[0033] Next, as shown in FIG. 2, the control unit 40 switches the second switching element SW2 as the third switch 23 and the fifth switch 25 to the off state. At this time, the body diode of the second switching element SW2 and the body diode of the fifth switch 25 allow current to flow to the high potential output terminal 12A side. In FIG. 2, the switching element in the off state that allows current to flow to the high potential output terminal 12A side is illustrated as a diode. As a result, the current based on the energy stored in the inductor L and the like flows through the body diode of the second switching element SW2 and the body diode of the fifth switch 25. That is, at least a part of the energy stored in the inductor L is consumed by the resistance of the body diode of each switching element.

[0034] In the switching control, a predetermined time is provided between when the second switching element SW2 and the fifth switch 25 are switched to the OFF state and when the fourth switch 24 is switched to the OFF state. This ensures a sufficient time for current to flow through the body diode of the second switching element SW2 and the body diode of the fifth switch 25.

[0035] 3, it is assumed that after the first switch 21 is turned off, only the fourth switch 24 is turned off. At this time, the body diode of the fourth switch 24 does not allow a current to flow from the input terminal side to the output terminal side. In other words, the energy stored in the inductor L is not consumed by the body diode of the second switching element SW2 and the body diode of the fifth switch 25.

[0036] (Effects of this embodiment) (1) In the above embodiment, when the control unit 40 cuts off the electrical connection between the input terminal and the output terminal, the control unit 40 first switches the first switch 21 to the off state and then switches the second switch 22 to the off state. For example, when cutting off electrical continuity between the input terminal and the output terminal due to a short circuit at the output terminal, the first switch 21 is first switched to the off state, so that the battery 50 can be protected from an overcurrent. Then, at least a part of the energy stored in the inductor L and the like constituting the power supply device 10 from when the first switch 21 is switched to the off state until when the second switch 22 is switched to the off state is consumed by the internal resistance and the like of the second switch 22. Therefore, even if the second switch 22 is switched to the off state, a large load due to the action of the above energy is unlikely to be applied to the second switch 22. In addition, ringing is unlikely to occur when the second switch 22 is switched to the off state.

[0037] (2) In the above embodiment, the control unit 40 switches the second switching element SW2 serving as the third switch 23 to the off state after switching the first switch 21 to the off state. Thereafter, the control unit 40 switches the second switch 22 to the off state. At least a part of the energy stored in elements such as the inductor L is consumed by the resistance of the body diode of the second switching element SW2. By switching off the second switch 22 thereafter, the load on the second switch 22 can be further reduced.

[0038] (3) In the above embodiment, the second switch 22 is a bidirectional switch. Then, the control unit 40 switches the fifth switch 25 to the off state, and then switches the fourth switch 24 to the off state. By switching the fifth switch 25 to the off state first, at least a part of the energy stored in the inductor L, etc. is consumed by the resistance of the body diode of the fifth switch 25. Therefore, the load on the entire second switch 22 can be reduced.

[0039] (4) In the above embodiment, the control unit 40 switches the first switch 21 to the OFF state, and then switches the second switching element SW2 and the fifth switch 25 to the OFF state. Thereafter, the control unit 40 switches the fourth switch 24 to the OFF state. As a result, at least a part of the energy stored in elements such as the inductor L is consumed by the resistance of the body diode of the second switching element SW2 and the fifth switch 25. By switching the fourth switch 24 to the OFF state after that, the load on the fourth switch 24 can be reduced.

[0040] (5) In the above embodiment, the time from when the second switching element SW2 and the fifth switch 25 are switched to the OFF state until when the fourth switch 24 is switched to the OFF state is longer than the time from when the first switch 21 is switched to the OFF state until when the second switching element SW2 is switched to the OFF state. This causes a time until the energy stored in elements such as the inductor L is consumed. Therefore, the load on the second switch 22 can be more significantly reduced.

[0041] (6) In the above embodiment, the time from when the second switching element SW2 and the fifth switch 25 are switched to the OFF state to when the fourth switch 24 is switched to the OFF state is 1 millisecond or more and less than 100 milliseconds. If this amount of time is allowed, the energy stored in elements such as the inductor L is mostly consumed. Therefore, the load when the fourth switch 24 is switched to the OFF state can be significantly reduced. Also, even if the above switching control is performed when each output terminal is short-circuited, the impact of the short-circuit current is small so long as the time does not exceed 100 milliseconds.

[0042] (7) In the above embodiment, the first switch 21 is configured by connecting a plurality of bidirectional switches in parallel. In contrast, the second switch 22 is a single bidirectional switch. Therefore, assuming that the same load is applied to each switch, the load applied to each switching element of each switch is larger in the second switch 22. According to the above embodiment, the first switch 21 is switched to the OFF state, and then the second switch 22 is switched to the OFF state, so that a large load is unlikely to be applied to the second switch 22. That is, this is suitable as a circuit configuration to which the switching control is applied. In addition, an element with a relatively small tolerance can be adopted as the switching element constituting the second switch 22. That is, a larger variety of elements can be selected as the switching element constituting the second switch 22.

[0043] <Example of change> The above embodiment and the following modified examples can be implemented in combination with each other to the extent that no technical contradiction occurs.

[0044] The configuration of the power supply device 10 is not limited to the example of the above embodiment as long as it has the first switch 21, the second switch 22, the power conversion circuit 13, and a control unit 40 capable of executing switching control for each switch. The type of power source connected to the input terminal, parameters such as voltage, and the type of load connected to the output terminal may be changed as appropriate depending on the application of the power supply device 10, etc.

[0045] The power source connected to the input terminal does not have to be the battery 50 as long as it is a DC power source. The configuration of the power conversion circuit 13 is not limited to the example of the above embodiment. For example, a configuration in which a plurality of boost converters are connected in parallel may be used. A step-down converter may be used instead of a step-up converter. In these cases, the third switch 23 is not limited to the second switching element SW2 in the above embodiment. The third switch 23 may be a switching element in which the anode terminal of the body diode is connected to the first switch 21.

[0046] The configuration of the first switch 21 and the second switch 22 is not limited to the configuration of the above embodiment as long as they can be switched to an on state or an off state by the control unit 40. For example, they may be one bidirectional switch or a bipolar transistor.

[0047] The control unit 40 only needs to be able to switch at least the first switch 21 and the second switch 22 between an on state and an off state. Furthermore, the control unit 40 is not limited to being configured with one MCU. In other words, the MCU that controls the first switch 21 and the MCU that controls the second switch 22 may be configured separately as different chips.

[0048] In the switching control, it is only necessary for the control unit 40 to be able to switch the second switch 22 to the OFF state after switching at least the first switch 21 to the OFF state. For example, the third switch 23 may be turned off immediately before the first switch 21 is switched off. Also, the third switch 23 may be turned off after the second switch 22 is switched off. Even in these cases, the load on the second switch 22 can be reduced when the second switch 22 is switched off.

[0049] The control unit 40 may switch the fourth switch 24 to the off state, and then switch the fifth switch 25 to the off state, thereby switching the second switch 22 to the off state. For example, the control unit 40 switches the first switch 21 to the OFF state, and then switches the third switch 23 to the OFF state. Next, after a predetermined time has elapsed, the control unit 40 may switch the fourth switch 24 to the OFF state, and then switch the fifth switch 25 to the OFF state. Even in this case, part of the energy stored in the inductor, etc. is consumed by the body diode of the third switch 23. That is, the load on the second switch 22 can be suppressed.

[0050] After switching the second switch 22 to the off state, the control unit 40 may switch the third switch 23 to the off state. For example, in the switching control, after the first switch 21 is switched to the off state, the fifth switch 25 is switched to the off state. Next, after a predetermined time has elapsed, the fourth switch 24 may be switched to the off state, and then the third switch 23 may be switched to the off state. Even in this case, part of the energy stored in the inductor, etc. is consumed by the body diode of the fifth switch 25. That is, the load on the fourth switch 24 and the third switch 23 can be reduced.

[0051] In the switching control, the order of the timing to turn off the third switch 23 and the timing to turn off the fifth switch 25 does not matter. That is, the timings may be approximately simultaneous, or the fifth switch 25 may be turned off before the third switch 23 is turned off. In either case, the energy stored in the inductor L and the like is consumed by the body diodes of each switching element and each switch.

[0052] The time from when the third switch 23 and the fifth switch 25 are switched to the OFF state until when the fourth switch 24 is switched to the OFF state may be shorter than the time from when the first switch 21 is switched to the OFF state until when the third switch 23 and the fifth switch 25 are switched to the OFF state. Even in this case, the load on the second switch 22 can be suppressed by using the switching control.

[0053] The time from when the third switch 23 and the fifth switch 25 are switched to the OFF state until the fourth switch 24 is switched to the OFF state may be less than 1 millisecond or may be 100 milliseconds or more. Even in these cases, the above switching control can reduce the load on the second switch 22. For example, even if a time difference of less than 1 millisecond is provided until the third switch 23 and the fifth switch 25 are switched off, the load on the second switch 22 can be reduced compared to the case where this time is not provided.

[0054] <Additional Notes> The technical ideas that can be derived from the above-described embodiments and modifications will be described below. [1] An input terminal to which a DC power supply can be connected; An output terminal; a power conversion circuit disposed between the input terminal and the output terminal; a first possible switch disposed between the input terminal and the power conversion circuit; a second switch disposed between the power conversion circuit and the output terminal; A control unit that controls the first switch and the second switch; Equipped with The power supply device, wherein, when the control unit cuts off the electrical connection between the input terminal and the output terminal, the control unit switches the first switch to an off state and then switches the second switch to an off state.

[0055] [2] the power conversion circuit includes a third switch having an anode side terminal of a body diode connected to the first switch; The power supply device according to [1], wherein the control unit is capable of controlling the third switch, and when cutting off the electrical connection between the input terminal and the output terminal, switches the third switch to an off state after switching the first switch to an off state and before switching the second switch to an off state.

[0056] [3] The second switch is a fourth switch connected to the power conversion circuit and having a body diode; a fifth switch having a body diode disposed between the fourth switch and the output terminal; A bidirectional switch having the fourth switch and the fifth switch are connected in series such that anode side terminals of body diodes of the fourth switch and the fifth switch are connected to each other, The power supply device according to any one of claims 1 to 2, wherein the control unit switches the fourth switch to an off state after switching the fifth switch to an off state.

[0057] [4] the power conversion circuit includes a third switch having an anode side terminal of a body diode connected to the first switch; The power supply device described in [3], wherein the control unit is capable of controlling the third switch, and when cutting off the electrical connection between the input terminal and the output terminal, after switching the first switch to an off state, switches the third switch and the fifth switch to an off state, and then switches the fourth switch to an off state.

[0058] [5] [4] The power supply device according to claim 4, wherein a time from when the third switch and the fifth switch are switched to an off state to when the fourth switch is switched to an off state is longer than a time from when the first switch is switched to an off state to when the third switch and the fifth switch are switched to an off state.

[0059] [6] The power supply device according to [5], wherein the time from when the third switch and the fifth switch are switched to an off state to when the fourth switch is switched to an off state is greater than or equal to 1 millisecond and less than 100 milliseconds.

[0060] [7] An input terminal to which a DC power supply can be connected; An output terminal; a power conversion circuit disposed between the input terminal and the output terminal; a first possible switch disposed between the input terminal and the power conversion circuit; a second switch disposed between the power conversion circuit and the output terminal; A control unit that controls the first switch and the second switch; The present invention relates to a power supply device comprising: When the electrical connection between the input terminal and the output terminal is interrupted, a program that causes the control unit to execute a process of switching the second switch to an off state after switching the first switch to an off state; [Explanation of symbols]

[0061] 50…Battery 10…Power supply device LA: High potential power line 11A…High potential input terminal 11B: Low potential input terminal 12A…High voltage output terminal 12B: Low potential output terminal 13...Power conversion circuit SW1: First switching element SW2: Second switching element 21…First switch 22…Second switch 23…Third switch 24…4th switch 25…5th switch 40...Control unit PG…Program 60…Load

Claims

1. An input terminal to which a DC power supply can be connected; An output terminal; a power conversion circuit disposed between the input terminal and the output terminal; a first possible switch disposed between the input terminal and the power conversion circuit; a second switch disposed between the power conversion circuit and the output terminal; A control unit that controls the first switch and the second switch; Equipped with When the control unit cuts off the electrical connection between the input terminal and the output terminal, the control unit switches the first switch to an off state and then switches the second switch to an off state. power supply.

2. the power conversion circuit includes a third switch having an anode side terminal of a body diode connected to the first switch; The control unit is capable of controlling the third switch, and when cutting off the electrical connection between the input terminal and the output terminal, switches the third switch to an off state after switching the first switch to an off state and before switching the second switch to an off state.

2. The power supply device of claim 1.

3. The second switch is a fourth switch connected to the power conversion circuit and having a body diode; a fifth switch having a body diode disposed between the fourth switch and the output terminal; A bidirectional switch having the fourth switch and the fifth switch are connected in series such that anode side terminals of body diodes of the fourth switch and the fifth switch are connected to each other, The control unit switches the fifth switch to an off state and then switches the fourth switch to an off state.

2. The power supply device of claim 1.

4. the power conversion circuit includes a third switch having an anode side terminal of a body diode connected to the first switch; The control unit is capable of controlling the third switch, and when cutting off the electrical connection between the input terminal and the output terminal, switches the first switch to an off state, then switches the third switch and the fifth switch to an off state, and then switches the fourth switch to an off state.

4. The power supply device of claim 3.

5. A time period from when the third switch and the fifth switch are switched to an off state until when the fourth switch is switched to an off state is longer than a time period from when the first switch is switched to an off state until when the third switch and the fifth switch are switched to an off state.

5. The power supply device according to claim 4.

6. The time from when the third switch and the fifth switch are switched to an off state to when the fourth switch is switched to an off state is equal to or longer than 1 millisecond and shorter than 100 milliseconds.

6. The power supply device according to claim 5.

7. An input terminal to which a DC power supply can be connected; An output terminal; a power conversion circuit disposed between the input terminal and the output terminal; a first possible switch disposed between the input terminal and the power conversion circuit; a second switch disposed between the power conversion circuit and the output terminal; A control unit that controls the first switch and the second switch; The present invention relates to a power supply device comprising: When the electrical connection between the input terminal and the output terminal is interrupted, The control unit executes a process of switching the first switch to an OFF state and then switching the second switch to an OFF state. program.

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