DC semiconductor circuit breaker and control method for the same

Abstract

To provide a DC semiconductor circuit breaker that can reduce a surge current flowing into a capacitor.SOLUTION: A DC semiconductor circuit breaker (10) includes a semiconductor switch (SWm), a Zener diode (ZD) and a first switch (SW1) connected in series with each other, and a resistive element (R), a capacitor (C), and a second switch (SW2) connected in series with each other and connected in parallel with the Zener diode (ZD) and the first switch (SW1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a DC semiconductor circuit breaker and a method for controlling a DC semiconductor circuit breaker.

Background Art

[0002] A DC circuit breaker using a semiconductor switch, so-called a DC semiconductor circuit breaker, has been proposed. In a DC semiconductor circuit breaker, it is common to provide a configuration for protecting the semiconductor switch from a surge current generated when the DC semiconductor circuit breaker is interrupted.

[0003] Patent Documents 1 and 2 disclose a configuration for preventing destruction of a semiconductor switch due to a surge current generated when a DC semiconductor circuit breaker is interrupted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration disclosed in Patent Document 1, a surge current enters the capacitor of the RC snubber circuit, and the capacitor deteriorates. The configuration disclosed in Patent Document 2 uses a surge absorber that cannot be operated repeatedly.

[0006] One aspect of the present invention aims to realize a DC semiconductor circuit breaker that reduces the inflow of a surge current into a capacitor and can be interrupted repeatedly.

Means for Solving the Problems

[0007] A DC semiconductor circuit breaker according to one aspect of the present invention includes a first input terminal and a second input terminal to which a DC power supply is connected, a first output terminal and a second output terminal to which a DC load is connected, a connection point located between the first input terminal and the first output terminal, a semiconductor switch connected between the first output terminal and the connection point, a Zener diode and a first switch connected in series with each other and connected between the connection point and the second output terminal, and a resistor element, a capacitor, and a second switch connected in series with each other and connected in parallel with the Zener diode and the first switch.

[0008] A control method for a DC semiconductor circuit breaker according to one aspect of the present invention is a control method for a DC semiconductor circuit breaker including a first input terminal and a second input terminal to which a DC power supply is connected, a first output terminal and a second output terminal to which a DC load is connected, a connection point located between the first input terminal and the first output terminal, a semiconductor switch connected between the first output terminal and the connection point, a Zener diode and a first switch connected in series with each other and connected between the connection point and the second output terminal, and a resistor element, a capacitor, and a second switch connected in series with each other and connected in parallel with the Zener diode and the first switch. The method includes a first step of switching the first switch to a conducting state and a second step of switching the semiconductor switch to a non-conducting state. After the first step and the second step, a breaking operation is performed, which includes a third step of switching the second switch to a conducting state and a fourth step of switching the first switch to a non-conducting state.

Advantages of the Invention

[0009] According to one aspect of the present invention, the inflow of surge current into the capacitor can be reduced, and repeated interruption can be achieved.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0011] 〔Embodiment 1〕 Hereinafter, an embodiment of the present invention will be described in detail.

[0012] (Configuration of DC Circuit 1) FIG. 1 is a circuit diagram showing an example of the configuration of a DC circuit 1 according to the present disclosure. The DC circuit 1 includes a DC semiconductor circuit breaker 10, a DC power supply PW, and a DC load LD.

[0013] The DC semiconductor circuit breaker 10 includes a first input terminal I1, a second input terminal I2, a first output terminal O1, and a second output terminal O2. The DC power supply PW is connected to the first input terminal I1 and the second input terminal I2. The DC load LD is connected to the first output terminal O1 and the second output terminal O2. The DC semiconductor circuit breaker 10 is an electrical device that outputs the current input from the DC power supply PW, which is the primary circuit, to the DC load LD, which is the secondary circuit. Further, the DC semiconductor circuit breaker 10 determines the situation of the DC load LD, and when a current equal to or greater than the rated current of the DC semiconductor circuit breaker 10 is detected, it performs an operation of blocking the current from the primary circuit without outputting it to the secondary circuit.

[0014] The DC power supply PW outputs a DC power supply voltage E between the first input terminal I1 and the second input terminal I2. Also, the DC load LD consumes the DC power supplied from the first output terminal O1 and the second output terminal O2.

[0015] (Configuration of the DC semiconductor circuit breaker 10) The DC semiconductor circuit breaker 10 includes a semiconductor switch SWm, a first switch SW1, a second switch SW2, a third switch SW3, a resistance element R, a capacitor C, a Zener diode ZD, a freewheeling diode RD, a current detection unit CD, a voltage detection unit VD, and a control unit CN. The DC semiconductor circuit breaker 10 includes the first input terminal I1 and the second input terminal I2 as input terminals and is connected to the primary circuit. Also, the DC semiconductor circuit breaker 10 includes the first output terminal O1 and the second output terminal O2 as output terminals and is connected to the secondary circuit.

[0016] The semiconductor switch SWm is connected between the first input terminal I1 and the first output terminal O1. The semiconductor switch SWm is a transistor having no mechanical contacts. The primary side of the semiconductor switch SWm is connected to the first input terminal I1. The connection point (node) of the primary side of the semiconductor switch SWm is referred to as a connection point JP. That is, the connection point JP is located between the first input terminal I1 and the semiconductor switch SWm. The current detection unit CD (current sensor) is arranged between the first input terminal I1 and the connection point JP and measures the current value Iin of the input current input from the first input terminal I1.

[0017] A Zener diode ZD and a first switch SW1 connected in series with each other are connected between the connection point JP and the second output terminal O2. A resistance element R, a capacitor C, and a second switch SW2 connected in series with each other are connected in parallel with the Zener diode ZD and the first switch SW1 between the connection point JP and the second output terminal O2. A freewheeling diode RD is connected between the first output terminal O1 and the second output terminal O2.

[0018] The Zener diode ZD is arranged such that its cathode is connected to the connection point JP side and its anode is connected to the second output terminal O2 side. The first switch SW1 and the second switch SW2 may each be a relay or an electromagnetic contactor having mechanical contacts, or a transistor having no mechanical contacts. The freewheeling diode RD is arranged such that its cathode is connected to the first output terminal O1 side and its anode is connected to the second output terminal O2 side.

[0019] A third switch SW3 is connected in series with the resistor element R and the second switch SW2 and in parallel with the capacitor C. The third switch SW3 may be a relay or an electromagnetic contactor having mechanical contacts, or a transistor having no mechanical contacts.

[0020] A voltage detection unit VD (voltage sensor) for measuring the voltage value Vzd applied to the Zener diode ZD is connected in parallel with the Zener diode ZD.

[0021] (Configuration of the control unit CN) FIG. 2 is a block diagram showing an example of the configuration of the control unit CN shown in FIG. 1. The control unit CN includes an acquisition unit 11, a storage unit 12, a processing unit 13, a semiconductor driver unit 14, a first driver unit 15, a second driver unit 16, and a third driver unit 17.

[0022] The acquisition unit 11 is connected to the current detection unit CD and the voltage detection unit VD. The acquisition unit 11 acquires the current value Iin measured by the current detection unit CD and the voltage value Vzd measured by the detection unit VD. The storage unit 12 is connected to the acquisition unit 11. The storage unit 12 stores the current value Iin and the voltage value Vzd acquired by the acquisition unit 11. The processing unit 13 is connected to the storage unit 12 and executes various processes.

[0023] The processing unit 13 includes, for example, a current determination unit 131, an estimation unit 132, an energy determination unit 133, a semiconductor control unit 134, a first control unit 135, a second control unit 136, and a third control unit 137. The current determination unit 131 determines the current value Iin. The estimation unit 132 estimates the interruption energy Ej. The energy determination unit 133 determines the interruption energy Ej. The semiconductor control unit 134 controls the semiconductor switch SWm based on the determination results of the current determination unit 131 and / or the energy determination unit 133. The first control unit 135 controls the first switch SW1 based on the determination results. The second control unit 136 controls the second switch SW2 based on the determination results. The third control unit 137 controls the third switch SW3 based on the determination results.

[0024] A semiconductor driver unit 14, a first driver unit 15, a second driver unit 16, and a third driver unit 17 are respectively connected to the processing unit 13. The semiconductor driver unit 14, the first driver unit 15, the second driver unit 16, and the third driver unit 17 respectively switch the conduction state / non-conduction state of the semiconductor switch SWm, the first switch SW1, the second switch SW2, and the third switch SW3.

[0025] (Operation of the DC semiconductor circuit breaker 10) FIG. 3 is a flowchart showing an example of the operation of the DC semiconductor circuit breaker 10 shown in FIG. 1. FIG. 4 is a timing chart showing an example of the operation of the DC semiconductor circuit breaker 10 shown in FIG. 1. Hereinafter, a case where the DC semiconductor circuit breaker 10 that conducts the primary circuit and the secondary circuit interrupts the primary circuit and the secondary circuit will be described. The DC semiconductor circuit breaker 10 that conducts the primary circuit and the secondary circuit is in the on state, the semiconductor switch SWm is in the conduction state, and the first switch SW1, the second switch SW2, and the third switch SW3 are in the non-conduction state.

[0026] In step S11, the current determination unit 131 of the control unit CN compares the current value Iin with the first current threshold Ith1. The first threshold Ith1 is the rated current of the DC semiconductor circuit breaker 10. Between time t0 and time t2, Iin ≤ Ith1, and the current determination unit 131 determines that no overcurrent is detected and repeats step S11. At time t1, the secondary circuit shorts and the current value Iin increases. Then, at time t2, Iin > Ith1, and the current determination unit 131 determines that an overcurrent has been detected and proceeds to step S12.

[0027] In step S12 (the first step), the control unit CN switches the first switch SW1 to the conducting state. In step S13 (the second step), the control unit CN switches the semiconductor switch SWm to the non-conducting state. Steps S12 and S13 may be executed in this order or simultaneously.

[0028] In step S14, the estimation unit 132 of the control unit CN estimates the interruption energy Ej, that is, the electrical energy that has flowed into the Zener diode ZD from time t2 to the current point in time. In step S14, the current value of the current flowing through the Zener diode ZD is the same as the current value Iin. The estimation unit 132 may read the current value Iin and the voltage value Vzd from the storage unit 12 and calculate the interruption energy Ej using integration in numerical calculation methods.

[0029] In step S15, the current determination unit 131 of the control unit CN compares the current value Iin with the second current threshold Ith2. The second threshold Ith2 is smaller than the first threshold Ith1 and is approximately close to 0. Between time t2 and time t3, Iin ≥ Ith2, and the current determination unit 131 determines that interruption cannot be completed and proceeds to step S16.

[0030] In step S16, the energy determination unit 133 of the control unit CN compares the interruption energy Ej with the allowable energy value Eth. Between time t2 and time t3, Ej ≦ Eth, and the energy determination unit 133 determines that the interruption energy Ej does not exceed the allowable value Eth, and returns to step S14.

[0031] Then, at time t3, Iin < Ith2, and in step S15, the current determination unit 131 determines that interruption can be completed, and proceeds to step S17. In step S17, the control unit CN switches the first switch SW1 to the non-conductive state. As a result, the DC semiconductor circuit breaker 10 enters a cut-off state in which the cut-off between the primary circuit and the secondary circuit is completed. In the cut-off state, all of the semiconductor switch SWm, the first switch SW1, the second switch SW2, and the third switch SW3 are in the non-conductive state.

[0032] Figure 5 is a timing chart of another example of the operation of the DC semiconductor circuit breaker 10 shown in Figure 1. In the first period d1 in which the surge current passes through the Zener diode ZD, the first switch SW1 is in the conductive state and the second switch SW2 is in the non-conductive state. In the first period d1, the third switch SW3 may be in the conductive state or the non-conductive state. At time t4, since Iin ≧ Ith2 and Ej > Eth, the process proceeds from step S15 to step S16. In step S16, the energy determination unit 133 determines that the interruption energy Ej exceeds the allowable value Eth, and proceeds to step S18.

[0033] In step S18, the control unit CN switches the third switch SW3 to the conducting state. In step S19 (the third step), the control unit CN switches the second switch SW2 to the conducting state. In step S20 (the fourth step), the control unit CN switches the first switch SW1 to the non-conducting state. Steps S18 and S19 may be executed in this order or simultaneously. Steps S19 and S20 may be executed in this order or simultaneously. As a result of step S19, current flows into the snubber circuit SN including the resistor element R and the capacitor C.

[0034] During the second period d2 in which the remaining surge current passes through the resistor element R, the first switch SW1 is in the conducting state and the second switch SW2 is in the non-conducting state. During the third period d3 in which the current passes through the third switch SW3 within the second period d2, the first switch SW1 is in the non-conducting state, the second switch SW2 is in the conducting state, and the third switch SW3 is in the conducting state. During the fourth period d4 in which the current flows into the capacitor C within the second period d2, the first switch SW1 is in the non-conducting state, the second switch SW2 is in the conducting state, and the third switch SW3 is in the non-conducting state.

[0035] In step S21, the current determination unit 131 of the control unit CN compares the current value Iin with the third current threshold Ith3. The third threshold Ith3 is smaller than the first threshold Ith1 and larger than the second threshold Ith2. Between time t4 and time t5, Iin≧Ith3, and the current determination unit 131 repeats step S21. At time t5, Iin<Ith3, and the process proceeds to step S22.

[0036] In step S22, the control unit CN switches the third switch SW3 to the non-conductive state. In step S23, the current determination unit 131 of the control unit CN compares the current value Iin with the second current threshold Ith2. Between time t5 and time t6, Iin ≥ Ith2, and the current determination unit 131 determines that interruption cannot be completed, and step S23 is repeated. Then, at time t6, Iin < Ith2, and the current determination unit 131 determines that interruption can be completed, and the process proceeds to step S24. In step S24, the control unit CN switches the second switch SW2 to the non-conductive state. As a result, the DC semiconductor circuit breaker 10 enters a cut-off state in which the interruption between the primary circuit and the secondary circuit is completed.

[0037] Figure 6 is a timing chart showing another example of the operation of the DC semiconductor circuit breaker 10 shown in FIG. 1. In FIG. 6, the switching is not synchronized. At time t21, the current determination unit 131 in step S11 determines that an overcurrent has been detected, and the control unit CN in step S12 switches the first switch SW1 to the conductive state. Subsequently, at time t22, the control unit CN in step S13 switches the semiconductor switch SWm to the non-conductive state.

[0038] Thereafter, at time t41, the energy determination unit 133 in step S16 determines that the interruption energy Ej exceeds the allowable value Eth, and the control unit CN in step S18 switches the third switch SW3 to the conductive state. Subsequently, at time t42, the control unit CN in step S19 switches the second switch SW2 to the conductive state, and at time t43, the control unit CN in step S20 switches the first switch SW1 to the non-conductive state.

[0039] (Function and Effect of DC Semiconductor Circuit Breaker 10) In the DC semiconductor circuit breaker 10, when performing an operation to cut off the primary circuit and the secondary circuit, first, the first switch SW1 is switched to the conducting state, and at the same time or next, the semiconductor switch SWm is switched to the non-conducting state. As a result, the peak portion of the surge current generated by the interruption of the semiconductor switch SWm passes through the Zener diode ZD. Therefore, the inflow of the surge current into the capacitor C can be reduced.

[0040] When the interruption energy Ej applied to the Zener diode ZD exceeds the allowable value Eth, the remaining surge current flows into the snubber circuit SN including the resistor element R and the capacitor C. Therefore, the deterioration of the Zener diode ZD can be reduced, and the DC semiconductor circuit breaker 10 can repeatedly cut off the primary circuit and the secondary circuit.

[0041] By allowing the current flowing into the snubber circuit SN to pass through the resistor element R and the third switch SW3, the inflow of current into the capacitor C can be further reduced.

[0042] 〔Embodiment 2〕 Another embodiment of the present invention will be described below. For the sake of convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

[0043] FIG. 7 is a circuit diagram showing an example of the configuration of the DC circuit 1a according to the present disclosure. The DC semiconductor circuit breaker 10a according to the present embodiment does not include a voltage detection unit. The current-voltage characteristics of the Zener diode ZD measured in advance are stored in the storage unit 12, and the estimation unit 132 uses, as the voltage value Vzd applied to the Zener diode ZD, a value obtained by applying the current value Iin to the current-voltage characteristics of the Zener diode ZD. Alternatively, the breakdown voltage of the Zener diode ZD is stored in the storage unit 12, and the estimation unit 132 uses the breakdown voltage of the Zener diode ZD as the voltage value Vzd.

[0044] The third switch SW3 according to this embodiment is connected in series to the resistance element R and in parallel to the capacitor C and the third switch SW. Therefore, in the first period d1 in which the surge current passes through the Zener diode ZD, both the second switch SW2 and the third switch SW3 are in the non-conducting state. In the third period d3 in which the current passes through the resistance element R and the third switch SW3, the second switch SW2 may be in the conducting state or the non-conducting state, and the third switch SW3 is in the conducting state. In the fourth period d4, the second switch SW2 is in the conducting state and the third switch SW3 is in the non-conducting state.

[0045] 〔Embodiment 3〕 Still another embodiment of the present invention will be described below.

[0046] FIG. 8 is a circuit diagram showing an example of the configuration of the DC circuit 1b according to the present disclosure. The DC semiconductor circuit breaker 10b according to this embodiment is different from the DC semiconductor circuit breaker 10 of the first embodiment in that it does not include a third switch. The operations of the semiconductor switch SWm, the first switch SW1, and the second switch SW2 are the same as those shown in FIGS. 5 and 6. Even in this case, since the surge current generated by the interruption of the semiconductor switch SWm is attenuated by the Zener diode ZD first, the inflow of the surge current into the capacitor C can be reduced.

[0047] 〔Example of Realization by Software〕 The functions of the DC semiconductor circuit breakers 10, 10a, 10b (hereinafter referred to as "devices") can be realized by a program for causing a computer to function as the device and a program for causing a computer to function as each control block (particularly each part included in the control unit CN) of the device.

[0048] In this case, as hardware for executing the above program, the apparatus includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory). By executing the above program with this control device and storage device, each function described in each of the above embodiments is realized.

[0049] The above program may be recorded on one or more computer-readable recording media, rather than temporarily. This recording medium may or may not be included in the above apparatus. In the latter case, the above program may be supplied to the above apparatus via any wired or wireless transmission medium.

[0050] Also, part or all of the functions of the above control blocks can also be realized by a logic circuit. For example, an integrated circuit in which a logic circuit functioning as each of the above control blocks is formed is also included in the scope of the present invention. In addition to this, for example, it is also possible to realize the functions of the above control blocks by a quantum computer.

[0051] 〔Summary〕 In order to solve the above problems, a DC semiconductor circuit breaker according to aspect 1 of the present invention includes a first input terminal (I1) and a second input terminal (I2) to which a DC power supply (PW) is connected, a first output terminal (O1) and a second output terminal (O2) to which a DC load (LD) is connected, a connection point (JP) located between the first input terminal and the first output terminal, a semiconductor switch (SWm) connected between the first output terminal and the connection point, a Zener diode (ZD) and a first switch (SW1) connected in series with each other and connected between the connection point and the second output terminal, and a resistor element (R), a capacitor (C), and a second switch (SW2) connected in series with each other and connected in parallel to the Zener diode and the first switch.

[0052] According to the above configuration, in the DC semiconductor circuit breaker, the inflow of surge current into the capacitor can be reduced, and repeated interruption can be achieved.

[0053] In the DC semiconductor circuit breaker according to Embodiment 2 of the present invention, in the above Embodiment 1, after switching the semiconductor switch to the non-conducting state, a first period (d1) in which the first switch is in the conducting state and the second switch is in the non-conducting state, and a second period (d2) after the first period, in which the first switch is in the non-conducting state and the second switch is in the conducting state, may be provided to perform a breaking operation.

[0054] According to the above configuration, in the first period, the peak portion of the surge current generated by the switching of the semiconductor switch passes through the Zener diode. In the second period, the remainder of the surge current passes through the resistive element and flows into the capacitor. By these means, the inflow of the surge current into the capacitor can be reduced, and repeated breaking can be achieved.

[0055] The DC semiconductor circuit breaker according to Embodiment 3 of the present invention may include, in the above Embodiment 1, a third switch (SW3) connected in series to the resistive element and the second switch and in parallel to the capacitor.

[0056] According to the above configuration, by the current passing through the resistive element R also passing through the third switch, the inflow of the surge current into the capacitor can be further reduced.

[0057] In the DC semiconductor circuit breaker according to Embodiment 4 of the present invention, in the above Embodiment 3, after switching the semiconductor switch to the non-conducting state, a first period in which the first switch is in the conducting state and the second switch is in the non-conducting state, a third period (d3) after the first period, in which the first switch is in the non-conducting state, the second switch is in the conducting state, and the third switch is in the conducting state, and a fourth period (d4) after the third period, in which the first switch is in the non-conducting state, the second switch is in the conducting state, and the third switch is in the non-conducting state, may be provided to perform a breaking operation.

[0058] According to the above configuration, in the first period, the peak portion of the surge current generated by the switching of the semiconductor switch passes through the Zener diode. The remainder of the surge current passes through the resistance element and the third switch in the third period, and in the fourth period, it passes through the resistance element and flows into the capacitor. By these means, the inflow of the surge current into the capacitor can be reduced and repeatedly interrupted.

[0059] The DC semiconductor circuit breaker (10b) according to aspect 5 of the present invention may, in the aspect 1, include a third switch (SW3) connected in series to the resistance element and in parallel to the capacitor and the second switch.

[0060] According to the above configuration, by the current passing through the resistance element R passing through the third switch, the inflow of the surge current into the capacitor can be further reduced.

[0061] The DC semiconductor circuit breaker according to aspect 6 of the present invention may perform a breaking operation by providing, in the aspect 5, a first period in which, after the semiconductor switch is switched to the non-conducting state, the first switch is in the conducting state, the second switch is in the non-conducting state, and the third switch is in the non-conducting state; a third period after the first period in which the first switch is in the non-conducting state and the third switch is in the conducting state; and a fourth period after the third period in which the first switch is in the non-conducting state, the second switch is in the conducting state, and the third switch is in the non-conducting state.

[0062] According to the above configuration, in the first period, the peak portion of the surge current generated by the switching of the semiconductor switch passes through the Zener diode. The remainder of the surge current passes through the resistance element and the third switch in the third period, and in the fourth period, it passes through the resistance element R and flows into the capacitor C. By these means, the inflow of the surge current into the capacitor can be reduced and repeatedly interrupted.

[0063] In the case of Aspect 7 of the present invention, the DC semiconductor circuit breaker may include a control unit (CN) that switches the first switch to a non-conductive state according to the energy (Ej) flowing into the Zener diode due to the current flowing through the Zener diode in Aspect 2, 4, or 6.

[0064] According to the above configuration, it is possible to stop the energy inflow into the Zener diode before the energy flowing into the Zener diode deteriorates or destroys the Zener diode.

[0065] In the case of Aspect 8 of the present invention, in Aspect 7, the control unit may include an acquisition unit (11) that acquires the current value (Iin) flowing through the Zener diode, and an estimation unit (132) that estimates the energy flowing into the Zener diode based on the current value.

[0066] According to the above configuration, it is possible to estimate the energy flowing into the Zener diode from the current value flowing through the Zener diode.

[0067] In the case of Aspect 9 of the present invention, in Aspect 8, the acquisition unit may acquire the voltage value (Vzd) applied to the Zener diode, and the estimation unit may estimate the energy flowing into the Zener diode based on the current value and the voltage value.

[0068] According to the above configuration, it is possible to estimate the energy flowing into the Zener diode from the current value flowing through the Zener diode and the voltage value applied to the Zener diode.

[0069] The control method of the DC semiconductor circuit breaker according to aspect 10 of the present invention includes a first input terminal and a second input terminal to which a DC power supply is connected, a first output terminal and a second output terminal to which a DC load is connected, a connection point located between the first input terminal and the first output terminal, a semiconductor switch connected between the first output terminal and the connection point, a Zener diode and a first switch connected in series with each other and connected between the connection point and the second output terminal, and a resistor element, a capacitor, and a second switch connected in series with each other and connected in parallel to the Zener diode and the first switch. The control method of the DC semiconductor circuit breaker includes a first step of switching the first switch to a conductive state and a second step of switching the semiconductor switch to a non-conductive state. After the first step and the second step, a breaking operation including a third step of switching the second switch to a conductive state and a fourth step of switching the first switch to a non-conductive state is performed.

[0070] 〔Supplementary Notes〕 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Explanation of Reference Numerals

[0071] 1, 1a, 1b DC circuit 10, 10a, 10b DC semiconductor circuit breaker 11 Acquisition unit 12 Storage unit 13 Processing unit 131 Current determination unit 132 Estimation unit 133 Energy determination unit C Capacitor CD Current detection unit CN Control unit I1 First input terminal I2 Second input terminal JP Connection point O1 First output terminal O2 Second Output Terminal R Resistor Element RD Flyback Diode SN Snubber Circuit SW1 First Switch SW2 Second Switch SW3 Third Switch SWm Semiconductor Switch VD Voltage Detection Unit ZD Zener Diode

Claims

1. a first input terminal and a second input terminal to which a DC power supply is connected, a first output terminal and a second output terminal to which a DC load is connected, a connection point located between the first input terminal and the first output terminal, a semiconductor switch connected between the first output terminal and the connection point, a Zener diode and a first switch connected in series with each other and connected between the connection point and the second output terminal, a resistor element, a capacitor, and a second switch connected in series with each other and connected in parallel with the Zener diode and the first switch, a DC semiconductor circuit breaker.

2. after switching the semiconductor switch to a non-conducting state, a first period in which the first switch is in a conducting state and the second switch is in a non-conducting state, a second period after the first period, in which the first switch is in a non-conducting state and the second switch is in a conducting state, By providing, a DC semiconductor circuit breaker according to claim 1 that performs a breaking operation.

3. The DC semiconductor circuit breaker according to claim 1, further comprising a third switch connected in series with the resistor element and the second switch and in parallel with the capacitor.

4. after switching the semiconductor switch to a non-conducting state, a first period in which the first switch is in a conducting state and the second switch is in a non-conducting state, a third period after the first period, in which the first switch is in a non-conducting state, the second switch is in a conducting state, and the third switch is in a conducting state, a fourth period after the third period, in which the first switch is in a non-conducting state, the second switch is in a conducting state, and the third switch is in a non-conducting state, The DC semiconductor circuit breaker according to claim 3, which performs a cutoff operation by providing

5. The DC semiconductor circuit breaker according to claim 1, further comprising a third switch connected in series to the resistor element and in parallel to the capacitor and the second switch.

6. After switching the semiconductor switch to the non-conducting state, a first period in which the first switch is in the conducting state, the second switch is in the non-conducting state, and the third switch is in the non-conducting state; a third period after the first period, in which the first switch is in the non-conducting state and the third switch is in the conducting state; a fourth period after the third period, in which the first switch is in the non-conducting state, the second switch is in the conducting state, and the third switch is in the non-conducting state; The DC semiconductor circuit breaker according to claim 5, which performs a cutoff operation by providing

7. The DC semiconductor circuit breaker according to claim 2, 4, or 6, further comprising a control unit configured to switch the first switch to the non-conducting state according to the energy flowing into the Zener diode according to the current flowing through the Zener diode.

8. The control unit includes an acquisition unit configured to acquire a current value flowing through the Zener diode, and an estimation unit configured to estimate the energy flowing into the Zener diode based on the current value. The DC semiconductor circuit breaker according to claim 7.

9. The acquisition unit acquires a voltage value applied to the Zener diode, and the estimation unit estimates the energy flowing into the Zener diode based on the current value and the voltage value. The DC semiconductor circuit breaker according to claim 8.

10. a first input terminal and a second input terminal to which a DC power supply is connected, and A first output terminal and a second output terminal to which a DC load is connected, A connection point located between the first input terminal and the first output terminal, A semiconductor switch connected between the first output terminal and the connection point, A Zener diode and a first switch connected in series with each other and connected between the connection point and the second output terminal, A control method for a DC semiconductor circuit breaker, comprising a resistor element, a capacitor, and a second switch connected in series with each other and connected in parallel to the Zener diode and the first switch, A first step of switching the first switch to a conductive state, A second step of switching the semiconductor switch to a non-conductive state, After the first step and the second step, A third step of switching the second switch to a conductive state, A control method for a DC semiconductor circuit breaker that performs a breaking operation including a fourth step of switching the first switch to a non-conductive state.

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