JP7446973B2 - DC current interrupter - Google Patents

Description

Embodiments of the present invention relate to a DC current interrupting device.

In recent years, studies and introduction of DC power transmission systems that transmit DC power have been progressing. Compared to conventional AC power transmission systems, DC power transmission systems can be installed at low cost when applied to long-distance high-power power transmission, and can construct a highly efficient system with less power transmission loss. On the other hand, in a DC power transmission system in which multiple power generation terminals are interconnected, it is difficult to shut off and isolate the location where a system fault has occurred. This is because with direct current, there is no point where the current crosses zero (zero point), so mechanical contacts cannot easily interrupt the current. In order to solve this problem, various DC current interrupting devices are being considered.

In a DC power transmission system that interconnects multiple power generation terminals, when an accident occurs on a DC transmission line, the faulty line is disconnected by opening the DC current breaker belonging to this DC transmission line, and power is transmitted using a healthy line. maintain. By the way, the DC current interrupting device maintains the conduction state of the DC transmission line under normal conditions, and operates to disconnect the faulty line only when an accident occurs on any DC transmission line, so it does not require special operation under normal conditions. There's nothing to do. Therefore, even if a failure occurs inside the DC current interrupting device and it is unable to perform normal interrupting operations, this will only be discovered when an accident occurs and the faulty line is interrupted. It's time to do something. If an internal failure is discovered when a DC current interrupting device is required to perform a cutoff operation, not only will it be impossible to properly cut off the faulty line, but the delay in stopping power transmission may make the accident worse or cause an accident. This can have various negative effects, such as the damage spreading to healthy lines or damage to equipment due to the accident. For this reason, it is necessary for the DC current interrupting device to have a mechanism that can quickly detect its own failure.

Japanese Patent Application Publication No. 2016-162713

The problem to be solved by the present invention is to provide a DC current interrupting device that can detect its own failure at an early stage and, in the event of a failure, promptly bring the device and system to a protective stop.

The DC current interrupting device of the embodiment includes a mechanical contact, a semiconductor circuit breaker, a commutation circuit, and a control device. Mechanical contacts are provided on DC power lines. A semiconductor circuit breaker is provided in parallel to the DC power transmission line. The commutation circuit commutates the current flowing through the mechanical contact during normal operation to the path passing through the semiconductor circuit breaker when the current is interrupted. A control device controls the mechanical contact, the semiconductor circuit breaker, and the commutation circuit. The control device operates the commutation circuit for a predetermined time and then stops the commutation circuit at an arbitrary timing during the steady state, and controls the commutation circuit based on the degree of change in the current flowing through the commutation circuit within the predetermined time. Determine whether there is an abnormality in the commutation circuit.

FIG. 1 is a diagram illustrating an example of the configuration of a DC current interrupting device according to a first embodiment. 1 is a diagram showing an example of the configuration of a semiconductor circuit breaker according to a first embodiment; FIG. FIG. 1 is a diagram showing an example of the configuration of a commutation circuit according to the first embodiment. The figure which shows an example of the flow of the electric current at the time of steady energization in the DC current interrupter of 1st Embodiment. FIG. 3 is a diagram showing an example of the flow of current at the time of failure determination in the DC current interrupting device of the first embodiment. The figure which shows an example of the waveform of the electric current which flows in the DC current interruption device of 1st Embodiment. The figure which shows an example of the structure of the DC current interruption device based on 2nd Embodiment. FIG. 7 is a diagram showing an example of the flow of current during steady energization in the DC current interrupting device of the second embodiment. FIG. 7 is a diagram showing an example of the flow of current at the time of failure determination in the DC current interrupting device according to the second embodiment. The figure which shows an example of the structure of the DC current interruption device based on 3rd Embodiment. The figure which shows an example of the structure of the commutation circuit of 3rd Embodiment. FIG. 7 is a diagram showing an example of the flow of current during steady energization in the DC current interrupting device of the third embodiment. FIG. 7 is a diagram illustrating an example of the flow of current at the time of failure determination in the DC current interrupting device according to the third embodiment. FIG. 7 is a diagram showing an example of a waveform of a current flowing in a DC current interrupting device according to a third embodiment. The figure which shows an example of the structure of the commutation circuit with which the DC current interruption device based on 4th Embodiment is provided. The figure which shows an example of the waveform of the voltage in the commutation circuit with which the DC current interruption device of 4th Embodiment is provided. The figure which shows an example of the structure of the DC current interruption device based on 5th Embodiment.

Hereinafter, a DC current interrupting device according to an embodiment will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing an example of the configuration of a DC current interrupting device according to a first embodiment. FIG. 1 shows an example of a DC current interrupting device 1 configured at an intermediate position of a DC power transmission line LN. In the DC current interrupting device 1 shown in FIG. 1, for example, power transmission equipment exists on the left side, and consumers exist on the right side. In this case, direct current normally flows from the left side to the right side. The DC current interrupting device 1 includes, for example, a mechanical contact 10, a semiconductor circuit breaker 20, a commutation circuit 30, and a control device 100.

In the DC current interrupting device 1, a mechanical contact 10 is provided on the DC power transmission line LN. In the DC current interrupting device 1, a series circuit in which the semiconductor circuit breaker 20 and the commutation circuit 30 are connected is connected in parallel to the DC power transmission line LN. More specifically, in a series circuit in which the second end d of the semiconductor circuit breaker 20 and the first end e of the commutation circuit 30 are connected to the first pole a side of the mechanical contact 10 in the DC power transmission line LN. The first end c of the semiconductor circuit breaker 20 is connected, and the second end f of the commutation circuit 30 in the series circuit is connected to the second pole b side of the mechanical contact 10. In the DC current interrupting device 1, a current detector 51 is attached to the second end f side of the commutation circuit 30, and a current detector 52 is attached to the second pole b side of the mechanical contact 10. During normal (steady) power transmission in the DC current interrupting device 1 , current flows through the mechanical contacts 10 . The current detector 51 and the current detector 52 may be installed at positions different from those shown in FIG. 1 as long as they are on the line between the series circuit and the mechanical contact 10, respectively. In FIG. 1, in order to show the current flowing through the entire DC current interrupting device 1, a current detector is placed on the right side of the intersection where the second pole b of the mechanical contact 10 and the second end f of the commutation circuit 30 are connected. Although a configuration in which a current detector 53 is attached is shown, the current detector 53 does not need to be attached to the DC current interrupting device 1.

The mechanical contact 10 is a mechanical contact type switch. The mechanical contact 10 includes one or more mechanical contact switches. The mechanical contact 10 is not limited to the configuration of a mechanical contact type switch, but may be configured of a disconnector or circuit breaker, or even a configuration in which a mechanical contact type switch and a disconnector or circuit breaker are mixed. good. The mechanical contact type switch is controlled by the control device 100 to be in either an open state or a closed state. With these configurations, the mechanical contact 10 can be connected between the first pole a and the second pole b according to the control by the control device 100 to open or close the mechanical contact switch. Allow or block (block) current flowing.

The semiconductor circuit breaker 20 allows or blocks (blocks) current flowing between the first end c and the second end d. FIG. 2 is a diagram showing an example of the configuration of the semiconductor circuit breaker 20 of the first embodiment. The semiconductor circuit breaker 20 includes, for example, a series circuit of a plurality of semiconductor switch sections 202 (only two semiconductor switch sections 202-1 and 202-2 are shown in FIG. 2) connected in series in the same direction. , arrester 204 are connected in parallel. Each of the semiconductor switch sections 202 includes, for example, a semiconductor switching element and a diode that are connected in parallel to each other. More specifically, in the semiconductor switch section 202, the cathode of the diode and the collector of the semiconductor switching element are connected to each other, and the anode of the diode and the emitter of the semiconductor switching element are connected to each other. The gate of the semiconductor switching element is controlled (a control voltage is applied) by the control device 100. That is, the semiconductor switch unit 202 is controlled by the control device 100 to be either on or off. The semiconductor switching element is, for example, a switching element such as an insulated gate bipolar transistor (IGBT). The semiconductor switching element is not limited to an IGBT, and may be any switching element as long as it is a semiconductor switching element that can realize self-extinguishing. The arrester 204 consumes (absorbs) surge energy generated due to the energy of the inductance of the DC power transmission line LN when the plurality of semiconductor switch units 202 included in the series circuit of the semiconductor switch units 202 are controlled to be off. )do. With this configuration, the semiconductor circuit breaker 20 controls the current flowing between the first terminal c and the second terminal d in accordance with the control by the control device 100 to turn the semiconductor switch unit 202 on or off. Allow or prevent (block).

The commutation circuit 30 transfers (commutates) the current flowing through the mechanical contact 10 to the semiconductor circuit breaker 20 . FIG. 3 is a diagram showing an example of the configuration of the commutation circuit 30 of the first embodiment. FIGS. 3A and 3B show an example of a commutation circuit 30 including an H-bridge circuit in which a semiconductor element and a voltage source are connected to each other. The commutation circuit 30a shown in FIG. 3A is, for example, a bidirectional H-bridge circuit in which four semiconductor switch sections 302 (semiconductor switch sections 302-1 to 302-4) and one capacitor 304 are connected to each other. It is composed of. The commutation circuit 30b shown in FIG. 3(b) includes, for example, two semiconductor switch sections (semiconductor switch sections 302-1 and 302-2), two diodes (diodes 306-1 and 306-2), and It is constructed from a unidirectional H-bridge circuit in which one capacitor 304 is connected to each other. The commutation circuit 30b has a configuration in which the semiconductor switch section 302-3 in the commutation circuit 30b is replaced with a diode 306-1, and the semiconductor switch section 302-4 is replaced with a diode 306-2.

Like the semiconductor switch section 202 included in the semiconductor circuit breaker 20, the semiconductor switch section 302 includes, for example, a semiconductor switching element and a diode that are connected in parallel to each other. More specifically, in the semiconductor switch section 302, the cathode of the diode and the collector of the semiconductor switching element are connected to each other, and the anode of the diode and the emitter of the semiconductor switching element are connected to each other. The gate of the semiconductor switching element is controlled (a control voltage is applied) by the control device 100. That is, the semiconductor switch section 302 is controlled to be either on or off by the control device 100, similarly to the semiconductor switch section 202 included in the semiconductor circuit breaker 20. The semiconductor switching element is, for example, a switching element such as an insulated gate bipolar transistor (IGBT), like the semiconductor switching element of the semiconductor switch section 202 included in the semiconductor circuit breaker 20. However, the semiconductor switching element included in the semiconductor switch section 302 may have a lower breakdown voltage than the semiconductor switching element of the semiconductor switch section 202 included in the semiconductor circuit breaker 20. The semiconductor switching element is not limited to an IGBT, and may be any switching element as long as it is a semiconductor switching element that can realize self-extinguishing. With this configuration, the commutation circuit 30 transfers the current flowing through the mechanical contact 10 to the semiconductor circuit breaker 20 in response to the control by the control device 100 to turn the semiconductor switch unit 302 on or off. commutation). Capacitor 304 is an example of an "energy storage element" in the claims. The configuration of either the commutation circuit 30a or the commutation circuit 30b shown in FIG. 3 is applied to the commutation circuit 30.

Current detector 51, current detector 52, and current detector 53 each detect current in the attached path. Each of the current detector 51, the current detector 52, and the current detector 53 outputs information representing a detected value (current value) of the detected current to the control device 100. More specifically, the current detector 51 outputs information on the current value of the detected current I51 to the control device 100, and the current detector 52 outputs information on the current value of the detected current I52 to the control device 100. The current detector 53 outputs information on the current value of the detected current I53 to the control device 100.

The control device 100 controls the interruption and conduction of the DC power transmission line LN in the DC current interruption device 1 by controlling the mechanical contacts 10, the semiconductor circuit breaker 20, and the commutation circuit 30. The control device 100 detects an abnormality (failure) in the commutation circuit 30 or the semiconductor circuit breaker 20 based on information on the current value output by the current detector 51 or the current detector 52 during a steady power transmission state. do. When the control device 100 detects a failure in the commutation circuit 30 or the semiconductor circuit breaker 20, it outputs a failure signal Sf representing this and notifies the higher-level control device (upper-level control device). For example, in a DC power transmission system including the DC current interrupting device 1, the host control device issues an instruction to interrupt the DC power transmission line LN, an instruction to bring the DC power transmission system to a protective stop, etc. to the DC current interrupting device 1. This is a management device that instructs the operation of the DC current interrupting device 1.

The control device 100 realizes the following functions by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of the functions of the control device 100 are implemented using hardware (circuit units) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and GPU (Graphics Processing Unit). ; circuitry), or may be realized by collaboration between software and hardware. Some or all of the functions of the control device 100 may be realized by a dedicated LSI. The program may be stored in advance in a storage device (a storage device including a non-transitory storage medium) such as an HDD (Hard Disk Drive) or a flash memory included in the control device 100, or may be stored in a storage device such as a DVD, CD-ROM, etc. The storage medium is stored in a removable storage medium (non-transitory storage medium), and may be installed in the storage device of the control device 100 by attaching the storage medium to the drive device of the control device 100. .

With such a configuration, in the DC current interrupting device 1, if an accident occurs in the DC power transmission line LN, the DC power transmission line LN where the accident has occurred is interrupted. Further, in the DC current interrupting device 1, a failure of the commutation circuit 30 or the semiconductor circuit breaker 20 provided in the DC current interrupting device 1 itself is detected at an early stage, and when a failure is detected, a failure signal indicating that a failure has been detected is sent. Sf is output and notified to the higher-level control device. As a result, in a DC power transmission system including the DC current interrupting device 1, the host control device can issue an instruction to the DC current interrupting device 1 to promptly stop the DC current interrupting device 1 or the DC power transmission system for protection. .

The configuration of the DC current interrupting device 1 is not limited to the configurations shown in FIGS. 1 to 3. For example, a configuration may be adopted in which an auxiliary disconnector is connected to the DC transmission line LN, and a DC reactor is installed in each DC transmission line LN to suppress changes in current in the event of an accident. It may also be configured such that it is connected to.

[Operation of interrupting DC power line LN in DC current interrupting device 1]
In the DC current interrupting device 1, during a steady power transmission state in which power is transmitted through the DC power transmission line LN, the mechanical contact 10 is in a closed state, and the semiconductor circuit breaker 20 and commutation circuit 30 are in an OFF state. In this case, in the DC current interrupting device 1, as shown in FIG. 4, the power transmission line current Idc is caused to flow from the left side to the right side of the DC power transmission line LN. The power transmission line current Idc is a current flowing through the entire DC current interrupting device 1, and is a detection current I53 detected by the current detector 53. Here, for example, if an accident occurs in the DC power transmission line LN, the control device 100 shuts off the DC power transmission line LN using the following procedure.

When an accident occurs in the DC power transmission line LN, the control device 100 first opens the mechanical contact 10. If only the mechanical contacts 10 are brought into an open state, an arc will be generated between the contacts of the mechanical contacts 10, so that the DC power transmission line LN will not be electrically interrupted. Therefore, the control device 100 turns on the commutation circuit 30 and also turns on the semiconductor circuit breaker 20. Then, the charge in the capacitor 304 included in the commutation circuit 30 is discharged, a current flows in the opposite direction to the mechanical contact 10, and the current in the DC power transmission line LN is commutated from the commutation circuit 30 to the semiconductor circuit breaker 20. It becomes like this. As a result, a current zero point occurs in the mechanical contact 10, and no further current flows. The timing at which the mechanical contact 10 is opened may be the timing after the current zero point occurs. After that, the control device 100 turns the semiconductor circuit breaker 20 off. As a result, in the DC current interrupting device 1, surge energy corresponding to the inductance of the DC power transmission line LN is consumed by the arrester 204 included in the semiconductor circuit breaker 20. That is, the DC current interrupting device 1 interrupts the current of the DC power transmission line LN. Through such a procedure, the DC current interrupting device 1 controlled by the control device 100 electrically interrupts the DC power transmission line LN in which the accident has occurred.

[Operation for detecting failure in DC current interrupting device 1]
Next, an example of an operation in which the control device 100 in the DC current interrupting device 1 detects a failure in the commutation circuit 30 (including the semiconductor circuit breaker 20) will be described. FIG. 5 is a diagram showing an example of the flow of current during failure determination in the DC current interrupting device 1 of the first embodiment. FIG. 6 is a diagram showing an example of the waveform of the current flowing in the DC current interrupting device 1 of the first embodiment. In the following description, the operation of detecting a failure in the commutation circuit 30 in the DC current interrupting device 1 will be explained with reference to FIGS. 4 to 6 as appropriate.

In the DC current interrupting device 1, the control device 100 controls the commutation circuit by controlling the opening, closing, on, and off of each component for a short predetermined time (short time) during a steady power transmission state. 30 failures detected. At this time, in the DC current interrupting device 1, a commutation current Ic flows through the semiconductor circuit breaker 20 and the commutation circuit 30, as shown in FIG. The commutation current Ic is a detection current I51 detected by the current detector 51. The control device 100 detects (determines) a failure of the commutation circuit 30 based on the degree of temporal change in the current value of the commutation current Ic. During the predetermined short time period during which the control device 100 controls each component, the degree of temporal change in the current value of the commutation current Ic is determined without affecting the steady power transmission state in the DC current interrupting device 1. It's time to do it. The predetermined short time may be determined in advance based on the configuration and specifications of the commutation circuit 30 and the semiconductor circuit breaker 20, for example.

The initial state when starting the operation to detect a failure in the DC current interrupting device 1 is a steady power transmission state. Therefore, as shown in FIG. be. In the DC current interrupting device 1, the control device 100 starts an operation to detect a failure at an arbitrary timing. The arbitrary timing is, for example, based on the current value of the transmission line current Idc flowing through the DC transmission line LN and the commutation circuit 30 assumed when the commutation circuit 30 is operated for a predetermined short time to detect a failure. This is the timing at which the rated value of the DC current interrupting device 1 is not exceeded based on the amount of change in the current flowing through the DC current interrupting device 1. The assumed amount of change in the current of the commutation circuit 30 is a predetermined current value threshold for determining whether the commutation circuit 30 is out of order. The threshold value of the current value is determined based on, for example, the energy potential of the commutation circuit 30 and the impedance of the line parallel to the DC transmission line LN passing through the semiconductor circuit breaker 20 and the commutation circuit 30 in a steady power transmission state. It is calculated and set in advance from the current value. When the assumed amount of change in the current (threshold current value) of the commutation circuit 30 is set as the "current threshold Ia", the control device 100 controls, for example, when the current value of the power transmission line current Idc is lower than the rated value, the current threshold Ia. An arbitrary timing is when the current value of the power transmission line current Idc is higher than or equal to the current threshold value Ia. In other words, in the DC current interrupting device 1, the timing is set such that at least the current threshold value Ia can be secured as a margin so that each current value that changes when performing an operation to detect a failure does not exceed the rated value. , an arbitrary timing for performing an operation to detect a failure.

The control device 100 detects a failure in the commutation circuit 30 (including the semiconductor circuit breaker 20) by executing the following procedure at an arbitrary timing in a steady power transmission state.

(Procedure 1-1): When the control device 100 starts the operation of detecting a failure, first, the semiconductor circuit breaker 20 is turned on while the mechanical contact 10 remains closed, and then the commutation circuit 30 is turned on. turn on. As a result, the charge in the capacitor 304 included in the commutation circuit 30 is discharged, and a commutation current Ic begins to flow through the semiconductor circuit breaker 20 and the commutation circuit 30 as shown in FIG.

(Step 1-2): Then, the control device 100 controls the operation of the commutation circuit 30 and the semiconductor circuit breaker 20 based on the current value of the commutation current Ic outputted by the current detector 51 and the current threshold value Ia. It is determined whether there is an abnormality, that is, whether the commutation circuit 30 or the semiconductor circuit breaker 20 is out of order. The control device 100 determines whether the commutation circuit 30 or the semiconductor circuit breaker 20 is out of order based on the degree of temporal change in the current value of the commutation current Ic. In FIG. 6, when the current value of the power transmission line current Idc is lower than the rated current value Irated by more than the current threshold value Ia, the current value of the commutation current Ic is The figure shows an example of a case where In FIG. 6, at time T2 when a predetermined short time has passed, the degree of change in the current value of commutated current Ic from time T1 (more specifically, the degree of change in the current value of commutated current Ic from time T1) is shown. difference) exceeds the current threshold Ia. In this case, the control device 100 determines that there is no operational abnormality in the commutation circuit 30 or the semiconductor circuit breaker 20 (no failure). The control device 100 may or may not output a failure signal Sf indicating that it has been determined that the commutation circuit 30 and the semiconductor circuit breaker 20 are not in failure. That is, if the commutation circuit 30 or the semiconductor circuit breaker 20 is not out of order, the control device 100 may or may not notify the higher-level control device. For example, if the operation to detect the current failure is performed according to a preset periodic timing, there is no need to notify the higher-level control device of the failure detection result. If the action is performed in response to an instruction from a higher-level control device, the higher-level control device is notified of the failure detection result. On the other hand, at time T2, if the difference from the current value of the commutation current Ic at time T1 is less than or equal to the current threshold Ia, the control device 100 determines that there is an abnormality in the operation of the commutation circuit 30 or the semiconductor circuit breaker 20. It is determined that the device is malfunctioning. In this case, the control device 100 detects the commutation circuit regardless of whether the operation to detect the current failure is performed according to regular timing or in response to an instruction from the higher-level control device. 30 or the semiconductor circuit breaker 20 is determined to be malfunctioning, and outputs a failure signal Sf to notify the higher-level control device.

The timing at which the control device 100 determines whether or not there is an operational abnormality in the commutation circuit 30 or the semiconductor circuit breaker 20 is not limited to the timing at time T2 when the predetermined short time described above has elapsed. For example, the control device 100 samples the current value of the commutated current Ic at predetermined time intervals up to time T2, and determines the degree of change in the current value of the commutated current Ic from time T1 to the sampling time (more specifically, Specifically, there is an abnormality in the operation of the commutation circuit 30 or the semiconductor circuit breaker 20 based on the difference between the current value of the commutation current Ic at time T1 and the current value of the sampled commutation current Ic. It may be determined whether or not. In this case, the commutation circuit 30 and the semiconductor circuit breaker 20 fail when the difference between the current value of the commutation current Ic at time T1 and the current value of the sampled commutation current Ic exceeds the current threshold value Ia. It can be determined that the That is, the control device 100 can determine that the commutation circuit 30 and the semiconductor circuit breaker 20 are not out of order without waiting for the elapse of time T2. On the other hand, if the difference between the current value of the commutation current Ic at time T1 and the current value of the commutation current Ic sampled at time T2 is equal to or less than the current threshold value Ia at the timing when time T2 has elapsed, the control The device 100 determines that the commutation circuit 30 and the semiconductor circuit breaker 20 have an operational abnormality (failure).

(Step 1-3): After that (for example, when time T2 has elapsed or when it is determined that the commutation circuit 30 or the semiconductor circuit breaker 20 has not failed), the control device 100 starts the commutation circuit 30. Then, the semiconductor circuit breaker 20 is turned off. In FIG. 6, the current value of the commutated current Ic starts to decrease as the control device 100 executes step 1-3 at time T2, and the current value of the commutated current Ic becomes zero at time T3, that is, the series circuit An example of a case where the original state (steady power transmission state) in which no commutation current Ic flows through (the semiconductor circuit breaker 20 and the commutation circuit 30) is shown is shown.

Through such a procedure, the control device 100 operates the commutation circuit 30 and the semiconductor circuit breaker 20 for a predetermined short time when the DC current interrupting device 1 is in a steady power transmission state. or a failure of the semiconductor circuit breaker 20 is detected.

As shown in FIG. 6, the mechanical contact detected by the current detector 52 as the current value of the commutation current Ic starts to increase from time T1 due to the control device 100 executing step 1-1. The current value of the detection current I52 flowing through 10 has started to decrease. Therefore, the control device 100 determines whether the commutation circuit 30 or the semiconductor circuit breaker 20 is out of order based on the degree of change in the current value of the detection current I52 instead of the above-described current value of the commutation current Ic. may be determined. In this case, the control device 100 controls whether the commutation circuit 30 or the semiconductor circuit breaker 2 Determine whether or not there is an abnormality in operation (whether or not there is a failure). For example, if the difference between the current value of the detected current I52 at time T1 at time T2 exceeds the current threshold value Ia, the control device 100 determines that there is no malfunction in the commutation circuit 30 or the semiconductor circuit breaker 20. If the current is less than or equal to the current threshold value Ia, it is determined that the commutation circuit 30 or the semiconductor circuit breaker 20 has an operational abnormality (faulty). In this case as well, the control device 100 may sample the current value of the detection current I52 at predetermined time intervals between time T1 and time T2 to determine the failure of the commutation circuit 30 or the semiconductor circuit breaker 20. good.

With such a configuration and procedure, in the DC current interrupting device 1, the control device 100 detects a failure in the commutation circuit 30 or the semiconductor circuit breaker 20. As a result, the DC current interrupting device 1 can detect a failure in the commutation circuit 30 or the semiconductor circuit breaker 20 at an early stage, and if there is a failure in the commutation circuit 30 or the semiconductor circuit breaker 20, the host controller However, the DC current interrupting device 1 and the DC power transmission system can be immediately brought to a protective stop. As a result, the DC current interrupting device 1 ensures (guarantees) that the commutation circuit 30 and the semiconductor circuit breaker 20 operate normally, and even if an accident occurs in the DC transmission line LN, the accident will not occur. The DC power transmission line LN can be normally shut off. Moreover, in the DC current interrupting device 1, as shown in FIG. 6, the power transmission line current Idc flowing through the entire DC current interrupting device 1 hardly changes. This is because the power transmission line current Idc is the sum of the commutation current Ic and the detection current I52, and since the DC power transmission line LN has inductance, the power transmission current Idc does not change immediately. Therefore, in the DC current interrupting device 1, even if an operation to detect a failure of the commutation circuit 30 or the semiconductor circuit breaker 20 is performed, there is almost no effect on the steady power transmission state.

As explained above, according to the DC current interrupting device 1 of the first embodiment, by detecting a failure of the DC current interrupting device 1 itself at an early stage and notifying the higher-level control device, if there is a failure, Devices and systems can be immediately brought to a protective stop.

(Second embodiment)
The second embodiment will be described below. FIG. 7 is a diagram showing an example of the configuration of a DC current interrupting device according to the second embodiment. In FIG. 7, components having functions common to those of the DC current interrupting device 1 of the first embodiment are given the same reference numerals. The DC current interrupting device 2 includes, for example, a mechanical contact 10A, a mechanical contact 10B, a semiconductor circuit breaker 20, a commutation circuit 30, and a control device 100. The DC current interrupting device 2 is also a DC current interrupting device configured at an intermediate position of the DC power transmission line LN, similarly to the DC current interrupting device 1 of the first embodiment. Therefore, in the DC current interrupting device 2, for example, power transmission equipment exists on the left side and consumers exist on the right side, and during normal (steady) power transmission, DC current flows from the left side to the right side.

In the DC current interrupting device 2, a mechanical contact 10A and a mechanical contact 10B are connected in series to the DC power transmission line LN. More specifically, in the DC power transmission line LN, the second pole bA of the mechanical contact 10A and the first pole aB of the mechanical contact 10B are connected. In the DC current interrupting device 2, the first end c of the semiconductor circuit breaker 20 is connected to the first pole a-A side of the mechanical contact 10A in the DC transmission line LN, and the first end c of the semiconductor circuit breaker 20 is connected to the second pole b-A of the mechanical contact 10A. The first end e of the commutation circuit 30 is connected to the DC power transmission line LN between the first pole a-B of the mechanical contact 10B, and the first end e of the commutation circuit 30 is connected to the second pole b-B of the mechanical contact 10B. , the second end d of the semiconductor circuit breaker 20 and the second end f of the commutation circuit 30 are connected. In the DC current interrupting device 2, a current detector 51 is attached to the second end f side of the commutation circuit 30, and a current detector 52 is attached to the second pole b-A side of the mechanical contact 10A. . During normal (steady) power transmission in the DC current interrupting device 2, current flows through the mechanical contacts 10A and 10B. The current detector 51 and the current detector 52 may be attached to positions different from those shown in FIG. 7 as long as they are on the line between the commutation circuit 30 and the mechanical contact 10, respectively. In FIG. 7, in order to show the current flowing through the entire DC current interrupting device 2, the second pole b-B of the mechanical contact 10B, the second end d of the semiconductor circuit breaker 20, and the second terminal d of the commutation circuit 30 are shown. Although a configuration is shown in which the current detector 53 is attached to the right side of the intersection where the end f is connected, the current detector 53 does not need to be attached to the DC current interrupting device 2.

Mechanical contact 10A and mechanical contact 10B are mechanical contact type switches. For example, the mechanical contact 10A may be a disconnector, and the mechanical contact 10B may be a circuit breaker. Also in the DC current interrupting device 2, the semiconductor circuit breaker 20 has the configuration shown in FIG. 2, and the commutation circuit 30 has the configuration of either the commutation circuit 30a or the commutation circuit 30b shown in FIG. applies. The mechanical contact 10A is an example of a "first mechanical contact" in the claims, and the mechanical contact 10B is an example of a "second mechanical contact" in the claims.

Similarly to the DC current interrupter 1 of the first embodiment, the DC current interrupter 2 may also have a configuration in which, for example, an auxiliary disconnector is connected to the DC power transmission line LN. A configuration may be adopted in which a DC reactor for suppressing a change in current in such a case is connected in the line of each DC power transmission line LN.

With such a configuration, in the DC current interrupting device 2 as well, in the same way as the DC current interrupting device 1 of the first embodiment, if an accident occurs in the DC power transmission line LN, the DC current interrupting device 2 cut off. Furthermore, the DC current interrupting device 2 detects a failure in the commutation circuit 30 included in the DC current interrupting device 2 itself at an early stage, and when a failure is detected, sends information indicating that a failure has been detected to a failure signal Sf. Notify the higher-level control device by outputting. As a result, even in a DC power transmission system equipped with the DC current interrupting device 2, the host control device can issue an instruction to the DC current interrupting device 2 to promptly stop the DC current interrupting device 2 or the DC power transmission system for protection. .

[Operation of interrupting DC power line LN in DC current interrupting device 2]
In the DC current interrupting device 2, during a steady power transmission state in which power is transmitted by the DC transmission line LN, the mechanical contacts 10A and 10B are each in a closed state, and the semiconductor circuit breaker 20 and the commutation circuit 30 is in the off state. In this case, in the DC current interrupting device 2, as shown in FIG. 8, the power transmission line current Idc is caused to flow from the left side to the right side of the DC power transmission line LN. The power transmission line current Idc is a current flowing through the entire DC current interrupting device 2, and is a detection current I53 detected by the current detector 53. Here, for example, if an accident occurs in the DC power transmission line LN, the control device 100 shuts off the DC power transmission line LN using the following procedure.

When an accident occurs in the DC power transmission line LN, the control device 100 first opens the mechanical contacts 10A and 10B. If only the mechanical contacts 10A and 10B are opened, an arc will occur between the mechanical contacts 10A and 10B, and the direct current transmission line LN will be electrically disconnected. It will not be in a state where it is blocked off. Therefore, by first turning on the commutation circuit 30, the control device 100 cancels the current of the mechanical contact 10B by discharging the electric charge of the capacitor 304 included in the commutation circuit 30. Extinguishes the arc between contacts. Thereafter, the control device 100 turns on the semiconductor circuit breaker 20 and turns off the commutation circuit 30, thereby commutating the current of the DC power transmission line LN from the commutation circuit 30 to the semiconductor circuit breaker 20. , the arc between the mechanical contacts 10A is extinguished. Finally, the control device 100 turns the semiconductor circuit breaker 20 off. Thereby, in the DC current interrupting device 2, the surge energy corresponding to the inductance of the DC power transmission line LN is consumed by the arrester 204 included in the semiconductor circuit breaker 20, and the current of the DC power transmission line LN is interrupted. Through such a procedure, the DC current interrupting device 2 controlled by the control device 100 electrically interrupts the DC power transmission line LN in which the accident has occurred.

[Operation to detect failure in DC current interrupting device 2]
Next, an example of the operation of the control device 100 in the DC current interrupting device 2 to detect a failure in the commutation circuit 30 will be described. FIG. 9 is a diagram showing an example of the flow of current during failure determination in the DC current interrupting device 2 of the second embodiment. The waveform of the current flowing when determining a failure in the DC current interrupting device 2 is similar to the waveform of the current flowing when determining a failure in the DC current interrupting device 1 of the first embodiment shown in FIG. Therefore, in the following description, the operation of detecting a failure in the commutation circuit 30 in the DC current interrupting device 2 will be explained with reference to FIGS. 8, 9, and 6 as appropriate.

In the DC current interrupting device 2, similarly to the DC current interrupting device 1 of the first embodiment, the control device 100 controls opening and closing of each component for a predetermined short period of time during a steady power transmission state. , ON, and OFF to detect a failure in the commutation circuit 30. At this time, in the DC current interrupting device 2, as shown in FIG. A failure of the circuit 30 is detected (determined). The concept of a predetermined short time period in which the control device 100 controls each component, the concept of arbitrary timing, and the method of judgment when detecting a failure in the commutation circuit 30 are based on the DC current of the first embodiment. This is similar to the blocking device 1. Therefore, a detailed explanation of these methods will be omitted.

The initial state when starting the operation to detect a failure in the DC current interrupting device 2 is a steady power transmission state, so the power transmission line current Idc is flowing through the DC transmission line LN as shown in FIG. be. In the DC current interrupting device 2, the control device 100 detects a failure in the commutation circuit 30 by executing the following procedure at an arbitrary timing in a steady power transmission state.

(Procedure 2-1): When the control device 100 starts the operation to detect a failure, first, it closes the mechanical contacts 10A and 10B, and while the semiconductor circuit breaker 20 remains off, the commutation occurs. The circuit 30 is turned on. As a result, the charge in the capacitor 304 included in the commutation circuit 30 is discharged, and a commutation current Ic starts flowing through the commutation circuit 30 as shown in FIG.

(Step 2-2): Then, the control device 100 determines whether or not the operation of the commutation circuit 30 is abnormal based on the current value of the commutation current Ic outputted by the current detector 51 and the current threshold value Ia. (whether or not it is malfunctioning). That is, in the DC current interrupting device 2 as well, the control device 100 determines whether the commutation circuit 30 is out of order based on the degree of change over time in the current value of the commutation current Ic. At this time, if the waveform of the current flowing through the commutation circuit 30 is the current waveform shown in FIG. 6, the control device 100 makes the same determination as the DC current interrupting device 1 of the first embodiment. Then, the control device 100 outputs a fault signal Sf representing the determined result, and notifies the higher-level control device of the fault detection result.

(Step 2-3): After that, the control device 100 turns off the commutation circuit 30. As a result, the current value of the commutation current Ic in the DC current interrupting device 2 also returns to its original state (steady power transmission state) (see FIG. 6).

Through such a procedure, the control device 100 detects a failure in the commutation circuit 30 by operating the commutation circuit 30 for a predetermined short time when the DC current interrupting device 2 is in a steady power transmission state. . Similarly to the DC current interrupting device 1 of the first embodiment, the DC current interrupting device 2 also performs switching based on the degree of change in the current value of the detected current I52 flowing through the mechanical contact 10 detected by the current detector 52. It may also be determined whether the flow circuit 30 is out of order.

With such a configuration and procedure, in the DC current interrupting device 2, the control device 100 detects a failure in the commutation circuit 30. As a result, the DC current interrupting device 2 can detect a failure in the commutation circuit 30 at an early stage, and if there is a failure in the commutation circuit 30, the host control device can promptly detect the failure in the DC current interrupting device 2 or The DC power transmission system can be brought to a protective stop. As a result, the DC current interrupting device 2 ensures (guarantees) that the commutation circuit 30 operates normally, and even if an accident occurs on the DC transmission line LN, the DC transmission line LN where the accident occurred will be removed. It can be shut off normally. Moreover, even in the DC current interrupting device 2, since the power transmission line current Idc flowing through the entire DC current interrupting device 2 hardly changes, the operation of detecting a fault in the commutation circuit 30 does not affect the steady power transmission state. do not have. Furthermore, in the DC current interrupting device 2, there is no need to operate the semiconductor circuit breaker 20 in order to detect a failure in the commutation circuit 30.

As explained above, according to the DC current interrupting device 2 of the second embodiment, by detecting a failure of the DC current interrupting device 2 itself at an early stage and notifying the higher-level control device, if there is a failure, Devices and systems can be immediately brought to a protective stop.

(Third embodiment)
The third embodiment will be described below. FIG. 10 is a diagram showing an example of the configuration of a DC current interrupting device according to the third embodiment. In FIG. 10, components having functions common to those of the DC current interrupting device 1 of the first embodiment are given the same reference numerals. The DC current interrupting device 3 includes, for example, a mechanical contact 10, a semiconductor circuit breaker 20, a commutation circuit 30, and a control device 100. The DC current interrupting device 3 is also a DC current interrupting device configured at an intermediate position of the DC power transmission line LN, similarly to the DC current interrupting device 1 of the first embodiment. Therefore, in the DC current interrupting device 3, for example, power transmission equipment exists on the left side and consumers exist on the right side, and during normal (steady) power transmission, DC current flows from the left side to the right side.

In the DC current interrupting device 3, a mechanical contact 10 and a commutation circuit 30 are connected in series to the DC power transmission line LN. More specifically, in the DC power transmission line LN, the second pole b of the mechanical contact 10 and the first end e of the commutation circuit 30 are connected. In the DC current interrupting device 3, the first end c of the semiconductor circuit breaker 20 is connected to the first pole a side of the mechanical contact 10 in the DC transmission line LN, and the semiconductor circuit breaker 20 is connected to the second end f side of the commutation circuit 30. The second end d of the circuit breaker 20 is connected. In the DC current interrupting device 3, a current detector 51 is attached to the second end d side of the semiconductor circuit breaker 20, and a current detector 52 is attached to the second end f side of the commutation circuit 30. During normal (steady) power transmission in the DC current interrupting device 3, current flows through the mechanical contacts 10 and the commutation circuit 30. The current detector 51 and the current detector 52 may be attached to positions different from those shown in FIG. 10 as long as they are on the line between the semiconductor circuit breaker 20 and the commutation circuit 30, respectively. In FIG. 10, in order to show the current flowing through the entire DC current interrupting device 3, a current detector is placed on the right side of the intersection where the second end d of the semiconductor circuit breaker 20 and the second end f of the commutation circuit 30 are connected. Although a configuration in which a current detector 53 is attached is shown, the current detector 53 does not need to be attached to the DC current interrupting device 3.

Also in the DC current interrupting device 3, the configuration of the semiconductor circuit breaker 20 is the configuration shown in FIG. In the DC current interrupting device 3, the configuration of the commutation circuit 30 is different from the DC current interrupting device 1 of the first embodiment and the DC current interrupting device 2 of the second embodiment. In the DC current interrupting device 3, the commutation circuit 30 is configured to allow or block (block) current flowing between the first end e and the second end f.

FIG. 11 is a diagram showing an example of the configuration of the commutation circuit 30 of the third embodiment. In the commutation circuit 30c shown in FIG. 11, a plurality of semiconductor switch sections 302 (only two semiconductor switch sections 302-5 and 302-6 are shown in FIG. 11) are connected in series in the same direction. The series circuit and arrester 308 are connected in parallel. The semiconductor switch sections 302 may be connected in parallel. The arrester 308 consumes (absorbs) surge energy generated due to the energy of the inductance of the mechanical contact 10 and the commutation circuit 30 when the semiconductor switch section 302 is controlled to be in the OFF state. However, the arrester 308 may also have a lower breakdown voltage than the arrester 204 included in the semiconductor circuit breaker 20. With this configuration, the commutation circuit 30 controls the current flowing between the first terminal e and the second terminal f in accordance with the control by the control device 100 to turn the semiconductor switch unit 302 on or off. Allow or prevent (block). In the DC current interrupting device 3, a commutation circuit 30c shown in FIG. 11 is applied as the commutation circuit 30.

Similarly to the DC current interrupter 1 of the first embodiment, the DC current interrupter 3 may also have a configuration in which, for example, an auxiliary disconnector is connected to the DC power transmission line LN. A configuration may be adopted in which a DC reactor for suppressing a change in current in such a case is connected in the line of each DC power transmission line LN.

With such a configuration, in the DC current interrupting device 3 as well, in the same way as the DC current interrupting device 1 of the first embodiment, if an accident occurs in the DC power transmission line LN, the DC current interrupting device 3 cut off. Furthermore, the DC current interrupting device 3 detects a failure of the commutation circuit 30 or the semiconductor circuit breaker 20 that the DC current interrupting device 3 itself is equipped with at an early stage, and when a failure is detected, provides information indicating that a failure has been detected. , and notifies the higher-level control device by outputting a failure signal Sf. As a result, even in a DC power transmission system equipped with the DC current interrupting device 3, the host control device can issue an instruction to the DC current interrupting device 3 to promptly stop the DC current interrupting device 3 or the DC power transmission system for protection. .

[Operation of interrupting DC power line LN in DC current interrupting device 3]
In the DC current interrupting device 3, during a steady power transmission state in which power is transmitted by the DC transmission line LN, the mechanical contact 10 is in a closed state, the commutation circuit 30 is in an on state, and the semiconductor circuit breaker 20 is in an on state. It is off. In this case, in the DC current interrupting device 3, as shown in FIG. 12, the power transmission line current Idc is caused to flow from the left side to the right side of the DC power transmission line LN. The power transmission line current Idc is a current flowing through the entire DC current interrupting device 3, and is a detection current I53 detected by the current detector 53. Here, for example, if an accident occurs in the DC power transmission line LN, the control device 100 shuts off the DC power transmission line LN using the following procedure.

When an accident occurs in the DC power transmission line LN, the control device 100 first opens the mechanical contacts 10 and turns the semiconductor circuit breaker 20 on. Even in this case, since an arc occurs between the contacts of the mechanical contacts 10, the DC power transmission line LN is not electrically interrupted. Therefore, the control device 100 turns the commutation circuit 30 off. Thereby, the current of the DC power transmission line LN is commutated from the mechanical contact 10 to the semiconductor circuit breaker 20, and the arc between the contacts of the mechanical contact 10 is extinguished. After that, the control device 100 turns the semiconductor circuit breaker 20 off. As a result, in the DC current interrupting device 3, the surge energy corresponding to the inductance of the DC power transmission line LN is consumed by the arrester 204 included in the semiconductor circuit breaker 20, and the current of the DC power transmission line LN is interrupted. Through such a procedure, the DC current interrupting device 3 controlled by the control device 100 electrically interrupts the DC power transmission line LN in which the accident has occurred.

[Operation to detect failure in DC current interrupting device 3]
Next, an example of the operation of the control device 100 in the DC current interrupting device 3 to detect a failure of the commutation circuit 30 (including the semiconductor circuit breaker 20) will be described. FIG. 13 is a diagram illustrating an example of the flow of current at the time of failure determination in the DC current interrupting device 3 of the third embodiment. FIG. 14 is a diagram showing an example of the waveform of the current flowing in the DC current interrupting device 3 of the third embodiment. In the following description, the operation of detecting a failure in the commutation circuit 30 in the DC current interrupting device 3 will be explained with reference to FIGS. 12 to 14 as appropriate.

In the DC current interrupting device 3, similarly to the DC current interrupting device 1 of the first embodiment, the control device 100 controls the opening and closing of each component for a predetermined short period of time during a steady power transmission state. , ON, and OFF to detect failures in the commutation circuit 30 and the semiconductor circuit breaker 20. At this time, in the DC current interrupting device 3, as shown in FIG. A failure of the circuit 30 or the semiconductor circuit breaker 20 is detected (determined). The concept of a predetermined short time period in which the control device 100 controls each component, the concept of arbitrary timing, and the method of judgment when detecting a failure of the commutation circuit 30 or the semiconductor circuit breaker 20 are as follows: This is the same as the DC current interrupting device 1 of the embodiment. Therefore, a detailed explanation of these methods will be omitted.

The initial state when starting the operation to detect a failure in the DC current interrupting device 3 is a steady power transmission state, so the power transmission line current Idc is flowing through the DC transmission line LN as shown in FIG. be. In the DC current interrupting device 3, the control device 100 detects a failure in the commutation circuit 30 (including the semiconductor circuit breaker 20) by executing the following procedure at an arbitrary timing in a steady power transmission state.

(Step 3-1): When the control device 100 starts the operation of detecting a failure, first, the semiconductor circuit breaker 20 is turned on while the mechanical contact 10 remains closed, and then the commutation circuit 30 is turned on. to the off state. As a result, the current in the DC power transmission line LN is diverted to the semiconductor circuit breaker 20, and a circuit breaker current Is begins to flow through the semiconductor circuit breaker 20 as shown in FIG. Even in this case, the power transmission line current Idc flowing through the entire DC current interrupting device 3 hardly changes. This means that the power transmission line current Idc is the sum of the circuit breaker current Is and the detection current I52 that passes through the mechanical contact 10 and the commutation circuit 30 detected by the current detector 52, and the DC power transmission line LN has an inductance. This is because the power transmission current Idc does not change immediately.

(Step 3-2): Then, the control device 100 controls the operation of the commutation circuit 30 and the semiconductor circuit breaker 20 based on the current value of the circuit breaker current Is outputted by the current detector 51 and the current threshold value Ia. Determine whether or not there is an abnormality (whether or not there is a failure). That is, in the DC current interrupting device 3, the control device 100 determines whether the commutation circuit 30 or the semiconductor circuit breaker 20 is out of order based on the degree of change over time in the current value of the circuit breaker current Is. . In FIG. 14, when the current value of the transmission line current Idc is lower than the rated current value Irated by more than the current threshold value Ia, the current value of the circuit breaker current Is is shown as a result of the control device 100 executing step 3-1 at time T1. The figure shows an example of a case where In FIG. 14, at time T2 after a predetermined short time, the degree of change in the current value of the circuit breaker current Is from time T1 (more specifically, the degree of change in the current value of the circuit breaker current Is from time T1) is shown. difference) exceeds the current threshold Ia. In this case, the control device 100 determines that there is no operational abnormality in the commutation circuit 30 or the semiconductor circuit breaker 20 (no failure), similarly to the DC current interrupting device 1 of the first embodiment. On the other hand, at time T2, if the difference between the current value of the circuit breaker current Is and the current value at time T1 is equal to or less than the current threshold value Ia, the control device 100 similarly to the DC current interrupting device 1 of the first embodiment, It is determined that the commutation circuit 30 or the semiconductor circuit breaker 20 has an abnormal operation (is out of order). Then, the control device 100 outputs a fault signal Sf representing the determined result, and notifies the higher-level control device of the fault detection result.

(Step 3-3): After that (for example, when time T2 has elapsed, or when it is determined that the commutation circuit 30 or the semiconductor circuit breaker 20 is not out of order), the control device 100 starts the commutation circuit 30. The semiconductor circuit breaker 20 is turned on, and then the semiconductor circuit breaker 20 is turned off. In FIG. 14, the current value of the circuit breaker current Is starts to decrease as the control device 100 executes step 3-3 at time T2, and the current value of the circuit breaker current Is becomes zero at time T3, that is, the semiconductor circuit is cut off. An example is shown in which the circuit breaker 20 returns to its original state (steady power transmission state) in which no circuit breaker current Is flows.

Through such a procedure, the control device 100 operates the commutation circuit 30 and the semiconductor circuit breaker 20 for a predetermined short time when the DC current interrupting device 3 is in a steady power transmission state. or a failure of the semiconductor circuit breaker 20 is detected. Also in the DC current interrupting device 3, as in the DC current interrupting device 1 of the first embodiment, the change in the current value of the detected current I52 that passes through the mechanical contact 10 and the commutation circuit 30 detected by the current detector 52 Based on the degree, it may be determined whether the commutation circuit 30 or the semiconductor circuit breaker 20 is out of order.

With such a configuration and procedure, in the DC current interrupting device 3, the control device 100 detects a failure in the commutation circuit 30 or the semiconductor circuit breaker 20. As a result, the DC current interrupting device 3 can detect a failure in the commutation circuit 30 or the semiconductor circuit breaker 20 at an early stage, and if there is a failure in the commutation circuit 30 or the semiconductor circuit breaker 20, the host controller However, the DC current interrupting device 3 and the DC power transmission system can be immediately brought to a protective stop. As a result, the DC current interrupting device 3 ensures (guarantees) that the commutation circuit 30 and the semiconductor circuit breaker 20 operate normally, and even if an accident occurs in the DC transmission line LN, the accident will not occur. The DC power transmission line LN can be normally shut off. Moreover, even in the DC current interrupting device 3, since the power transmission line current Idc flowing through the entire DC current interrupting device 3 hardly changes, the operation for detecting a failure of the commutation circuit 30 or the semiconductor circuit breaker 20 is not performed in the normal power transmission state. There will be no impact.

As explained above, according to the DC current interrupting device 3 of the third embodiment, by detecting a failure of the DC current interrupting device 3 itself at an early stage and notifying the higher-level control device, if there is a failure, Devices and systems can be immediately brought to a protective stop.

(Fourth embodiment)
The fourth embodiment will be described below. In the first to third embodiments, the control device 100 controls the commutation circuit 30 and the semiconductor based on the detected current detected by the current detector 51 or the current detector 52 attached to the internal path of the DC current interrupting device. The case where a failure of the circuit breaker 20 is detected has been described. However, for example, in the DC current interrupting device 1 of the first embodiment and the DC current interrupting device 2 of the second embodiment, the control device 100 turns on the commutation circuit 30 for a predetermined short time to detect a failure. When this state is established, the capacitor 304 included in the commutation circuit 30 discharges electric charge, so that the voltage value of the capacitor 304 changes. Utilizing this, the control device 100 can detect a failure in the commutation circuit 30 or the semiconductor circuit breaker 20 based on the degree of change over time in the voltage value of the capacitor 304 included in the commutation circuit 30. . In other words, in the DC current interrupting device 1 of the first embodiment and the DC current interrupting device 2 of the second embodiment, not only the degree of change in the current value of the detected current detected by the current detector 51 or the current detector 52 A failure of the commutation circuit 30 or the semiconductor circuit breaker 20 can also be detected based on the degree of change in the voltage value of the capacitor 304 included in the commutation circuit 30.

The DC current interrupting device in this case will be described as a DC current interrupting device 4 of a fourth embodiment. FIG. 15 is a diagram showing an example of the configuration of a commutation circuit 30 included in the DC current interrupting device 4 according to the fourth embodiment. FIG. 15 shows an example of a commutation circuit as a commutation circuit 31a, which can be installed in the DC current interrupting device 4 and has a configuration corresponding to the commutation circuit 30a shown in FIG. 3(a). In FIG. 15, components having functions common to those of the commutation circuit 30a are given the same reference numerals. The commutation circuit 31a shown in FIG. 15 includes, for example, four semiconductor switch sections 302 (semiconductor switch sections 302-1 to 302-4) and a capacitor 304, and similarly to the commutation circuit 30a, the respective configurations are This is a bidirectional H-bridge circuit configuration in which elements are connected to each other. In the commutation circuit 31a, a voltage detector 60 is attached to the capacitor 304.

Voltage detector 60 detects the voltage across attached capacitor 304 . Voltage detector 60 outputs information representing a detected value (voltage value) of the detected voltage to control device 100 . More specifically, the voltage detector 60 outputs information on the voltage value of the detected detection voltage Vc to the control device 100.

FIG. 15 shows the configuration of a commutation circuit 31a corresponding to the commutation circuit 30a shown in FIG. It can also be provided in the commutation circuit 30b shown in (b) of FIG. The configuration of the commutation circuit (eg, commutation circuit 31b) in this case may be equivalent to the configuration of the commutation circuit 31a described above.

With the configuration of such a commutation circuit (hereinafter referred to as "commutation circuit 31") that replaces the commutation circuit 30, in the DC current interrupting device 4, the control device 100 can control the DC current interrupting device 1 of the first embodiment. In the DC current interrupting device 2 of the second embodiment, instead of the detection current I51 (commutation current Ic) detected by the current detector 51 or the detection current I52 detected by the current detector 52, the voltage detector 60 A failure of the commutation circuit 31 or the semiconductor circuit breaker 20 is detected based on the degree of change over time in the voltage value of the detected detection voltage Vc. Therefore, in the DC current interrupting device 4, like the DC current interrupting device 1 of the first embodiment and the DC current interrupting device 2 of the second embodiment, the current detector 51 and the current detector 52 (current detector 53) (information representing a detected current value (current value)) may not be used.

Also in the DC current interrupting device 4, the configuration of the semiconductor circuit breaker 20 is the configuration shown in FIG. Similarly to the DC current interrupting device 1 of the first embodiment and the DC current interrupting device 2 of the second embodiment, the DC current interrupting device 4 also includes, for example, an auxiliary disconnector connected to the DC power transmission line LN. Alternatively, a configuration may be adopted in which a DC reactor for suppressing a change in current in the event of an accident is connected in the line of each DC power transmission line LN.

Hereinafter, it is assumed that the DC current interrupting device 4 has the same configuration as the DC current interrupting device 1 of the first embodiment and includes a commutation circuit 31 (commutation circuit 31a) instead of the commutation circuit 30. , its operation will be explained. The operation of the DC current interrupting device 4 to interrupt the DC power transmission line LN in which an accident has occurred is the same as that of the DC current interrupting device 1 of the first embodiment, and therefore detailed explanation will be omitted again.

[Operation to detect failure in DC current interrupting device 4]
Next, an example of an operation in which the control device 100 in the DC current interrupting device 4 detects a failure in the commutation circuit 30 (including the semiconductor circuit breaker 20) will be described. FIG. 16 is a diagram showing an example of a voltage waveform in the commutation circuit 31a included in the DC current interrupting device 4 of the fourth embodiment. The current flow and current waveform in the DC current interrupting device 4 are the same as the current flow in the DC current interrupting device 1 of the first embodiment shown in FIGS. 4 and 5, and the current flow in the first embodiment shown in FIG. The current waveform is similar to the current waveform in the DC current interrupting device 1. Therefore, in the following description, the operation of detecting a failure in the commutation circuit 31a in the DC current interrupting device 4 will be explained with reference to FIG. 16 and FIGS. 4 to 6 as appropriate.

In the DC current interrupting device 4, similarly to the DC current interrupting device 1 of the first embodiment, the control device 100 controls opening and closing of each component for a predetermined short period of time during a steady power transmission state. , ON, and OFF to detect a failure in the commutation circuit 31a. At this time, the DC current interrupting device 4 detects (determines) the failure of the commutation circuit 31a based on the degree of temporal change in the voltage value of the detected voltage Vc across the capacitor 304 detected by the voltage detector 60. do. Therefore, in the DC current interrupting device 4, the voltage is calculated based on the amount of change in the voltage value of the detected voltage Vc of the capacitor 304, which is assumed when the commutation circuit 31a is operated for a predetermined short time in order to detect a failure. A threshold value Va is predetermined. The voltage threshold value Va is determined based on, for example, the capacitance of the commutation circuit 31a and the impedance of the line parallel to the DC transmission line LN passing through the semiconductor circuit breaker 20 and the commutation circuit 30, etc. in a steady power transmission state. It is calculated and set in advance from the voltage value. Then, the control device 100 detects (determines) a failure of the commutation circuit 31a based on the voltage value of the detection voltage Vc and the voltage threshold value Va. The concept of a predetermined short time period and arbitrary timing by which the control device 100 controls each component is the same as that of the DC current interrupting device 1 of the first embodiment. Therefore, a detailed explanation of these methods will be omitted.

Since the initial state when the DC current interrupting device 4 starts the operation of detecting a failure is a steady power transmission state, the commutation circuit 31a is in an off state. For this reason, the voltage value of the detection voltage Vc of the capacitor 304 is different from the normal power transmission state in which the power transmission line current Idc is flowing through the DC power transmission line LN (see FIG. This voltage value corresponds to the amount of charge (amount of stored electricity) stored in the capacitor 304 (see ). Also in the DC current interrupting device 4, the control device 100 detects a failure in the commutation circuit 31a (including the semiconductor circuit breaker 20) by executing the following procedure at an arbitrary timing in a steady power transmission state.

(Procedure 4-1): When the control device 100 starts the operation of detecting a failure, first, the semiconductor circuit breaker 20 is turned on while the mechanical contact 10 remains closed, and then the commutation circuit 31a is turned on. turn on. As a result, the charge in the capacitor 304 included in the commutation circuit 31a is discharged, and the commutation current Ic starts to flow through the semiconductor circuit breaker 20 and the commutation circuit 31a (see FIG. 5). Along with this, the voltage across the capacitor 304 also begins to drop.

(Step 4-2): Then, the control device 100 determines whether the operation of the commutation circuit 31a or the semiconductor circuit breaker 20 is abnormal based on the voltage value of the detection voltage Vc outputted by the voltage detector 60 and the voltage threshold value Va. (Whether there is a failure or not) is determined. That is, in the DC current interrupting device 4, the control device 100 determines whether the commutation circuit 31a or the semiconductor circuit breaker 20 is out of order based on the degree of temporal change in the voltage value of the detected voltage Vc. FIG. 16 shows an example of a case where the voltage value of the detected voltage Vc starts to decrease as a result of the control device 100 executing step 4-1 at time T1. In FIG. 16, at time T2 after a predetermined short time, the degree of change in the voltage value of the detected voltage Vc from time T1 (more specifically, the difference from the voltage value of the detected voltage Vc at time T1) exceeds the voltage threshold value Va. In this case, the control device 100 determines that there is no operational abnormality in the commutation circuit 31a or the semiconductor circuit breaker 20 (no failure). On the other hand, at time T2, if the difference between the detected voltage Vc and the voltage value at time T1 is equal to or less than the voltage threshold Va, the control device 100 determines that there is an abnormality in the operation of the commutation circuit 31a or the semiconductor circuit breaker 20 ( It is determined that the device is malfunctioning. Then, the control device 100 outputs a fault signal Sf representing the determined result, and notifies the higher-level control device of the fault detection result.

The timing at which the control device 100 determines whether or not there is an abnormality in the operation of the commutation circuit 31a or the semiconductor circuit breaker 20 is not limited to the timing at time T2 when the predetermined short time described above has elapsed; The determination method may be the same as the determination method used when detecting a failure in the DC current interrupting device 1 according to the present invention. That is, the control device 100 may sample the voltage value of the detection voltage Vc at predetermined time intervals from time T1 to time T2, and determine whether the commutation circuit 31a or the semiconductor circuit breaker 20 has failed. In this case, in the DC current interrupting device 4 as well, similarly to the DC current interrupting device 1 of the first embodiment, the difference between the voltage value of the detected voltage Vc at time T1 and the voltage value of the sampled detected voltage Vc is the voltage When the threshold value Va is exceeded (that is, without waiting for time T2 to elapse), it can be determined that the commutation circuit 31a and the semiconductor circuit breaker 20 are not out of order.

(Step 4-3): After that (for example, when time T2 has elapsed, or when it is determined that the commutation circuit 31a or the semiconductor circuit breaker 20 is not out of order), the control device 100 starts the commutation circuit 31a. Then, the semiconductor circuit breaker 20 is turned off. As a result, charge is accumulated in the capacitor 304, and the voltage across the capacitor 304 begins to rise. FIG. 16 shows that the voltage value of the detection voltage Vc starts to rise as the control device 100 executes step 4-3 at time T2, and the voltage value of the detection voltage Vc returns to its original state (steady power transmission state) at time T3. ) is shown below.

Through such a procedure, the control device 100 operates the commutation circuit 31a and the semiconductor circuit breaker 20 for a predetermined short time when the DC current interrupting device 4 is in a steady power transmission state, and the commutation circuit 31a is equipped with Based on the voltage value across the capacitor 304, a failure of the commutation circuit 31a or the semiconductor circuit breaker 20 is detected.

With such a configuration and procedure, in the DC current interrupting device 4, the control device 100 detects a failure in the commutation circuit 31a or the semiconductor circuit breaker 20. As a result, the DC current interrupting device 4 can detect a failure in the commutation circuit 31a or the semiconductor circuit breaker 20 at an early stage, and if there is a failure in the commutation circuit 31a or the semiconductor circuit breaker 20, the host controller However, the DC current interrupting device 4 and the DC power transmission system can be immediately brought to a protective stop. As a result, the DC current interrupting device 4 ensures (guarantees) that the commutation circuit 31a and the semiconductor circuit breaker 20 operate normally, and even if an accident occurs in the DC transmission line LN, the accident will not occur. The DC power transmission line LN can be normally shut off.

As explained above, according to the DC current interrupting device 4 of the fourth embodiment, by detecting a failure of the DC current interrupting device 4 itself at an early stage and notifying the higher-level control device, if there is a failure, Devices and systems can be immediately brought to a protective stop. In the fourth embodiment, a configuration in which a commutation circuit 31 (commutation circuit 31a) is provided instead of the commutation circuit 30 in the DC current interrupting device 1 of the first embodiment, and a configuration in which the control device 100 is Although an example of the operation for detecting a failure has been described, the commutation circuit 30b may be provided instead of the commutation circuit 30a, or the commutation circuit 30a may be provided instead of the commutation circuit 30 in the DC current interrupting device 2 of the second embodiment. It is also possible to provide a commutation circuit 30b. The configuration of the DC current interrupting device 4 and the operation of the control device 100 in this case may be equivalent to the configuration and operation of the DC current interrupting device 4 of the fourth embodiment described above.

(Fifth embodiment)
The fifth embodiment will be described below. In the first to fourth embodiments, a case has been described in which the DC current interrupting device is configured at an intermediate position of the DC power transmission line LN. However, the DC current interrupting device can also be configured, for example, at a node portion of a plurality of DC power transmission lines LN. Even in this case, in the DC current interrupting device configured in the node portion, the commutation circuit 30 (including the commutation circuit 31) and the semiconductor interrupting A failure of the device 20 can be detected.

The DC current interrupting device in this case will be described as the DC current interrupting device 5 of the fifth embodiment. FIG. 17 is a diagram showing an example of the configuration of a DC current interrupting device according to the fifth embodiment. FIG. 17 shows a case where the DC current interrupting device 2 of the second embodiment shown in FIG. An example of a current interrupting device 5 is shown. In FIG. 17, components having functions common to those of the DC current interrupting device 2 of the second embodiment are given the same reference numerals, and any of the DC power transmission lines LN-1 to LN-3 is In order to indicate whether the component corresponds to the above, a "- (hyphen)" and a number following the hyphen are added after each symbol. In the following description, when it is not necessary to distinguish which DC power transmission line LN a component corresponds to, the hyphen attached to the reference numeral of each component and the number following the hyphen are omitted.

The DC current interrupting device 5 includes, for example, three mechanical contacts 10A (mechanical contacts 10A-1 to 10A-3), three mechanical contacts 10B (mechanical contacts 10B-1 to 10B-3), and a semiconductor The circuit breaker 20, the three commutation circuits 30 (commutation circuits 30-1 to 30-3), the three diodes 70 (diodes 70-1 to 70-3), and the three reactors 80 (reactor 80-1) 80-3), a DC bus 90, and a control device 100. FIG. 17 shows an example in which the semiconductor circuit breaker 20 has the configuration shown in FIG. 2, and each commutation circuit 30 has the configuration of the commutation circuit 30a shown in FIG. 3(a). .

In the DC current interrupting device 5, a mechanical contact 10A-1 and a mechanical contact 10B-1 are connected in series to a DC power transmission line LN-1, and a mechanical contact 10A-2 and a mechanical contact are connected to a DC power transmission line LN-2 in series. The contact 10B-2 is connected in series, and the mechanical contact 10A-3 and the mechanical contact 10B-3 are connected in series to the DC power transmission line LN-3. More specifically, in the DC power transmission line LN-1, the second pole b-A-1 of the mechanical contact 10A-1 and the first pole a-B-1 of the mechanical contact 10B-1 are connected, In the DC power transmission line LN-2, the second pole b-A-2 of the mechanical contact 10A-2 and the first pole a-B-2 of the mechanical contact 10B-2 are connected, and the DC power transmission line LN-3 , the second pole b-A-3 of the mechanical contact 10A-3 and the first pole a-B-3 of the mechanical contact 10B-3 are connected. In the DC current interrupting device 5, the first pole a-A-1 of the mechanical contact 10A-1, the first pole a-A-2 of the mechanical contact 10A-2, and the first pole a-A-2 of the mechanical contact 10A-3 are connected to each other. Each of the poles a-A-3 is connected to a DC bus 90, and is connected to the first end c of the semiconductor circuit breaker 20 via the DC bus 90. In the DC current interrupting device 5, the DC power transmission line LN-1 is located between the second pole b-A-1 of the mechanical contact 10A-1 and the first pole a-B-1 of the mechanical contact 10B-1. The first end e-1 of the commutation circuit 30-1 is connected to the first end e-1 of the commutation circuit 30-1, and the cathode of the diode 70-1 and the first end of the reactor 80-1 are connected to the second end f-1 of the commutation circuit 30-1. The second end of the reactor 80-1 is connected to the second pole bB-1 of the mechanical contact 10B-1. The same applies to the DC power transmission line LN-2 and the DC power transmission line LN-3. In the DC current interrupting device 5, the anodes of the diodes 70-1 to 70-3 belonging to the DC transmission lines LN-1 to LN-3, respectively, are connected to the second end d of the semiconductor circuit breaker 20.

In the DC current interrupting device 5, each of the mechanical contacts 10A-1 to 10A-3 is connected to each other via a DC bus 90, so that the semiconductor circuit breaker 20 is shared. Therefore, the cost and size of the DC current interrupting device 5 can be reduced compared to having three independent DC current interrupting devices 2 of the second embodiment.

In the DC current interrupting device 5, a current detector 51-1 is attached to the second end f-1 side of the commutation circuit 30-1, and a current is applied to the second pole b-A-1 side of the mechanical contact 10A-1. A detector 52-1 is attached. Current detector 51-1 and current detector 52-1 may be installed at positions different from those shown in FIG. 17 as long as they are on the same line as commutation circuit 30-1 and mechanical contact 10A-1, respectively. The same applies to the DC power transmission line LN-2 and the DC power transmission line LN-3. In the DC current interrupting device 5, for example, power transmission equipment and consumers exist on the opposite side (right side) of the DC bus 90 in each DC transmission line LN, and in normal (steady) power transmission, any DC transmission line Direct current flows from the right side of LN through the DC bus 90 to the right side of another DC power transmission line LN. That is, in the DC current interrupting device 5, current flows through at least two mechanical contacts 10A and 10B. In FIG. 17, the current detector 53 that may be installed in the DC current interrupting device 5 to detect the current flowing through each DC power transmission line LN is omitted.

When the DC current interrupting device 5 operates to interrupt the DC transmission line LN in which an accident has occurred or to detect a fault, the control device 100 controls the DC transmission line LN to be interrupted or the commutation circuit 30 (semiconductor interrupter) to detect the fault. Although the opening, closing, on, and off of each component corresponding to the device 20 (including the device 20) is controlled, the control method can be considered similar to the DC current interrupting device 2 of the second embodiment. Therefore, a detailed explanation regarding the operation of the DC current interrupting device 5 will be omitted.

As explained above, according to the DC current interrupting device 5 of the fifth embodiment, a failure of the DC current interrupting device 5 itself can be detected at an early stage and notified to the higher-level control device. As a result, if there is a failure in the commutation circuit 30 or the semiconductor circuit breaker 20 in the DC current interrupting device 5, the host control device can immediately bring the DC current interrupting device 5 or the DC power transmission system to a protective stop. . As a result, the DC current interrupting device 5 also ensures (guarantees) that the commutation circuit 30 and the semiconductor circuit breaker 20 operate normally, and even if an accident occurs in the DC transmission line LN, the accident will not occur. The DC power transmission line LN can be normally shut off.

In the fifth embodiment, a case has been described in which the DC current interrupting device 2 of the second embodiment is configured at a node portion of a plurality of DC transmission lines LN, but the DC current interrupting device 1 of the first embodiment, The DC current interrupting device 3 of the third embodiment and the DC current interrupting device 4 of the fourth embodiment can also be similarly configured at the node portions of a plurality of DC power transmission lines LN. The configuration of the DC current interrupting device 5 and the operation of the control device 100 in this case may be equivalent to the configuration and operation of the DC current interrupting device 5 of the fifth embodiment described above. In other words, the DC current interrupting device 1 of the first embodiment, the DC current interrupting device 3 of the third embodiment, and the DC current interrupting device 4 of the fourth embodiment also correspond to the respective DC power transmission lines LN. By connecting the mechanical contacts 10 of the DC current interrupting device to each other via the DC bus 90, a configuration in which the semiconductor circuit breaker 20 is shared may be configured. As a result, the DC current interrupting device 1 of the first embodiment, the DC current interrupting device 3 of the third embodiment, and the DC current interrupting device 4 of the fourth embodiment are connected to the node portions of the plurality of DC power transmission lines LN. When configured, failures can be detected early without affecting the steady power transmission state, and the cost and size are reduced compared to having multiple DC current interrupting devices for each DC transmission line LN. can do.

As described above, in the DC current interrupting device of each embodiment, the control device 100 operates at least the commutation circuit 30 (including the commutation circuit 31) for a predetermined short time. Detects failures. As a result, in the DC current interrupting device of each embodiment, it is possible to detect at least a failure in the commutation circuit 30 at an early stage, and when there is a failure in the commutation circuit 30, the host controller immediately The interrupting device 3 and the DC power transmission system can be brought to a protective stop. As a result, the DC current interrupting device of each embodiment ensures (guarantees) that at least the commutation circuit 30 operates normally, and even if an accident occurs in the DC transmission line LN, the DC current The power transmission line LN can be normally shut off. Moreover, in the DC current interrupting device of each embodiment, since the power transmission line current Idc flowing through the entire DC current interrupting device hardly changes, at least the operation of detecting a failure in the commutation circuit 30 does not affect the steady power transmission state. It will not affect you.

According to at least one embodiment described above, the mechanical contact (10) provided on the DC transmission line (LN), the semiconductor circuit breaker (20) provided in parallel to the DC transmission line, and the mechanical A commutation circuit (30) that commutates a current flowing in a path passing through a mechanical contact to a path passing through a semiconductor circuit breaker when the current is cut off, and a control device (100) that controls the mechanical contact, the semiconductor circuit breaker, and the commutation circuit. ), the control device operates the commutation circuit for a predetermined period of time (a short period of time) and then stops it at an arbitrary timing during steady state, and controls the degree of change in the current flowing through the commutation circuit within the predetermined period of time. By determining whether or not there is an abnormality in the commutation circuit based on the above, failure of the DC current interrupting device itself can be detected at an early stage, and if there is a failure, the device and system can be immediately brought to a protective stop. Can be done.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1, 2, 3, 4, 5... DC current interrupter, 10, 10A, 10A-1, 10A-2, 10A-3, 10B, 10B-1, 10B-2, 10B-3... Machine type contact, 20... semiconductor circuit breaker, 202, 202-1, 202-2... semiconductor switch section, 204... arrester, 30, 30a, 30b, 30c, 30-1, 30-2, 30 -3, 31, 31a, 31b... Commutation circuit, 302, 302-1, 302-2, 302-3, 302-4, 302-5, 302-6... Semiconductor switch section, 304...・Capacitor, 306, 306-1, 306-2...Diode, 308...Arrester, 51, 51-1, 51-2, 51-3, 52, 52-1, 52-2, 52-3 , 53... Current detector, 60... Voltage detector, 70, 70-1, 70-2, 70-3... Diode, 80, 80-1, 80-2, 80-3...・Reactor, 90... DC bus, 100... Control device, LN, LN-1, LN-2, LN-3... DC transmission line, Sf... Failure signal

Claims (12)

Mechanical contacts installed on DC power lines,
a semiconductor circuit breaker provided in parallel to the DC transmission line;
a commutation circuit that commutates a current flowing in a path passing through the mechanical contact during steady state to a path passing through the semiconductor circuit breaker when the current is interrupted;
a current detector that detects a current flowing in a path passing through the commutation circuit;
a control device that controls the mechanical contact, the semiconductor circuit breaker, and the commutation circuit;
Equipped with
The control device includes:
At an arbitrary timing during the steady state, the commutation circuit is operated for a predetermined time and then stopped;
determining whether or not there is an abnormality in the commutation circuit based on the degree of change in the current flowing through the commutation circuit within the predetermined time;
DC current interrupter. The commutation circuit is connected in series to the semiconductor circuit breaker,
A first end of the semiconductor circuit breaker on the opposite side to the commutation circuit is connected to a first pole side of the mechanical contact,
A second end of the commutation circuit opposite to the first end connected to the semiconductor circuit breaker is connected to a second pole side of the mechanical contact.
The direct current interrupting device according to claim 1. The mechanical contact includes a first mechanical contact and a second mechanical contact connected in series,
The semiconductor circuit breaker has a first end connected to a first pole side of the first mechanical contact, and a second end connected to a second pole side of the second mechanical contact,
The commutation circuit has a first end connected to a location between a second pole of the first mechanical contact and a first pole of the second mechanical contact, and a second end connected to the second pole of the second mechanical contact. connected to the second pole side of the mechanical contact;
The direct current interrupting device according to claim 1. The commutation circuit is connected in series to a second pole side of the mechanical contact in the DC power transmission line,
The semiconductor circuit breaker has a first end connected to the first pole side of the mechanical contact, and a second end connected to the mechanical contact in the commutation circuit. connected to the end,
The direct current interrupting device according to claim 1. The control device includes :
determining whether or not there is an abnormality in the commutation circuit based on the degree of change in the detected value of the current detector after operating the commutation circuit for the predetermined time;
The direct current interrupting device according to any one of claims 1 to 4. further comprising a current detector that detects a current flowing in a path passing through the semiconductor circuit breaker,
The control device includes:
determining whether or not there is an abnormality in the commutation circuit based on the degree of change in the detected value of the current detector after operating the commutation circuit for the predetermined time;
The direct current interrupting device according to any one of claims 1 to 5. further comprising a current detector that detects a current flowing in a path passing through the mechanical contact,
The control device includes:
determining whether or not there is an abnormality in the commutation circuit based on the degree of change in the detected value of the current detector after operating the commutation circuit for the predetermined time;
The direct current interrupting device according to any one of claims 1 to 6. The commutation circuit includes an energy storage element that stores energy, and a voltage detector that detects a voltage according to the energy stored in the energy storage element,
The control device includes:
determining whether or not there is an abnormality in the commutation circuit based on the degree of change in the detection value of the voltage detector after operating the commutation circuit for the predetermined time;
The direct current interrupting device according to any one of claims 1 to 7. The control device includes:
determining that there is an abnormality in the commutation circuit when the degree of change over time of the detected value is less than or equal to a preset threshold;
The direct current interrupting device according to any one of claims 5 to 8. The arbitrary timing during the steady state is such that the current value of the current flowing through the DC transmission line is less than the rated value, and the amount of change in the current flowing through the commutation circuit when the commutation circuit is operated for the predetermined time. When it is lower than
The direct current interrupting device according to any one of claims 1 to 9. The arbitrary timing during the steady state is when the current value of the current flowing through the DC power transmission line is higher than the amount of change in the current flowing through the commutation circuit when the commutation circuit is operated for the predetermined time. ,
The direct current interrupting device according to any one of claims 1 to 10. When the control device determines that there is an abnormality in the commutation circuit, it notifies a higher-level control device that instructs the operation of the DC current interrupting device that there is an abnormality in the commutation circuit.
The direct current interrupting device according to any one of claims 1 to 11.

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