JP2016103427A - DC current cutoff device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC current cutoff device which has less transmission loss and can be miniaturized.SOLUTION: A DC current cutoff device 3 comprises a semiconductor element part in which a self-excited semiconductor element 11 and a thyristor are connected in series, an arrester 9 which is connected to the thyristor in parallel, a semiconductor breaker 5 in which a semiconductor part and a capacitor 10 are connected in parallel, a current suppression reactor 6 which is connected to the semiconductor breaker 5 in series, and a mechanical contact type disconnector 7 which is connected to the semiconductor breaker 5 in series.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a direct current interruption device.

  In recent years, the spread of renewable energy such as wind power generation, solar power generation, and solar thermal power generation has been promoted. Offshore wind power generation, solar power generation in the desert, and solar thermal power generation have begun to be studied in order to supply large amounts of power with renewable energy. In offshore wind power generation, the generated power is transmitted to the city where it is consumed by a submarine cable, and in the desert area, solar power is generated from desert areas in the back of Africa and China, to large cities in Europe and coastal areas. It is necessary to transmit a large amount of power over a long distance with high efficiency. Since direct current power transmission is more efficient than conventional three-phase alternating current power transmission and can be installed with reduced cable costs, the application of a direct current power transmission system to high-power long-distance transmission has been studied.

  Compared to conventional AC transmission systems, DC transmission systems can be installed at low cost when applied to long-distance, high-power transmission, and have low transmission loss. It is difficult to isolate the location where the system accident occurred. In an AC power transmission system, a mechanical contact breaker can interrupt current at a point where AC current crosses zero every half cycle at an AC frequency of 50 Hz or 60 Hz, whereas in DC current, the current crosses zero. Therefore, in a mechanical contact type circuit breaker, an arc is generated at the contact and the current cannot be easily interrupted.

  Since the DC power transmission system has a low line impedance, the voltage propagation speed is fast, and a circuit breaker that can be cut off in a few ms is required to prevent the voltage from propagating several hundred kilometers away. When constructing a power transmission network, there is a requirement that the point of occurrence of the accident must be separated from the power transmission network at high speed and the operation must be continued only with a healthy power transmission network. Without a device, it is impossible to build a DC power grid.

  A mechanical contact type circuit breaker is used as a circuit breaker for a direct current railway. This mechanical contact type circuit breaker accumulates electric charge in a capacitor or the like in advance, discharges the capacitor electric charge when an accident occurs, generates a zero point by LC resonance, and extinguishes the arc. The DC feeder railway has several kV even if the feeding voltage is high, and even if the opening distance of the mechanical contact is short, the insulation withstand voltage can be secured, and the interruption is completed in a few ms. On the other hand, in a DC power transmission system, the transmission voltage reaches several hundreds kV, and it is necessary to increase the opening distance in order to secure the insulation withstand voltage. It is difficult to apply a circuit breaker for a railway to a DC power grid.

  In contrast to a mechanical contact type circuit breaker, a circuit breaker using a semiconductor element having a self-extinguishing capability such as an IGBT can be cut off only by turning off a drive electric signal. The current interruption time of the semiconductor is several μs, which sufficiently satisfies the interruption time required for the DC power transmission network. However, the semiconductor circuit breaker has a large voltage drop and a large loss during power transmission, so far it has not been actively used for direct current power transmission.

  As a method for solving this problem, a hybrid circuit breaker has been proposed in which another semiconductor circuit breaker is connected in parallel to a circuit in which a mechanical contact disconnector and an auxiliary semiconductor disconnector are connected in series. In the hybrid circuit breaker, during power transmission, the series circuit of the mechanical contact disconnector and the auxiliary semiconductor circuit breaker is turned on, and the semiconductor circuit breaker is turned off. The transmission current flows through the series circuit side of the mechanical contact disconnector and auxiliary semiconductor circuit breaker.

  When a system fault occurs, turn off the auxiliary semiconductor breaker and simultaneously turn on the parallel semiconductor breaker. As a result, all fault currents begin to flow through the parallel circuit breaker. Accident current can be cut off by disconnecting the mechanical contact type disconnector when the current of the mechanical contact type disconnector becomes zero and turning off the parallel-side semiconductor circuit breaker while ensuring the insulation withstand voltage. become.

Japanese National Patent Publication No. 10-506260 WO2011 / 34140 Publication

  In order to apply an IGBT having a maximum breaking current of several kA to a semiconductor breaker or a hybrid breaker, it is necessary to install a reactor to suppress the accident current to several kA. If the breaking current is small, the inductance of the reactor must be increased, and the number of turns increases, so the resistance of the reactor increases. Since current flows through the reactor during power transmission, an increase in resistance leads to an increase in power transmission loss, which increases running costs. Further, a semiconductor element having a self-extinguishing capability needs to supply driving power from the outside. In order to supply power to a circuit breaker having a high ground potential while providing insulation of several hundred kV, a large insulation transformer is required, which increases the size and cost of the circuit breaker.

  An object of the present invention is to provide a direct current interrupting device that has a small power transmission loss and can be miniaturized.

The direct current interrupt device of this embodiment has the following configuration.
(1) A semiconductor element portion in which a forward self-excited semiconductor element and a forward thyristor are connected in series. (2) An arrester connected in parallel to the forward thyristor.
(3) A semiconductor circuit breaker in which the semiconductor element portion and the capacitor are connected in parallel.
(4) A current suppressing reactor connected in series with the semiconductor breaker.
(5) A mechanical contact disconnector or circuit breaker connected in series with the semiconductor circuit breaker.

The circuit diagram which shows the structure of 1st Embodiment. The time chart which shows operation | movement of 1st Embodiment. The circuit diagram which shows the structure of 2nd Embodiment. A circuit diagram showing composition of a 3rd embodiment. The time chart which shows operation | movement of 3rd Embodiment. The circuit diagram which shows the structure of 4th Embodiment. The time chart which shows operation | movement of 4th Embodiment. The circuit diagram which shows the structure of 5th Embodiment.

[1. First Embodiment]
[1-1. Constitution]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a DC current interrupting device 3 according to a first embodiment that interrupts and electrically insulates a DC voltage source 1 and an accident point 4 occurring in a power transmission line 2 such as a cable or an overhead wire.

  The DC current interrupting device 3 includes a semiconductor circuit breaker 5, a current suppressing reactor 6 connected in series to the DC voltage source 1 side, and a mechanical contact disconnector 7 connected to the power transmission line 2 side of the semiconductor circuit breaker 5. Is provided. The semiconductor circuit breaker 5 includes a semiconductor element unit 8, an arrester 9 connected in parallel to the semiconductor element unit 8, and a capacitor 10 connected in parallel to the semiconductor element unit 8. The limiting voltage of the arrester 9 is normally set to 1.5 times or more of the DC transmission voltage.

  The mechanical contact disconnector 7 cuts off the line by opening the movable contact with respect to the fixed contact. The mechanical contact breaker 7 may be a mechanical contact breaker that cuts off current at a zero point generated by LC resonance generated between the capacitor 10 and the transmission line. However, when the semiconductor element unit 8 is completely cut off, the fault current is attenuated by the resistance between the capacitor 10 and the transmission line 2, so that a disconnector having no current cut-off capability can be used.

  The semiconductor element unit 8 includes a self-excited semiconductor element 11 (hereinafter referred to as IGBT) such as IGBT or IEGT, and a forward thyristor 12 connected in series with the IGBT 11. The IGBT is connected to the DC voltage source 1 in a direction (forward direction) in which a current from the DC voltage source 1 is passed. This forward IGBT 11 incorporates a diode that allows a current to pass in a direction opposite to the direction in which the current flows. The forward thyristor 12 is connected to the forward IGBT 11 in a direction (forward direction) in which a current can flow from the DC voltage source 1 to the power transmission line 2. The forward IGBT 11 and the forward thyristor 12 have one or more elements connected in series according to the transmission voltage. The forward thyristor 12 is connected in parallel with a diode 13 that allows current to flow in the opposite direction to the forward thyristor 12.

  The direct current interrupter 3 is provided with a control device (not shown). This control device detects that an electric current flowing through the power transmission line 2 has increased by a device such as a current sensor, determines that an accident has occurred based on the detection result, and detects the semiconductor breaker 5 and the mechanical contact disconnector. 7 to open command.

  The capacitor 10 has a withstand voltage equivalent to a DC transmission voltage. The capacitance of the capacitor 10 is determined as follows. The voltage of the capacitor 10 rises during a period of several μs when the current of the forward thyristor 12 is turned off, and the voltage rise value does not exceed the withstand voltage of the self-excited semiconductor element 11. For example, when the forward IGBT 11 is turned off for 10 μs, the withstand voltage of the forward IGBT 11 is 2 kV, and the current at the time of commutation to the capacitor 10 is 5 kA, the relationship of charge Q = capacitance C × voltage V is 5 kA × 10 μs. = Capacitance C = 25 μF is calculated from the capacitance C × 2 kV. Since the forward IGBT 11 is off for a very short time, the capacity of the capacitor 10 can be suppressed, and the addition of the capacitor 10 has little influence on the increase in size and cost of the device.

[1-2. Action]
In a normal state before the accident occurs, the forward IGBT 11 and the forward thyristor 12 are turned on, and the DC voltage source 1 → current suppression reactor 6 → forward IGBT 11 → forward thyristor 12 → mechanical contact disconnector 7 → feed A direct current flows to the electric wire 2, and direct-current power is sent. Alternatively, a current is passed in the direction of the power transmission line 2 → the mechanical contact type disconnector 7 → the diode 13 connected in parallel with the forward thyristor 12 → the diode incorporated in the forward IGBT 11 → the current suppressing reactor 6 → the DC voltage source 1. It is also possible to send power in the reverse direction.

FIG. 2 is a diagram showing the current flowing through each part of the DC current interrupting device 3 in time series after an accident occurs. The operation of the circuit breaker at the time of the accident will be described with reference to FIG.
When an accident occurs in the transmission line 2 due to a lightning strike or the like, the voltage at the accident point 4 decreases, and the DC voltage source 1 → current suppression reactor 6 → forward IGBT 11 → forward thyristor 12 → mechanical contact disconnector 7 → transmission line 2 A fault current is supplied to the current and the current increases.

  The DC current interrupting device 3 detects that an accident has occurred due to an increase in current by a control device (not shown), and starts control to open the circuit breaker. First, the signals driving the forward IGBT 11 and the forward thyristor 12 are turned off. When the forward IGBT 11 is turned off, the fault current is commutated from the forward IGBT 11 to the forward thyristor 12 to the capacitor 10 connected in parallel. The current flowing from the forward IGBT 11 to the forward thyristor 12 becomes equal to or less than the holding current of the forward thyristor 12, and the forward thyristor 12 current is turned off. As a result of the commutation of the fault current, if the voltage of the capacitor 10 increases, the withstand voltage of the forward IGBT 11 may be exceeded. Therefore, the forward IGBT 11 is turned on again after several tens of μs.

  The accident current continues to flow from the current suppressing reactor 6 → the capacitor 10 → the mechanical contact type disconnector 7 → the transmission line 2, and the voltage of the capacitor 10 increases. When the voltage of the capacitor 10 reaches the limit voltage of the arrester 9, which is normally set to 1.5 times or more of the DC transmission voltage, the fault current is commutated to the arrester 9.

  The accident current continues to flow from the current suppression reactor 6 to the arrester 9 → the mechanical contact disconnector 7 → the transmission line 2, and the energy stored in the inductance of the current suppression reactor 6 and the transmission line 2 is consumed by the arrester 9. The current flows through the arrester 9 until the current becomes zero, and thereafter, since the inductance and the capacitor 10 are included in the power transmission path, LC resonance occurs and the resistance component attenuates. The mechanical contact disconnector 7 isolates the semiconductor circuit breaker 5 from the accident point 4.

[1-3. effect]
According to this embodiment, since the semiconductor element unit 8 is configured by the combination of the forward IGBT 11 and the forward thyristor 12, the number of forward IGBTs 11 having a low current withstand capability can be greatly reduced. The thyristor used in place of the forward IGBT 11 has a feature that the withstand current is large, and can increase the breaking current of the circuit breaker. In order to match the thyristor cutoff current, a plurality of forward IGBTs 11 connected in series to the forward thyristor 12 must be arranged in parallel. However, since the required withstand voltage of the forward IGBT 11 is small, the number of use is small. In particular, it is possible to prevent the forward IGBT 11 from being damaged by turning on the forward IGBT 11 in a short time after the fault current commutates to the capacitor 10.

  Thyristors are semiconductor elements that are often used for separately-excited DC power transmission, and since they are used in environments with high ground voltage, they can be ignited with a small amount of optical signal power and can be driven by simply connecting an optical fiber cable. Optical trigger thyristors have been put into practical use. By using such a thyristor, the drive circuit can be simplified, which has a great effect on the size reduction and cost reduction of the circuit breaker.

  Although it is necessary to add the capacitor 10 having a withstand voltage equivalent to the voltage used for direct current power transmission, since the forward IGBT 11 is off for a very short time, the capacity of the capacitor 10 can be suppressed. The impact on the increase in size and cost of the equipment is small.

[Second Embodiment]
[2-1. Constitution]
A second embodiment will be described with reference to FIG. FIG. 3 shows a configuration in which both ends of the circuit breaker are connected to the power transmission line 2 and can be interrupted even if an accident occurs on either side. In the second embodiment, compared to the first embodiment, a reverse IGBT 14 is added to the forward IGBT 11, and the parallel diode 13 of the forward thyristor 12 has a reverse characteristic that is reverse to that of the forward thyristor 12. The direction thyristor 15 is replaced.

[2-2. Action]
In a normal state before the accident occurs, the forward IGBT 11 and the forward thyristor 12 are turned on, the DC voltage source 1 → the current suppressing reactor 6 → the diode incorporated in the reverse IGBT 14 → the forward IGBT 11 → the forward thyristor 12. → Mechanical contact type disconnect switch 7 → Direct current flows to the transmission line 2 and direct current power is sent. In addition, the current flows in the direction of the power transmission line 2 → the mechanical contact disconnector 7 → the reverse thyristor 15 → the diode incorporated in the forward IGBT 11 → the reverse IGBT 14 → the current suppressing reactor 6 → the DC voltage source 1 and in the reverse direction. You can also send power.

  In the second embodiment, when the fault point 4 occurs on the transmission line 2 side of the DC current interrupting device 3 and the fault current flows from the DC voltage source 1 to the transmission line 2 as in the first embodiment, the DC voltage The fault current is supplied to the source 1 → the current suppressing reactor 6 → the diode incorporated in the reverse IGBT 14 → the forward IGBT 11 → the forward thyristor 12 → the mechanical contact type disconnector 7 → the transmission line 2, and the current increases. The DC current interrupting device 3 detects that an accident has occurred due to an increase in current by a control device (not shown), and starts control to open the circuit breaker. First, the signals driving the forward IGBT 11 and the forward thyristor 12 are turned off. The following operations are the same as those in the first embodiment.

  In the second embodiment, the fault point 4 occurs on the DC voltage source 1 side of the DC current interrupting device 3, and the fault current is incorporated in the power transmission line 2 → the mechanical contact disconnector 7 → the reverse thyristor 15 → the forward IGBT 11. When the current flows from the diode → reverse IGBT 14 → current suppression reactor 6 → DC voltage source 1, the DC current interrupting device 3 that detects the increase in the accident current first drives the reverse IGBT 14 and the reverse thyristor 15. Turn off the signal. In the following, the same processing as when an accident current flows in the forward direction is performed, and finally the accident point 4 is isolated by the mechanical contact disconnector 7.

[2-3. effect]
In the second embodiment, in addition to the effects of the first embodiment, there is an advantage that a current zero point is generated even for an accident current in the forward direction and in the reverse direction, and isolation by the mechanical contact disconnector 7 is possible.

[Third Embodiment]
[3-1. Constitution]
A third embodiment will be described with reference to FIG. In the third embodiment, in addition to the second embodiment, the mechanical contact disconnector 16 and the semiconductor circuit breaker 5 are combined to reduce the loss during power transmission. That is, a mechanical contact disconnector 16 is connected in parallel with the semiconductor circuit breaker 5, and a forward IGBT 17 for the disconnector and a reverse IGBT 18 for the disconnector are connected in series to the mechanical contact disconnector 16.

[3-2. Action]
The operation of the third embodiment will be described with reference to FIG.
At the time of power transmission, current is passed through the path of current suppression reactor 6 → mechanical contact disconnector 16 → reverse IGBT 18 for disconnector → forward IGBT 17 for disconnector → mechanical contact disconnector 7 → transmission line 2 and DC power Power transmission. Since the current passes through the diodes of the forward IGBT 17 for the disconnector and the reverse IGBT 18 for the disconnector having a small withstand voltage, the voltage drop is small and power can be transmitted with high efficiency.

  When an accident point 4 occurs on the transmission line 2 side of the DC current interrupting device 3, the DC current interrupting device 3 detects that an accident has occurred due to an increase in current, and first opens the mechanical contact disconnector 16 The forward IGBT 17 for the disconnector connected in series to the mechanical contact disconnector 16 is turned off. Then, the fault current is commutated from the path passing through the mechanical contact disconnector 16 to the semiconductor circuit breaker 5 side, the current suppressing reactor 6 → the diode incorporated in the reverse IGBT 14 → the forward IGBT 11 → the forward thyristor 12 → the machine. It flows from the contact type disconnector 7 to the transmission line 2. As a result, since the current of the mechanical contact disconnector 16 becomes zero, the current can be interrupted without generating an arc. Since the fault current flows through the semiconductor circuit breaker 5 in the same manner as in the first embodiment after the disconnector is interrupted, the DC current interrupting device 3 is a signal that drives the forward IGBT 11 and the forward thyristor 12. Turn off. The following operations are the same as those in the first embodiment.

  In the third embodiment, similarly to the second embodiment, the semiconductor circuit breaker 5 includes the reverse IGBT 14 and the reverse thyristor 15 so that the reverse fault current can be cut off. The mechanical contact disconnector 16 is provided with a reverse IGBT 18 for the disconnector. Therefore, at the time of normal current supply and when an accident occurs, current can be passed or cut off in both the forward and reverse directions.

[3-3. effect]
In the third embodiment, in addition to the effects of the first and second embodiments, the current that normally flows passes through the diodes of the forward IGBT 17 for the disconnector and the reverse IGBT 18 for the disconnector that have a low withstand voltage. The effect is that the descent is small and power can be transmitted with high efficiency.

[Fourth Embodiment]
[4-1. Constitution]
A fourth embodiment will be described with reference to FIG. FIG. 6 shows a configuration in which a loss at the time of power transmission is reduced by providing a mechanical contact breaker 19 for a disconnector instead of the forward IGBT 17 for the disconnector and the reverse IGBT 18 for the disconnector in the third embodiment. . In the fourth embodiment, a mechanical contact breaker 19 for a disconnecting switch is connected in series to the mechanical contact disconnecting switch 16. A commutation adjusting reactor 20 is connected between the semiconductor circuit breaker 5 and the mechanical contact disconnector 7. The end of the mechanical contact breaker 19 for the disconnecting switch on the power transmission line 2 side is connected between the mechanical contact disconnecting switch 7 and the commutation adjusting reactor 20.

  Two half-bridge circuits connected in series so as to connect an intermediate point between the mechanical contact disconnector 16 and the mechanical contact breaker 19 for the disconnector and an intermediate point between the semiconductor breaker 5 and the commutation adjusting reactor 20 (Hereinafter referred to as H-bridge circuit 21). The H bridge circuit 21 corresponds to the commutation circuit described in the claims, and functions as an inverter. As shown in the enlarged portion of FIG. 6, the H bridge circuit 21 includes four IGBTs 22a to 22d and a capacitor 23 connected in parallel thereto.

[4-2. Action]
The operation of this embodiment will be described with reference to FIG.
At the time of power transmission, current is passed through the path of the current suppression reactor 6 → the mechanical contact type disconnector 16 → the mechanical contact type circuit breaker 19 for the disconnector → the mechanical contact type disconnector 7 → the power transmission line 2 to transmit DC power. Since the current does not pass through the semiconductor, it can be transmitted with high efficiency without causing any loss.

  When an accident occurs, it is detected that the accident has occurred due to an increase in current, and a command to open the mechanical contact disconnector 16, the mechanical contact breaker 19 for the disconnector, and the mechanical contact disconnector 7 is given. First, when an open command is given to the mechanical contact breaker 19 for the disconnector, the H bridge circuit 21 discharges the electric charge of the capacitor 23, and the H bridge circuit 21 → commutation reactor 20 → mechanical contact breaker for the disconnector. Current is passed through 19 paths. Since this current flows in the direction opposite to the accident current, a zero point is generated, and the current can be interrupted by the mechanical contact breaker 19 for the disconnecting switch.

  When the mechanical contact breaker 19 for the disconnector is opened, the current suppression reactor 6 → the mechanical contact disconnector 16 → the H bridge circuit 21 → the commutation adjusting reactor 20 → the mechanical contact disconnector 7 → the path of the transmission line 2 The current commutates to. Next, the four IGBTs 22a to 22d constituting the H-bridge circuit 21 are gate-blocked, and the current is transferred to the path of the current suppression reactor 6 → the forward IGBT 11 → the forward thyristor 12 → the commutation adjusting reactor 20 → the transmission line 2. Let it flow. Then, the current of the mechanical contact disconnector 16 becomes zero, and the current interruption is completed. The subsequent operation is the same as in the third embodiment.

[4-3. effect]
In 4th Embodiment, in addition to the effect similar to 3rd Embodiment, by providing the mechanical contact-type circuit breaker 19 for disconnectors, it becomes possible to open the disconnector without using a semiconductor element, and at the time of power transmission Loss can be further reduced. In addition, as a commutation circuit in this embodiment, the thing of another structure can also be used if it is an inverter which can generate | occur | produce a current zero point other than the H bridge circuit 21 shown in figure.

[Fifth Embodiment]
[5-1. Constitution]
A fifth embodiment will be described with reference to FIG. The fifth embodiment is a commutation circuit in which the H-bridge circuit 21 of the fourth embodiment is replaced with a resonance generating circuit constituted by disconnector thyristors 24 a and 24 b and a capacitor 25.

[5-2. Action]
In the fifth embodiment, during power transmission, as in the fourth embodiment, the current suppression reactor 6 → the mechanical contact type disconnector 16 → the mechanical contact type circuit breaker 19 for the disconnector → the mechanical contact type disconnector 7 → the transmission line 2. Current is passed through the path and DC power is transmitted. Since the current does not pass through the semiconductor, it can be transmitted with high efficiency without causing any loss.

  When an accident occurs, first, by giving an open command to the disconnector thyristor 24a or 24b in order to open the mechanical contact breaker 19 for the disconnector, the charge of the capacitor 25 is discharged, and the capacitor 25 → commutation adjusting reactor. 20 → Current flows through the path of the mechanical contact breaker 19 for disconnector. Since this current path includes the inductance of the commutation reactor 20 and the capacitor 25, LC resonance occurs. As a result, a zero point is generated in the current, so that the current interruption by the mechanical contact breaker 19 for the disconnecting switch is interrupted. It becomes possible.

  After the zero point is generated in the mechanical contact breaker 19 for the disconnector, the disconnector thyristors 24a and 24b are turned off, and the current of the mechanical contact disconnector 16 is made zero, thereby opening the mechanical contact disconnector 16 open. Make it possible. The subsequent blocking operation is the same as in the fourth embodiment.

[5-3. effect]
In this embodiment, in addition to the effects of the fourth embodiment, the resonance generating circuit for opening the mechanical contact breaker 19 for the disconnecting switch can be configured with a thyristor having a large current withstand capability. There is an advantage that can be increased.

[6. Other Embodiments]
The embodiment of the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... DC voltage source 2 ... Transmission line 3 ... DC current interruption device 4 ... Accident point 5 ... Semiconductor breaker 6 ... Current suppression reactor 7 ... Mechanical contact type disconnector 8 ... Semiconductor element part 9 ... Arrester 10 ... Capacitor 11 ... Self Excited semiconductor device, forward IGBT
12 ... Forward thyristor 13 ... Diode 14 ... Reverse IGBT
15 ... Reverse thyristor 16 ... Mechanical contact type disconnect switch 17 ... Forward IGBT for disconnect switch
18 ... Reverse IGBT for disconnector
DESCRIPTION OF SYMBOLS 19 ... Mechanical contact-type circuit breaker 20 for disconnectors ... Commutation adjustment reactor 21 ... H bridge circuits 22a-22d ... IGBT
23 ... Capacitors 24a, 24b ... Circuit breaker thyristor 25 ... Capacitor

Claims (12)

A semiconductor element portion in which a forward self-excited semiconductor element and a forward thyristor are connected in series;
An arrester connected in parallel to the forward thyristor;
A semiconductor breaker in which the semiconductor element portion and the capacitor are connected in parallel;
A current suppressing reactor connected in series with the semiconductor breaker;
A mechanical contact disconnector or circuit breaker connected in series with the semiconductor breaker;
DC current interrupting device comprising.   2. The DC current interrupting device according to claim 1, wherein a withstand voltage of the forward self-excited semiconductor element is smaller than a withstand voltage of the forward thyristor.   3. The DC current interrupting device according to claim 2, wherein a reverse diode is connected in parallel to the forward thyristor. A reverse self-excited semiconductor element is connected in series to the forward self-excited semiconductor element,
4. The DC current interrupting device according to claim 3, wherein a thyristor in a reverse direction is connected in parallel to the thyristor in the forward direction to interrupt a bidirectional DC current.   5. The DC current interrupting device according to claim 1, wherein, when an accident occurs, the self-excited semiconductor element is turned off and the thyristor current is turned off by commutating the thyristor current to the capacitor. 6.   6. The DC current interrupting device according to claim 5, wherein the self-excited semiconductor element is turned on again immediately after the self-excited semiconductor element is turned off when an accident occurs.   The mechanical contact type disconnector is connected in parallel to the semiconductor circuit breaker, and a self-excited semiconductor element for opening the disconnector is connected in series to the mechanical contact type disconnector. The direct current interruption device according to item.   8. The DC current interrupting device according to claim 7, wherein when an accident occurs, the self-excited semiconductor element for opening the disconnector is turned off, the current of the mechanical contact disconnector is made zero, and the accident current is commutated to the semiconductor circuit breaker.   A mechanical contact disconnector and a commutation circuit are connected in parallel to the semiconductor circuit breaker, and between the mechanical contact disconnector and the contact of the commutation circuit and the mechanical contact disconnector or circuit breaker, The direct current according to any one of claims 1 to 6, wherein a mechanical contact breaker is connected, and a commutation adjusting reactor is connected between the semiconductor breaker and the mechanical contact breaker or breaker. Current interrupt device.   When an accident occurs, the commutation circuit generates a zero point in the mechanical contact circuit breaker to shut off the mechanical contact circuit breaker, the commutation circuit is turned off to make the current of the mechanical contact circuit breaker zero, The DC current interrupting device according to claim 9, wherein an accident current is commutated to the semiconductor circuit breaker.   The DC current interrupting device according to claim 9 or 10, wherein the commutation circuit is an inverter.   The DC current interrupting device according to claim 9 or 10, wherein the commutation circuit is a resonance generating circuit.

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