JP2012004870A - Breaking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To break a current without using any snubber circuit and without damaging a semiconductor breaker.SOLUTION: When a current value detected by a current detection section 13 reaches a predetermined current value, a control section 11 determines that the short circuit or an overcurrent occurs, and controls a semiconductor breaker 12 to start breaking the current. A current flowing to a positive electrode line 51 is branched at a side of a DC power source 80 rather than at the semiconductor breaker 12 so as to prevent the semiconductor breaker 12 from being broken. Furthermore, even after the semiconductor breaker 12 breaks the current, an electrical connection state of the semiconductor breaker 12 is temporarily switched from off to on so as to discharge electric charges charged in a capacitor 14, thereby there is no problem even if capacitance of the capacitor 14 is small.

Description

  The present invention relates to a breaker that protects a circuit when a short circuit occurs.

  In a power supply circuit having a DC power supply and a load fed from the DC power supply via a power supply line, a circuit breaker that cuts off the current is connected between the DC power supply and the load in order to protect the circuit when a short circuit occurs. It is provided in between. Note that the short circuit includes, for example, a ground fault. As the circuit breaker, a fuse, a circuit breaker using a semiconductor, a circuit breaker, or the like is used.

  When a short circuit occurs in a power supply circuit using a circuit breaker using a semiconductor, current interruption is started by a switching element composed of a collector and an emitter. At this time, an electromotive force according to the time change of the current flowing from the DC power supply and the inductance of the power feeding circuit is applied to the semiconductor.

  As a result, the voltage value between the collector and the emitter of the semiconductor suddenly increases, and the semiconductor may be damaged. Hereinafter, the circuit breaker using a semiconductor is referred to as “semiconductor circuit breaker”, and the voltage value between the collector and the emitter is referred to as “voltage value across the semiconductor circuit breaker”.

  In order to avoid damage to the semiconductor, a power supply circuit using a semiconductor circuit breaker generally includes a snubber circuit. For example, Non-Patent Document 1 discloses a technique for suppressing a rapid increase in the voltage value across the semiconductor circuit breaker by the snubber circuit.

  FIG. 12 is a diagram illustrating an example of a power feeding circuit using a semiconductor circuit breaker.

  The power supply circuit shown in FIG. 12 includes a DC power supply 80, a cutoff device 100, and a load 90.

  The circuit breaker 100 includes a control unit 11, a semiconductor circuit breaker 12, a current detection unit 13, and a snubber circuit 101.

  In the snubber circuit 101, normally, as shown in FIG. 12, a resistor and a capacitor are connected in series, and the semiconductor circuit breaker 12 and the snubber circuit 101 are connected in parallel.

  In the power supply circuit shown in FIG. 12, the current value of the current flowing through the positive line 51 is detected by the current detection unit 13. When the detected current value reaches a predetermined current value, the current detection unit 13 outputs a signal to the control unit 11. And the control part 11 will start interruption | blocking of the electric current which flows into the positive electrode line 51 by setting the semiconductor circuit breaker 12 in the OFF state, if the signal output from the electric current detection part 13 is received.

  When the semiconductor circuit breaker 12 starts to cut off the current, the current is commutated to the snubber circuit 101. Thereby, the rapid rise of the voltage value between the both ends of the semiconductor circuit breaker 12 is suppressed, and it can avoid that a semiconductor is damaged.

http://www.fujielectric.co.jp/fdt/scd/technical/application/

  As described above, the use of the snubber circuit can avoid damage to the semiconductor circuit breaker.

  However, when a snubber circuit is used, the breaking device becomes larger by the amount of the snubber circuit. For example, when it is necessary to cut off the current flowing through both the positive and negative lines, a semiconductor breaker and a snubber circuit must be provided on both the positive line and the negative line. Absent. In this case, there is a problem that a space for installing the shut-off device increases.

  Further, when the snubber circuit is used, a current flows through the short-circuit system in order to charge the capacitor of the snubber circuit even after the interruption of the current flowing through the semiconductor is completed. Therefore, when the current output from the DC power supply is branched into a plurality of power supply systems by the current distribution device and supplied to the load, the voltage fluctuation generated by cutting off the current in the power supply system where the short circuit occurred There is a problem in that it propagates to a power supply system where no occurrence occurs.

  In addition, a method is conceivable in which a capacitor is inserted between the positive electrode line and the negative electrode line on the DC power supply 80 side so that the current on the power supply side flows through this capacitor after the breaking operation of the semiconductor circuit breaker. If this is done, the voltage of the capacitor rises after being cut off, so it is necessary to increase the capacitor capacity so as to satisfy a predetermined withstand voltage.

  Then, an object of this invention is to provide the interruption | blocking apparatus which can implement | achieve interruption | blocking of an electric current, without damaging a semiconductor circuit breaker without using a snubber circuit in view of said subject.

In order to achieve the above object, the interrupting device of the present invention is an interrupting device provided between a load fed from a DC power source via a feeder line and the DC power source,
A current detector that is connected to a first connection point on the power supply line and detects a current value of a current flowing through the first connection point;
A semiconductor circuit breaker that is connected to a second connection point on the feeder line and starts to cut off a current flowing through the second connection point when a current value detected by the current detection unit reaches a predetermined current value. When,
When the current flowing through the power supply line is branched and electrical energy is accumulated by the branched current, and the current flowing through the power supply line continues to increase, the stored electrical energy is upstream of the first connection point. When the semiconductor breaker starts to cut off the current as current, and the semiconductor circuit breaker starts to cut off the current, the electric path connecting the positive electrode line and the negative electrode line constituting the power supply line on the load side from the second connection point An electromotive force suppressing unit that causes a current to flow through the electric circuit according to an electromotive force generated by the start of the interruption,
The electromotive force suppression unit is
When the semiconductor circuit breaker is interrupting current, the semiconductor circuit breaker is temporarily energized, and the stored electrical energy is output as current to the feeder line.

  Since the present invention is configured as described above, the current flowing from the DC power source through the feeder line is suppressed when the semiconductor circuit breaker starts interrupting the current after the occurrence of the short circuit. Thereby, the electromotive force based on the inductance of the feeder line between the DC power source and the semiconductor circuit breaker is suppressed.

  Further, when the semiconductor breaker starts to cut off the current, the electromotive force based on the inductance of the feeder line from the semiconductor breaker to the load is not applied between both ends of the semiconductor breaker.

  In addition, even when a capacitor is inserted between the positive and negative electrodes on the DC power supply side, the electrical connection state of the semiconductor circuit breaker is once switched off and then switched on again to charge the capacitor. The generated charge is discharged. As a result, the voltage of the capacitor can be lowered without being raised after being cut off, so that the capacitor capacity can be greatly reduced.

  Moreover, the space for installing the shut-off device can be reduced as compared with the case where a snubber circuit is used. In particular, even when the semiconductor circuit breakers are provided on both the positive electrode line and the negative electrode line, it is not necessary to use the electromotive force suppressing unit for each semiconductor circuit breaker, so that the space saving of the circuit breaker can be realized.

  In addition, it is possible to suppress voltage fluctuations propagating to a power feeding system in which a short circuit has not occurred when current is interrupted, compared to when a snubber circuit is used.

It is a figure which shows the structure of 1st Embodiment of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure which shows an example of the simulation result which measured the voltage value between the both ends of the semiconductor circuit breaker at the time of interruption | blocking of an electric current in the case of the circuit breaker shown in FIG. 1, and the case where a semiconductor circuit breaker and a snubber circuit are used. (A) is a figure which shows the case of the circuit breaker shown in FIG. 1, (b) is a figure which shows the case where a semiconductor circuit breaker and a snubber circuit are used. It is a figure which shows an example of the simulation result which measured the voltage fluctuation which propagates to the electric power feeding system which has not generate | occur | produced a short circuit in the case where the circuit breaker shown in FIG. 1 is applied, and the case where a semiconductor circuit breaker and a snubber circuit are applied. FIG. 2A is a diagram showing a case where the circuit breaker shown in FIG. 1 is applied, and FIG. 2B is a diagram showing a case where a semiconductor circuit breaker and a snubber circuit are applied. It is a flowchart which shows the flow of operation | movement (controlling the semiconductor circuit breaker 12 by time) of the control part 11 of the circuit breaker shown in FIG. It is a flowchart which shows the operation | movement flow (The semiconductor circuit breaker 12 is controlled by the collector-emitter voltage of the semiconductor circuit breaker 12) of the control part 11 of the circuit breaker shown in FIG. It is a figure which shows the structure of 2nd Embodiment of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure which shows the structure of 3rd Embodiment of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure which shows the structure of 4th Embodiment of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure which shows an example of a structure at the time of providing further the diode in the interruption | blocking apparatus shown in FIG. It is a figure which shows the structure of the 1st modification of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure which shows the structure of the 2nd modification of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure which shows an example of the conventional electric power feeding circuit using a semiconductor circuit breaker.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In each drawing referred to in the following description, components equivalent to those in the other drawings are denoted by the same reference numerals.

(First embodiment)
FIG. 1 is a diagram showing a configuration of a first embodiment of a power feeding circuit to which a blocking device of the present invention is applied.

  As shown in FIG. 1, the power supply circuit of the present embodiment includes a cutoff device 10, a DC power supply 80, and a load 90.

  In addition, the interrupting device 10, the DC power supply 80, and the load 90 are connected by a power supply line including a positive electrode line 51 and a negative electrode line 52. Then, when a current flows from the DC power supply 80 through the power supply line, power is supplied to the load 90.

  The interruption device 10 is provided between the DC power supply 80 and the load 90, and includes a control unit 11, a semiconductor circuit breaker 12, a current detection unit 13, a capacitor 14 and a diode 15 which are electromotive force suppression units. I have.

  The current detection unit 13 is connected to a first connection point on the power supply line, and detects a current value of a current flowing through the first connection point. Then, the current detection unit 13 outputs a signal to the control unit 11 when the detected current value reaches a predetermined current value.

  When the control unit 11 receives the signal output from the current detection unit 13, the control unit 11 switches the semiconductor circuit breaker 12 from the on state to the off state.

  The semiconductor circuit breaker 12 is connected to a second connection point on the power supply line, and is switched between an on state and an off state by the control unit 11. The semiconductor circuit breaker 12 starts cutting off the current flowing through the second connection point by being switched from the on state to the off state.

  The capacitor 14 is connected to the positive electrode line 51 and the negative electrode line 52 on the DC power supply 80 side from the first and second connection points. A current flowing through the positive electrode line 51 is branched and flows into the capacitor 14. The capacitor 14 is charged by the flowing current.

  The diode 15 is connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side of the second connection point, and allows a current in the direction from the negative electrode line 52 to the positive electrode line 51 to pass therethrough.

  Below, operation | movement of the interruption | blocking apparatus 10 in the electric power feeding circuit comprised as mentioned above is demonstrated.

  First, a case where a short circuit has not occurred in the power feeding circuit shown in FIG. 1 will be described.

  When no short circuit occurs in the power supply circuit shown in FIG. 1, the current flowing from the DC power supply 80 via the power supply line flows not only to the load 90 but also to the capacitor 14, and the capacitor 14 is charged. It becomes a state. Further, since a reverse voltage is always applied to the diode 15, no current flows through the diode 15. Therefore, the interrupting device 10 operates in the same manner as when the capacitor 14 and the diode 15 are not provided.

  Next, a case where a short circuit occurs in the power feeding circuit illustrated in FIG. 1 will be described.

  When a short circuit occurs in the power supply circuit shown in FIG. 1, the current flowing from the DC power supply 80 through the power supply line increases. Further, a current also flows from the capacitor 14 to the power feeding circuit, and increases with time. When the current value of the current flowing through the first connection point reaches a predetermined current value, the current detection unit 13 outputs a signal to the control unit 11.

  The control unit 11 that receives the signal output from the current detection unit 13 switches the semiconductor circuit breaker 12 from the on state to the off state. Thereby, the semiconductor circuit breaker 12 starts interruption | blocking of an electric current.

  When the semiconductor circuit breaker 12 starts interrupting the current, the current flowing through the semiconductor circuit breaker 12 decreases, and the current flowing through the power supply 80 and the feeder line of the circuit breaker flows through the capacitor 14. When the capacitor 14 is charged with current and the voltage of the capacitor increases, the current flowing through the power supply 80 and the power supply line of the shut-off device decreases. As a result, an electromotive force V represented by the following equation (1) is generated in the semiconductor circuit breaker 12.

V = V ₀ + (L ₁ (dI ₁ / dt)) + (L ₂ (dI ₂ / dt)) (1)
In the above formula (1), L ₁ is the inductance of the power supply line from the DC power supply 80 to the semiconductor circuit breaker 12, and L ₂ is the inductance of the power supply line from the semiconductor circuit breaker 12 to the load 90. . Further, V ₀ is a power supply voltage of the DC power supply 80, dI ₁ / dt is a time change of a current flowing through the power supply line from the DC power supply 80 to the cutoff device, and dI ₂ / dt is a voltage from the cutoff device to the load 90. It is a time change of the electric current which flows into a feeder.

  In the present embodiment, in a state where no short circuit has occurred, the current flowing from the DC power supply 80 via the feeder line is branched to the capacitor 14, and the capacitor 14 is charged by the branched current. That is, the capacitor 14 stores electric energy. When a short circuit occurs, the capacitor 14 is discharged, and the accumulated electrical energy is output to the positive electrode line 51 as a current from the connection point between the capacitor 14 and the positive electrode line 51.

  In the present embodiment, the connection point between the capacitor 14 and the positive electrode line 51 is upstream of the first connection point with respect to the current flow. As a result, when the current value of the current that flows from the DC power supply 80 via the power supply line and the current that flows due to the discharge of the capacitor 14 reaches a predetermined current value, the current detection unit 13 sends a signal to the control unit 11. Is output.

Therefore, when the semiconductor circuit breaker 12 starts to cut off the current, the current flowing from the DC power supply 80 through the feeder line becomes smaller than that without the capacitor 14. In addition, since a current flows through the capacitor 14 after the start of interruption, the amount of change in current is smaller than that without the capacitor 14. For this reason, in the above formula (1), the electromotive force (L ₁ (dI / dt)) based on the inductance L ₁ is smaller than that without the capacitor 14.

  Further, in the present embodiment, the diode 15 is connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side from the second connection point. As a result, an electric path connecting the positive electrode line 51 and the negative electrode line 52 is formed on the load 90 side of the second connection point, and the current flowing through the power supply line from the interrupting device to the load 90 flows almost unchanged.

Therefore, when the semiconductor circuit breaker 12 starts to cut off the current, an electromotive force (L ₂ (dI ₂ / dt) based on the inductance L ₂ in the above equation (1) is provided between both ends of the semiconductor circuit breaker 12. ) Does not take. That is, when the semiconductor circuit breaker 12 starts to cut off the current, the electromotive force applied between both ends of the semiconductor circuit breaker 12 is the electromotive force (L ₁ (dI) based on the power supply voltage V ₀ by the DC power supply 80 and the inductance L _1. / Dt)) only.

Incidentally, in the shut-off device to the load 90, the electromotive force based on the inductance L _2, a current flows through the diode 15, the current consumed electric energy by the resistance of the feed line, gradually decreases .

  In addition, after a short circuit or overcurrent occurs and the semiconductor breaker 12 cuts off the current, the electrical connection state of the semiconductor breaker 12 is turned on and turned off to prevent overvoltage of the capacitor 14. This is repeated alternately.

  When the electrical connection state of the semiconductor circuit breaker 12 is in the off state, the capacitor 14 is connected between the positive electrode line 51 and the negative electrode line 52 serving as a power supply line, and the current flowing from the DC power supply 80 side is supplied to the capacitor 14. Flows in. For this reason, the voltage of the capacitor 14 increases. In particular, when the capacitance of the capacitor 14 is small, the capacitor 14 is charged by this current, and a large voltage is generated. Originally, it is necessary to use a capacitor with a high breakdown voltage and a semiconductor circuit breaker. However, after the electrical connection state of the semiconductor circuit breaker 12 is once switched off, the capacitor 14 is charged again by switching it on again. The discharged electric charge is discharged to the short circuit side. Thereby, the voltage of the capacitor 14 is lowered.

  The method for switching the electrical connection state of the semiconductor circuit breaker 12 is not limited to the sequence in which the ON state and the OFF state are alternately repeated. For example, when the voltage of the capacitor 14 is detected and the voltage exceeds a predetermined specified value, the semiconductor There is a method of switching the circuit breaker 12 by feeding back the voltage of the capacitor 14 so that the electrical connection state of the circuit breaker 12 is turned on and the electrical connection state of the semiconductor circuit breaker 12 is turned off when the voltage falls below a specified value. . If the power supply voltage is, for example, 400V power supply, the voltage of the capacitor 14 can be turned on at 450V, turned off at 420V, turned on at 420V, and turned off at 390V. Thus, the method for switching the electrical connection state of the semiconductor circuit breaker 12 may be determined in advance.

  FIG. 2 shows an example of a simulation result obtained by measuring a voltage value between both ends of the semiconductor circuit breaker when the current is interrupted in the case of the circuit breaker 10 shown in FIG. 1 and the case of using the semiconductor circuit breaker and the snubber circuit. It is a figure which shows the case where (a) is a figure which shows the case of the interruption | blocking apparatus 10 shown in FIG. 1, (b) is a figure which shows the case where a semiconductor breaker and a snubber circuit are used.

  Referring to FIG. 2, in the case of the breaker 10 shown in FIG. 1, the maximum value of the voltage across the semiconductor breaker 12 when the current is cut off by the semiconductor breaker 12 is determined using a semiconductor breaker and a snubber circuit. It turns out that it is suppressed similarly to the case.

  As described above, the interrupting device 10 of the present embodiment includes the capacitor 14 connected to the positive electrode line 51 and the negative electrode line 52 on the DC power supply 80 side from the first and second connection points, and the load from the second connection point. The diode 15 is connected to the positive electrode line 51 and the negative electrode line 52 on the 90 side and allows a current in the direction from the negative electrode line 52 to the positive electrode line 51 to pass therethrough.

By providing the capacitor 14, the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ is suppressed. Further, since the current flowing from the DC power supply 80 via the feeder line flows into the capacitor 14, the current when the semiconductor breaker 12 starts breaking the current is suppressed, and the voltage value between both ends of the semiconductor breaker 12 is reduced. Can be suppressed.

Further, since the diode 15 is provided, when the semiconductor breaker 12 starts to cut off the current, an electromotive force (L ₂ (dI ₂ / dt)) based on the inductance L ₂ is generated between both ends of the semiconductor breaker 12. It wo n’t take long.

  Therefore, a rapid increase in the voltage value across the semiconductor breaker 12 can be suppressed, and without using a snubber circuit, the semiconductor breaker 12 can be damaged without using a snubber circuit. Current interruption can be realized.

  Further, since it is not necessary to use a snubber circuit, it is possible to realize space saving of the shut-off device.

  In addition, since it is not necessary to use a snubber circuit, a current for charging the snubber circuit capacitor does not flow after the interruption of the current is completed. Therefore, when the current output from the DC power supply 80 is branched to a plurality of power supply systems by the current distribution device and supplied to the load, voltage fluctuations generated by cutting off the current in the power supply system in which a short circuit has occurred, Propagation to a power feeding system in which a short circuit has not occurred can be suppressed.

  FIG. 3 shows simulation results obtained by measuring voltage fluctuations propagated to a power supply system in which no short circuit occurs in the case where the interrupting device 10 shown in FIG. 1 is applied and in the case where a semiconductor circuit breaker and a snubber circuit are applied. It is a figure which shows an example, (a) is a figure which shows the case where the circuit breaker 10 shown in FIG. 1 is applied, (b) is a figure which shows the case where a semiconductor circuit breaker and a snubber circuit are applied. FIG. 3 shows an example where the rated voltage value is 380V.

  Referring to FIG. 3, when the interrupting device 10 shown in FIG. 1 is applied, voltage fluctuations propagated to the power supply system where no short circuit has occurred are suppressed as compared with the case where a semiconductor circuit breaker and a snubber circuit are applied. I understand that.

  In addition, when the current output from the DC power supply 80 is branched into a plurality of power supply systems by the current distribution device and supplied to the load, the overvoltage fluctuation from the power supply system in which a short circuit occurs propagates to other power supply systems. In order to avoid this, the current distribution device needs to include a capacitor. However, in the case of the configuration of the present embodiment, the capacitor 14 can be substituted for the capacitor of the current distribution device. Therefore, it is not necessary to provide a capacitor in the current distribution device, and the current distribution device can be reduced in size.

  Hereinafter, with reference to FIG. 4 and FIG. 5, the flow of control for switching the electrical connection state of the semiconductor circuit breaker 12 by the control unit 11 will be described in detail.

  First, as shown in FIG. 4, the control unit 11 inputs a current value from the current detection unit 13 (step S101). Determine whether a short circuit or overcurrent has occurred in the circuit from the current value. When the control unit 11 determines that no short circuit or overcurrent has occurred (NO in step S102), the control unit 11 returns to step S101 and repeats the process. If it is determined that a short circuit or overcurrent has occurred (YES in step S102), the electrical connection state of the semiconductor circuit breaker 12 is switched from the on state to the off state by a signal from the control unit 11 (step S103).

  When the semiconductor circuit breaker 12 is turned off, a current flows into the capacitor 14 at the previous stage and is charged. When the capacitor 14 is charged, the current flowing into the preceding capacitor 14 gradually decreases. Current continues to flow through the diode 15 at the subsequent stage due to the inductance from the semiconductor circuit breaker 12 to the load 90. At this time, the control unit 11 keeps the semiconductor circuit breaker 12 in the OFF state until a certain time has elapsed (NO in step S104).

  And when fixed time passes (YES of step S104), the control part 11 will switch the electrical connection state of the semiconductor circuit breaker 12 from an OFF state to an ON state (step S105). When the semiconductor circuit breaker 12 is turned on, a current flows from the capacitor 14 in the previous stage through the semiconductor circuit breaker 12 to the short-circuit point (or the capacitor if there is a capacitor in the subsequent stage). Thereby, the voltage of the capacitor | condenser 14 of the front | former stage falls gradually. At this time, the control unit 11 keeps the semiconductor circuit breaker 12 in the ON state until a certain time has elapsed (NO in Step S106).

  And when fixed time passes (YES of step S106), the control part 11 will switch the semiconductor circuit breaker 12 from an ON state to an OFF state (step S107). While the electrical connection state of the semiconductor circuit breaker 12 is switched from the on state to the off state, the current flowing from the DC power supply 80 usually increases. However, since the inductance from the DC power supply 80 to the semiconductor circuit breaker 12 is large, if the electrical connection state of the semiconductor circuit breaker 12 is switched from the on state to the off state in a short time, the amount of increase in current is small. Until the predetermined time elapses (NO in step S108), the semiconductor circuit breaker 12 is left in the OFF state, and the current flowing from the DC power supply 80 to the capacitor 14 is reduced.

  Further, until a certain time has elapsed (YES in step S108) and the current value becomes 0 A (NO in step S109), the process returns to step S105 and the above-described processing is repeated. Then, when the current value becomes 0 A (YES in step S109), a series of control related to interruption is completed.

  In addition to switching the connection state of the semiconductor circuit breaker 12 in a certain time, the connection state of the semiconductor circuit breaker 12 can be switched according to the collector-emitter voltage of the semiconductor circuit breaker 12. As illustrated in FIG. 5, the control unit 11 inputs a current value from the current detection unit 13 (step S201). Determine whether a short circuit or overcurrent has occurred in the circuit from the current value. When the control unit 11 determines that no short circuit or overcurrent has occurred (NO in step S202), the control unit 11 returns to step S201 and repeats the process. If it is determined that a short circuit or overcurrent has occurred (YES in step S202), the electrical connection state of the semiconductor circuit breaker 12 is switched from the on state to the off state by a signal from the control unit 11 (step S203).

  When the semiconductor circuit breaker 12 is turned off, a current flows into the capacitor 14 at the previous stage and is charged. When the capacitor 14 is charged, the current flowing into the preceding capacitor 14 gradually decreases. Current continues to flow through the diode 15 at the subsequent stage due to the inductance from the semiconductor circuit breaker 12 to the load 90. At this time, the control unit 11 continuously monitors the collector-emitter voltage of the semiconductor circuit breaker 12 until the collector-emitter voltage of the semiconductor circuit breaker 12 exceeds the specified value (NO in step S204). The semiconductor circuit breaker 12 is left off.

  When the collector-emitter voltage of the semiconductor circuit breaker 12 exceeds the specified value (YES in step S204), the control unit 11 switches the electrical connection state of the semiconductor circuit breaker 12 from the off state to the on state (step S205). ). When the semiconductor circuit breaker 12 is turned on, a current flows from the capacitor 14 in the previous stage through the semiconductor circuit breaker 12 to the short-circuit point (or the capacitor if there is a capacitor in the subsequent stage). Thereby, the voltage of the capacitor | condenser 14 of the front | former stage falls gradually. At this time, the control unit 11 keeps the semiconductor circuit breaker 12 in the ON state until the collector-emitter voltage of the semiconductor circuit breaker 12 drops below a specified value (NO in step S206).

  Then, when the collector-emitter voltage of the semiconductor circuit breaker 12 drops below a specified value (YES in step S206), the control unit 11 switches the semiconductor circuit breaker 12 from the on state to the off state (step S207). While the electrical connection state of the semiconductor circuit breaker 12 is switched from the on state to the off state, the current flowing from the DC power supply 80 usually increases. However, since the inductance from the DC power supply 80 to the semiconductor circuit breaker 12 is large, if the electrical connection state of the semiconductor circuit breaker 12 is switched from the on state to the off state in a short time, the amount of increase in current is small. Then, the semiconductor circuit breaker 12 is left in the OFF state, and the current flowing from the DC power supply 80 to the capacitor 14 is reduced.

  While the collector-emitter voltage of the semiconductor circuit breaker 12 exceeds the specified value (YES in step S208), the process returns to step S205 and the above-described processing is repeated. Further, until the collector-emitter voltage of the semiconductor circuit breaker 12 becomes equal to or lower than the specified value (NO in step S208) and the current value becomes 0A (NO in step S209), the capacitor 14 is kept in the off state. The current flowing into the is reduced. Then, when the current value becomes 0 A (YES in step S209), a series of control related to the interruption is completed.

  As described above, the control unit 11 controls the operation so that the electrical connection state of the semiconductor circuit breaker 12 is once switched off and then switched on again to discharge the charge charged in the capacitor 14. Thus, even when the capacitor 14 is inserted between the negative electrode line 52 of the positive electrode line 51 on the DC power supply 80 side, the voltage of the capacitor 14 can be decreased without increasing after the interruption. For this reason, the capacitor capacity can be greatly reduced.

(Second Embodiment)
FIG. 6 is a diagram showing a configuration of a second embodiment of a power feeding circuit to which the interrupting device of the present invention is applied.

  In the power supply circuit according to the present embodiment, the interrupting device 20 is different from the interrupting device 10 according to the first embodiment described above in that a capacitor 16 is provided instead of the diode 15. That is, in the present embodiment, the electromotive force suppressing unit is configured by two capacitors, that is, the capacitor 14 that is the first capacitor and the capacitor 16 that is the second capacitor. Since other configurations are the same as those of the first embodiment, detailed description of the other configurations is omitted here.

  The capacitor 16 is connected to the positive electrode line 51 and the negative electrode line 52 on the DC power supply 80 side from the first connection point and on the load 90 side from the second connection point.

  Below, operation | movement of the interruption | blocking apparatus 20 in the electric power feeding circuit comprised as mentioned above is demonstrated.

  First, a case where a short circuit has not occurred in the power feeding circuit shown in FIG. 6 will be described.

  When a short circuit does not occur in the power supply circuit shown in FIG. 6, the capacitor 14 is charged as in the first embodiment described above. Further, the current flowing from the DC power supply 80 through the feeder line also flows into the capacitor 16, and the capacitor 16 is also charged. That is, the capacitors 14 and 16 store electric energy. Since no current flows through the capacitors 14 and 16 after charging, the interrupting device 20 operates in the same manner as when the capacitors 14 and 16 are not provided.

  Next, a case where a short circuit occurs in the power feeding circuit illustrated in FIG. 6 will be described.

  When a short circuit occurs, the charged capacitors 14 and 16 output the accumulated electric energy to the positive electrode line 51 as a current from the connection point between the capacitors 14 and 16 and the positive electrode line 51.

  In the present embodiment, the connection point between the capacitors 14 and 16 and the positive electrode line 51 is upstream of the first connection point with respect to the current flow. As a result, when the current value of the current that flows from the DC power supply 80 via the feeder line and the current that flows due to the discharge of the capacitors 14 and 16 reaches a predetermined current value, the current detection unit 13 controls the control unit 11. Output a signal to

By providing the capacitor 16 in addition to the capacitor 14, the current flowing from the DC power supply 80 through the feeder line when the semiconductor circuit breaker 12 starts interrupting the current is greater than that in the first embodiment. , Even less. In this case, in the above formula (1), the electromotive force (L ₁ (dI / dt)) based on the inductance L ₁ is further smaller than in the case of the first embodiment.

  In the present embodiment, the capacitor 16 is connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side of the second connection point. Thereby, the electric circuit which connects the positive electrode line 51 and the negative electrode line 52 on the load 90 side from the second connection point is formed. Further, when the semiconductor circuit breaker 12 starts to cut off the current, the charging voltage is held in the capacitor 16. This charging voltage has the effect of suppressing the voltage value across the semiconductor breaker 12.

Therefore, the voltage value between both ends of the semiconductor circuit breaker 12 when the semiconductor circuit breaker 12 starts interrupting the current is the electromotive force (L ₁ (dI ₁ / d) based on the power supply voltage V _{0 from the} DC power supply 80 and the inductance L _1. It is a value obtained by further subtracting the charging voltage of the capacitor 16 from the sum of dt)).

  Further, when the semiconductor breaker 12 starts to cut off the current, the current flowing through the semiconductor breaker 12 is the sum of the current flowing from the DC power supply 80 and the current flowing from the capacitor 14, and the current flowing from the capacitor 16 is included. I can't. Therefore, when the semiconductor circuit breaker 12 starts to interrupt current, the current flowing through the semiconductor circuit breaker 12 is suppressed as compared with the case of the first embodiment.

Incidentally, the electromotive force based on the inductance L _2, via the capacitor 16, current flows through the feed line of the load 90 side. The capacitor 16 repeats charging and discharging by this current. That is, as the capacitor 16, it is necessary to use a nonpolar capacitor in which the plus side and the minus side are not fixed. The current flowing through the power supply line on the load 90 side gradually decreases because electric energy is consumed by the resistance of the power supply line.

  As described above, the interrupting device 20 of the present embodiment includes the capacitor 14 connected to the positive electrode line 51 and the negative electrode line 52 on the DC power supply 80 side from the first and second connection points, and the direct current from the first connection point. And a capacitor 16 connected to the positive electrode line 51 and the negative electrode line 52 on the power source 80 side and on the load 90 side of the second connection point.

By providing the capacitor 16 in addition to the capacitor 14, the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ is further suppressed as compared with the case of the first embodiment. Further, since the current flowing from the DC power supply 80 via the feeder line flows into the capacitor 14, the current when the semiconductor circuit breaker 12 starts interrupting the current is suppressed. Therefore, the voltage value between both ends of the semiconductor circuit breaker 12 is further suppressed as compared with the case of the first embodiment.

In addition, since the capacitor 16 is provided, when the semiconductor breaker 12 starts to cut off the current, an electromotive force (L ₂ (dI ₂ / dt)) based on the inductance L ₂ is generated between both ends of the semiconductor breaker 12. It wo n’t take long. Moreover, since the charging voltage is held in the capacitor 16, the voltage value between both ends of the semiconductor circuit breaker 12 is suppressed by the amount corresponding to the charging voltage as compared with the case of the first embodiment.

  Therefore, in this embodiment, the rapid increase of the voltage value between both ends of the semiconductor circuit breaker 12 can be further suppressed as compared with the case of the first embodiment.

(Third embodiment)
In the second embodiment described above, the breaking device 20 includes the nonpolar capacitor 16. In this case, when the current flows by the electromotive force based on the inductance L _2, over discharge occurs in the capacitor 16, there is a possibility that the overvoltage corresponding to the reverse voltage to the semiconductor circuit breaker 12 is applied by the reverse voltage.

  In the present embodiment, a breaker that can avoid the occurrence of overdischarge in the capacitor 16 will be described.

  FIG. 7 is a diagram illustrating a configuration of a third embodiment of a power feeding circuit to which the interrupting device of the present invention is applied.

  The interruption device 30 in the power supply circuit of the present embodiment is different from the interruption device 20 in the second embodiment described above in that a diode 15 is provided. That is, in this embodiment, the capacitor 14 as the first capacitor, the capacitor 16 as the second capacitor, and the diode 15 constitute an electromotive force suppressing unit. Since the other configuration is the same as that of the second embodiment, a detailed description of the other configuration is omitted here.

  The diode 15 is connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side of the second connection point, and allows a current in the direction from the negative electrode line 52 to the positive electrode line 51 to pass therethrough.

  Below, operation | movement of the interruption | blocking apparatus 30 in the electric power feeding circuit comprised as mentioned above is demonstrated.

  First, a case where a short circuit has not occurred in the power feeding circuit shown in FIG. 7 will be described.

  When no short circuit has occurred in the power supply circuit shown in FIG. 7, the capacitors 14 and 16 are charged as in the case of the second embodiment described above. Further, as in the case of the first embodiment described above, since a reverse voltage is always applied to the diode 15, no current flows through the diode 15. Therefore, the cutoff device 30 operates in the same manner as when the capacitors 14 and 16 and the diode 15 are not provided.

  Next, a case where a short circuit occurs in the power feeding circuit illustrated in FIG. 7 will be described.

  When a short circuit occurs and the semiconductor circuit breaker 12 starts to interrupt current, the electromotive force V represented by the above formula (1) is applied to the semiconductor circuit breaker 12 as in the first and second embodiments. appear.

  In the present embodiment, capacitors 14 and 16 are provided as in the second embodiment. The connection point between the capacitors 14 and 16 and the positive electrode line 51 is upstream of the first connection point with respect to the current flow.

Therefore, when the semiconductor circuit breaker 12 starts interrupting the current, the current flowing from the DC power supply 80 via the feeder line is further increased than in the first embodiment, as in the second embodiment. Less. In this case, similarly to the case of the second embodiment, in the above formula (1), the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ is larger than that in the case of the first embodiment. It becomes even smaller.

  In the present embodiment, the capacitor 16 is connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side with respect to the second connection point, as in the second embodiment. Thereby, the electric circuit which connects the positive electrode line and negative electrode line 52 of the load 90 side rather than the 2nd connection point is formed. Further, when the semiconductor circuit breaker 12 starts to cut off the current, the charging voltage is held in the capacitor 16.

Therefore, when the semiconductor circuit breaker 12 starts to cut off the current, the electromotive force applied between the both ends of the semiconductor circuit breaker 12 is similar to the second embodiment in that the power supply voltage V ₀ and the inductance L ₁ by the DC power supply 80 are as follows. It is a value obtained by further subtracting the charging voltage of the capacitor 16 from the sum of the electromotive force based on (L ₁ (dI ₁ / dt)).

  In addition, when the semiconductor circuit breaker 12 starts to cut off the current, the current flowing through the semiconductor circuit breaker 12 does not include the current flowing from the capacitor 16, so that the first embodiment is similar to the second embodiment. It is suppressed more than the case.

  Thus, the interruption device 30 of the present embodiment is connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side of the second connection point as compared with the interruption device 20 in the second embodiment described above, and the negative electrode line A diode 15 is further provided for passing a current in the direction from 52 to the positive electrode line 51.

By providing the capacitor 16 in addition to the capacitor 14, the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ is higher than that in the case of the first embodiment, as in the second embodiment. Is further suppressed. Further, since the current flowing from the DC power supply 80 via the feeder line flows into the capacitor 14, the current when the semiconductor circuit breaker 12 starts interrupting the current is suppressed. Therefore, as in the case of the second embodiment, the voltage value across the semiconductor breaker 12 is further suppressed than in the case of the first embodiment.

In addition, since the capacitor 16 is provided, when the semiconductor breaker 12 starts to cut off the current, an electromotive force (L ₂ (dI ₂ / dt)) based on the inductance L ₂ is generated between both ends of the semiconductor breaker 12. It does n’t take a long time. Further, since the charging voltage is held in the capacitor 16 as in the second embodiment, the voltage value across the semiconductor breaker 12 is equal to the charging voltage in the case of the first embodiment. Smaller than.

Furthermore, the diode 15 due to the provision of the, when a current flows due to an electromotive force based on the inductance L _2, can avoid the over-discharge the capacitor 16 occurs.

  Therefore, in this embodiment, while avoiding the problems that may occur in the second embodiment, the voltage value across the semiconductor breaker 12 is increased more rapidly than in the first embodiment. Can be further suppressed.

  Note that, by using the configuration as in the present embodiment, it is possible to use a nonpolar capacitor as the capacitor 16.

(Fourth embodiment)
In the second and third embodiments described above, when the capacitor 16 is charged, if the current suddenly flows from the positive electrode line 51 to the capacitor 16, the capacitor 16 may be broken and short-circuited. is there.

  In the present embodiment, a breaker that can avoid short-circuiting the capacitor 16 will be described.

  FIG. 8 is a diagram showing a configuration of a fourth embodiment of a power feeding circuit to which the interrupting device of the present invention is applied.

  In the power supply circuit according to the present embodiment, the interrupting device 40 is different from the interrupting device 10 according to the second embodiment described above in that it includes a parallel circuit 41 including a diode 15 and a resistor 17. That is, in this embodiment, the electromotive force suppression unit is configured by the capacitor 14 that is the first capacitor, the capacitor 16 that is the second capacitor, and the parallel circuit 41. Since the other configuration is the same as that of the second embodiment, a detailed description of the other configuration is omitted here.

  The parallel circuit 41 is connected to the positive electrode line 51, and the capacitor 16 is connected to the negative electrode line 52.

  The parallel circuit 41 and the capacitor 16 are connected in series, and are connected to the positive electrode line 51 and the negative electrode line 52 on the DC power supply 80 side from the first connection point and on the load 90 side from the second connection point. Yes.

  The diode 15 passes a current in the direction from the capacitor 16 to the positive electrode line 51.

  Below, operation | movement of the interruption | blocking apparatus 40 in the electric power feeding circuit comprised as mentioned above is demonstrated.

  First, a case where a short circuit has not occurred in the power feeding circuit shown in FIG. 8 will be described.

  When the short circuit does not occur in the power feeding circuit illustrated in FIG. 8, the capacitor 14 is charged as in the first to third embodiments described above. Further, the current flowing from the DC power supply 80 through the feeder line also flows into the capacitor 16 through the resistor 17, and the capacitor 16 is also charged. Furthermore, since a reverse voltage is always applied to the diode 15, no current flows through the diode 15. Therefore, the interruption device 40 operates in the same manner as when the capacitors 14 and 16 and the parallel circuit 41 are not provided.

  Next, a case where a short circuit occurs in the power feeding circuit illustrated in FIG. 8 will be described.

  When a short circuit occurs and the semiconductor circuit breaker 12 starts to interrupt current, the electromotive force V represented by the above formula (1) is applied to the semiconductor circuit breaker 12 as in the first to third embodiments. appear.

  In the present embodiment, capacitors 14 and 16 are provided as in the second and third embodiments. The connection point between the capacitor 14 and the parallel circuit 41 and the positive electrode line 51 is upstream of the first connection point with respect to the current flow.

Therefore, when the semiconductor circuit breaker 12 starts to cut off the current, the current flowing from the DC power supply 80 via the feeder line is the same as in the second and third embodiments in the case of the first embodiment. Even less than. In this case, as in the case of the second and third embodiments, in the above formula (1), the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ is the same as that of the first embodiment. Even smaller than the case.

  In the present embodiment, the parallel circuit 41 and the capacitor 16 are connected to the positive electrode line 51 and the negative electrode line 52 on the load 90 side from the second connection point. Thereby, the electric circuit which connects the positive electrode line and negative electrode line 52 of the load 90 side rather than the 2nd connection point is formed. Further, when the semiconductor circuit breaker 12 starts to cut off the current, the charging voltage is held in the capacitor 16.

Therefore, when the semiconductor circuit breaker 12 starts to cut off the current, the electromotive force applied between both ends of the semiconductor circuit breaker 12 is the same as the power supply voltage V ₀ by the DC power supply 80 as in the second and third embodiments. This is a value obtained by further subtracting the charging voltage of the capacitor 16 from the sum of the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ .

  In addition, when the semiconductor circuit breaker 12 starts to cut off the current, the current flowing through the semiconductor circuit breaker 12 does not include the current flowing from the capacitor 16, so that the first and second embodiments are similar to the first and third embodiments. It is suppressed more than in the case of the embodiment.

When a short circuit occurs, a current flows through the power supply line on the load 90 side via the capacitor 16 and the diode 15 of the parallel circuit 41. After the 0V voltage of the capacitor 16, the electromotive force based on the inductance L _2, the discharge current discharge followed via the capacitor 16 diode 15 becomes zero discharge ends. After discharging, the battery is slowly charged via the resistor 17. That is, the capacitor 16 needs to be a nonpolar capacitor.

  As described above, the interrupting device 40 of the present embodiment is connected to the capacitor 14 connected to the positive electrode line 51 and the negative electrode line 52 on the DC power supply 80 side from the first and second connection points, and to the positive electrode line 51, and the diode 15 and a resistor 17, and a capacitor 16 connected to a negative electrode line 52. The parallel circuit 41 and the capacitor 16 are connected in series, and the parallel circuit 41 and the capacitor 16 are positive on the DC power supply 80 side from the first connection point and on the load 90 side from the second connection point. The line 51 and the negative electrode line 52 are connected. The diode 15 allows a current in the direction from the capacitor 16 to the positive electrode line 51 to pass therethrough.

By providing the capacitor 16 in addition to the capacitor 14, the electromotive force (L ₁ (dI ₁ / dt)) based on the inductance L ₁ is the same as that of the _first embodiment, as in the second and third embodiments. This is even smaller than in the case of. Further, since the current flowing from the DC power supply 80 via the feeder line flows into the capacitor 14, the current when the semiconductor circuit breaker 12 starts interrupting the current is suppressed. Therefore, as in the second and third embodiments, the voltage value across the semiconductor circuit breaker 12 is further suppressed than in the first embodiment.

In addition, since the parallel circuit 41 and the capacitor 16 are provided, an electromotive force (L ₂ (dI / dt)) based on the inductance L ₂ is generated when the semiconductor circuit breaker 12 starts to block current. No longer takes between the two ends. Similarly to the second and third embodiments, since the charging voltage is held in the capacitor 16, the voltage value between both ends of the semiconductor circuit breaker 12 is the same as that in the first embodiment. It becomes smaller than the case of form.

  Furthermore, since a current flows into the capacitor 16 from the positive electrode line 51 through the resistor 17, the current does not suddenly flow into the capacitor 16, and the capacitor 16 can be prevented from being short-circuited.

  Therefore, in the present embodiment, while avoiding the problems that may occur in the second and third embodiments, a rapid increase in the voltage value across the semiconductor circuit breaker 12 is performed in the first embodiment. This can be suppressed more than in the case of.

Incidentally, when the current flows by the electromotive force based on the inductance L _2, in order to avoid over-discharge the capacitor 16 occurs, may be further provided in the same manner as in the third embodiment diode .

  FIG. 9 is a diagram illustrating an example of a configuration in the case where the blocking device 40 illustrated in FIG. 8 is further provided with a diode.

  By adopting a configuration such as the cutoff device 50 shown in FIG. 9, it is possible to avoid the occurrence of overdischarge in the capacitor 16 as in the case of the third embodiment.

  Further, in the first to fourth embodiments described above, an increase in current between the time when the current detection unit 13 detects a predetermined current value and the time when the semiconductor circuit breaker 12 starts to interrupt current is suppressed. Therefore, an inductor may be provided on the feeder line.

(Modification)
In the first to fourth embodiments described above, the case where the semiconductor circuit breaker 12 and the current detection unit 13 are connected to the positive electrode line 51 has been described as an example. However, the semiconductor circuit breaker 12 and the current detection unit are described. 13 may be connected on the negative electrode line 52. One of the semiconductor circuit breaker 12 and the current detection unit 13 may be connected to the positive electrode line 51 and the other may be connected to the negative electrode line 52. For example, current detection units 13b and 13c similar to the current detection unit 13 can be connected to a location as shown in FIG. Further, when the voltage of the capacitor 14 is detected and the electrical connection state of the semiconductor circuit breaker 12 is switched, a voltage detection unit 63 that detects the voltage of the capacitor 14 may be connected as shown in FIG. Furthermore, when detecting a short circuit or overcurrent, the short circuit or overcurrent can also be detected by a method other than using the current detection unit 13.

(Summary)
Without using a snubber circuit, the current can be interrupted without damaging the semiconductor circuit breaker 12. In addition, when a short circuit or overcurrent occurs and the electrical connection state of the semiconductor circuit breaker 12 is turned off, the control unit 11 turns the electrical connection state of the semiconductor circuit breaker 12 on. Control to repeat the process. By switching the electrical connection state of the semiconductor circuit breaker 12 to the on state, the charge of the capacitor 14 can be discharged, and the voltage can be lowered before the capacitor 14 becomes overvoltage.

  INDUSTRIAL APPLICABILITY The present invention can be used as a cutoff device for protecting various loads operating with a DC power supply from short circuits and overcurrents.

10, 20, 30, 40, 50, 61, 62 Interrupting device 11 Control unit 12 Semiconductor circuit breaker 13 Current detection unit 14, 16 Capacitor 15 Diode 17 Resistance 41 Parallel circuit 51 Positive line 52 Negative electrode 63 Voltage detection unit 80 DC power supply 90 load

Claims (8)

A shut-off device provided between a load fed from a DC power supply via a power supply line and the DC power supply,
A current detector that is connected to a first connection point on the power supply line and detects a current value of a current flowing through the first connection point;
A semiconductor circuit breaker that is connected to a second connection point on the feeder line and starts to cut off a current flowing through the second connection point when a current value detected by the current detection unit reaches a predetermined current value. When,
When the current flowing through the power supply line is branched and electrical energy is accumulated by the branched current, and the current flowing through the power supply line continues to increase, the stored electrical energy is upstream of the first connection point. When the semiconductor breaker starts to cut off the current as current, and the semiconductor circuit breaker starts to cut off the current, the electric path connecting the positive electrode line and the negative electrode line constituting the power supply line on the load side from the second connection point And an electromotive force suppressing unit that causes a current corresponding to the electromotive force generated by the start of the interruption to flow through the electric circuit,
The electromotive force suppression unit is
When the semiconductor circuit breaker is interrupting a current, the circuit breaker temporarily energizes the semiconductor circuit breaker, and outputs the stored electric energy as a current to the feeder line. The shut-off device according to claim 1,
The electromotive force suppression unit is
A first capacitor connected to the positive electrode line and the negative electrode line on the DC power supply side from the first and second connection points;
And a diode that is connected to the positive line and the negative line on the load side of the second connection point and allows a current in a direction from the negative line to the positive line to pass therethrough. The shut-off device according to claim 1,
The electromotive force suppression unit is
A first capacitor connected to the positive electrode line and the negative electrode line on the DC power supply side from the first and second connection points;
A non-polar second capacitor connected to the positive electrode line and the negative electrode line on the DC power source side with respect to the first connection point and on the load side with respect to the second connection point. apparatus. The shut-off device according to claim 3,
The electromotive force suppression unit is
The first and second capacitors;
And a diode that is connected to the positive line and the negative line on the load side of the second connection point and allows a current in a direction from the negative line to the positive line to pass therethrough. The shut-off device according to claim 1,
The electromotive force suppression unit is
A first capacitor connected to the positive electrode line and the negative electrode line on the DC power supply side from the first and second connection points;
A parallel circuit connected to the positive line and comprising a first diode and a resistor;
A non-polar second capacitor connected to the negative electrode wire,
The parallel circuit and the second capacitor are connected in series;
The parallel circuit and the second capacitor are connected to the positive electrode line and the negative electrode line on the DC power supply side with respect to the first connection point and on the load side with respect to the second connection point,
The first diode is a cutoff device that allows a current in a direction from the second capacitor to the positive line to pass therethrough. The shut-off device according to claim 5,
The electromotive force suppression unit is
The first and second capacitors;
The parallel circuit;
And a second diode that is connected to the positive electrode line and the negative electrode line on the load side of the second connection point and allows a current in a direction from the negative electrode line to the positive electrode line to pass therethrough. In the interruption | blocking apparatus of any one of Claims 2-6,
A voltage detector for detecting a voltage between a collector and an emitter of the semiconductor breaker;
The electromotive force suppression unit is
When the semiconductor circuit breaker is blocking current, if the voltage between the collector and emitter of the semiconductor circuit breaker detected by the voltage detector exceeds a predetermined reference voltage, the semiconductor circuit breaker is temporarily A shut-off device that is energized and outputs the stored electrical energy as a current to the feeder line. In the interruption | blocking apparatus of any one of Claims 2-6,
A voltage detection unit for detecting a voltage between both terminals of the first capacitor;
The electromotive force suppression unit is
When the semiconductor circuit breaker is interrupting current, if the voltage between both terminals of the first capacitor detected by the voltage detection unit exceeds a predetermined reference voltage, the semiconductor circuit breaker is temporarily A shut-off device that is energized and outputs the stored electrical energy as a current to the feeder line.

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