WO2021140534A1

WO2021140534A1 - Dc circuit breaker

Info

Publication number: WO2021140534A1
Application number: PCT/JP2020/000019
Authority: WO
Inventors: 裕史児山; 崇裕石黒
Original assignee: 東芝エネルギーシステムズ株式会社
Priority date: 2020-01-06
Filing date: 2020-01-06
Publication date: 2021-07-15
Also published as: JP7318010B2; JPWO2021140534A1

Abstract

Provided is a DC breaking device having a plurality of first mechanical contact points, a plurality of second mechanical contact points, a plurality of commutation circuits, a first semiconductor circuit breaker, and a second semiconductor circuit breaker. The first mechanical contact points are respectively provided in a plurality of DC power transmission lines constituting a DC system. The second mechanical contact points are respectively provided between the plurality of first mechanical contact points and a common power transmission line to which the plurality of DC power transmission lines are commonly connected. The plurality of commutation circuits each have a capacitor and commutate the current flowing in a first direction toward the common power transmission line from any one of the plurality of DC power transmission lines or the current flowing in a second direction toward the DC power transmission lines from the common power transmission line. The first semiconductor circuit breaker can interrupt the current commutated by the commutation circuits and flowing in the first direction. The second semiconductor circuit breaker has a second end connected to the common power transmission line and can interrupt the current commutated by the commutation circuits and flowing in the second direction.

Description

DC circuit breaker

An embodiment of the present invention relates to a DC circuit breaker.

In recent years, electric power has been transmitted by a DC transmission network composed of multiple DC transmission lines. In the case of an accident in the DC power grid, only a specific power line may be cut off and the remaining power lines may continue to transmit power. In this regard, there is known a technique relating to a DC current cutoff device that is used at a coupling point of a plurality of DC power transmission lines and cuts off a current flowing through a part or all of the plurality of DC power transmission lines.

However, with the conventional DC current cutoff device, even if the current flowing from each DC transmission line to the coupling point can be cut off, it may be difficult to cut off the current flowing from the coupling point to each DC transmission line.

International Publication No. 2019/035180

An object to be solved by the present invention is to provide a DC current cutoff device capable of cutting off bidirectional current at a coupling point of a plurality of DC power transmission lines.

The DC current breaker of the embodiment has a plurality of first mechanical contacts, a plurality of second mechanical contacts, a plurality of commutation circuits, a first semiconductor breaker, and a second semiconductor breaker. The first mechanical contact is provided on each of a plurality of DC transmission lines constituting the DC system. The second mechanical contact is provided between the plurality of first mechanical contacts and a common power transmission line commonly connected to the plurality of DC power transmission lines. In the plurality of commutation circuits, each commutation circuit has a capacitor, and the current flowing in the first direction from any one of the plurality of DC transmission lines to the common transmission line, or the common It commutates the current flowing in the second direction from the transmission line to the DC transmission line. In the first semiconductor circuit breaker, the first end is connected to the common power transmission line, the second end is connected to the plurality of DC power transmission lines, and the current flowing in the first direction to which the commutation circuit is commuted is cut off. It is possible. In the second semiconductor circuit breaker, the first end is connected to each of the plurality of DC power transmission lines, the second end is connected to the common power transmission line, and the current flowing in the second direction to which the commutation circuit is commuted is transmitted. It can be blocked.

It is a figure which shows an example of the structure of the direct current cutoff device 1 of 1st Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the 1st DC power transmission line LN1 in which a DC system current flows in a 2nd direction is cut off individually in 1st Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene which charges a capacitor C in 1st Embodiment. It is a figure which shows an example of the state of the DC current circuit breaker 1 in the scene where the DC system current which concerns on 1st Embodiment is commutated to the semiconductor circuit breaker 40. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the common power transmission line LNc and the first DC power transmission line LN1 are electrically cut off in the 1st Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the 3rd DC power transmission line LN3 in which the DC system current flows in the 1st direction is cut off individually in 1st Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene which charges a capacitor C in 1st Embodiment. It is a figure which shows an example of the state of the DC current circuit breaker 1 in the scene where the DC system current which concerns on 1st Embodiment is commutated to the semiconductor circuit breaker 40. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the common power transmission line LNc and the third DC power transmission line LN3 are electrically cut off in the 1st Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where an accident occurs in a common power transmission line LNc. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the DC transmission line LN through which the DC system current flows in the 1st direction is completely cut off in the 1st Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene which charges a capacitor C in 1st Embodiment. It is a figure which shows an example of the state of the DC current circuit breaker 1 in the scene where the DC system current which concerns on 1st Embodiment is commutated to the semiconductor circuit breaker 40. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the common power transmission line LNc and the DC power transmission line LN are electrically cut off. It is a flowchart which shows an example of the process of a direct current cutoff device 1. It is a figure which shows an example of the structure of the direct current cutoff device 1a of 2nd Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene which charges a capacitor C in 2nd Embodiment. It is a figure which shows an example of the state of the DC current circuit breaker 1a in the scene where the DC system current which concerns on 2nd Embodiment is transferred to the semiconductor circuit breaker 40. It is a figure which shows an example of the state of the DC current cutoff device 1 in the scene where the common power transmission line LNc and the first DC power transmission line LN1 are electrically cut off in the 2nd Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene where the 3rd DC power transmission line LN3 in which the DC system current flows in the 1st direction is cut off individually in 2nd Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene which charges a capacitor C in 2nd Embodiment. It is a figure which shows an example of the state of the DC current circuit breaker 1a in the scene where the DC system current which concerns on 2nd Embodiment is transferred to the semiconductor circuit breaker 40. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene where the common power transmission line LNc and the third DC power transmission line LN3 are electrically cut off in the 2nd Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene where the common power transmission line LNc has an abnormality. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene which cuts off the DC transmission line LN through which the DC system current flows in the 1st direction in the 2nd Embodiment. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene which charges a capacitor C in 2nd Embodiment. It is a figure which shows an example of the state of the DC current circuit breaker 1a in the scene where the DC system current which concerns on 2nd Embodiment is transferred to the semiconductor circuit breaker 40. It is a figure which shows an example of the state of the DC current cutoff device 1a in the scene where the common power transmission line LNc and the DC power transmission line LN are electrically cut off. It is a figure which shows another example of the position of the reactor 80 in the DC current cutoff device 1. It is a figure which shows another example of the position of the reactor in the DC current cutoff device 1a.

Hereinafter, the DC circuit breaker of the embodiment will be described with reference to the drawings.

(First Embodiment)
[Configuration of DC current cutoff device 1]
FIG. 1 is a diagram showing an example of the configuration of the DC current cutoff device 1 of the first embodiment. The DC current cutoff device 1 is, for example, a device that electrically conducts or cuts off a plurality of DC power transmission lines constituting a DC system and a common power transmission line LNc connecting these DC power transmission lines. Hereinafter, the DC current cutoff device 1 electrically conducts the three DC transmission lines of the first DC transmission line LN1, the second DC transmission line LN2, and the third DC transmission line LN3 with the common transmission line LNc, respectively. , Or a device that shuts off.

Hereinafter, the configuration related to the first DC power transmission line LN1 is given a "-1" at the end of the code, and the configuration related to the second DC power transmission line LN2 is given a "-2" at the end of the code. The configuration related to the third DC power transmission line LN3 will be described by adding "-3" to the end of the reference numerals. When it is not distinguished which DC transmission line configuration is used, the description will be given without adding numbers below the hyphen. When the first DC transmission line LN1, the second DC transmission line LN2, and the third DC transmission line LN3 are not distinguished, they are described as DC transmission line LN.

The DC current circuit breaker 1 includes a plurality of first mechanical contacts 10, a plurality of second mechanical contacts 20, a plurality of commutation circuits 30, a first semiconductor circuit breaker 40-R, and a second semiconductor circuit breaker. It includes 40-L, a plurality of arresters 50, a plurality of first diodes 60, a plurality of second diodes 70, a plurality of reactors 80, and a control unit 100. The numbers of the first mechanical contact 10, the second mechanical contact 20, the commutation circuit 30, the first diode 60, the second diode 70, and the reactor 80 included in the DC current cutoff device 1 are different. The number corresponds to the number of DC transmission line LNs (three in this case) connected to the DC current cutoff device 1. Further, the number of arresters 50 included in the DC current breaker 1 is a number corresponding to the number of semiconductor breakers (in this case, two) included in the DC current breaker 1.

Hereinafter, when the first semiconductor circuit breaker 40-R and the second semiconductor circuit breaker 40-L are not distinguished, they are described as the semiconductor circuit breaker 40. Further, it is assumed that the DC current cutoff device 1 includes two arresters, an arrester 50-R and an arrester 50-L. When the arrester 50-R and the arrester 50-L are not distinguished, it is described as the arrester 50.

As shown in FIG. 1, the first mechanical contact 10-1 is provided on the first DC transmission line LN1, the first mechanical contact 10-2 is provided on the second DC transmission line LN2, and the first mechanical contact is provided. The contacts 10-3 are provided on the third DC transmission line LN3. Further, the second mechanical contact 20-1 is provided between the common transmission line LNc and the first mechanical contact 10-1, and the second mechanical contact 20-2 is the common transmission line LNc and the first machine. The second mechanical contact 20-3 is provided between the common transmission line LNc and the first mechanical contact 10-3.

An auxiliary disconnector MS may be further provided between each DC transmission line LN and the first mechanical contact 10. Hereinafter, it is assumed that an auxiliary disconnector MS is provided between each DC transmission line LN and the first mechanical contact 10. Specifically, an auxiliary disconnector MS-1 is provided between the first DC transmission line LN1 and the first mechanical contact 10-1, and the second DC transmission line LN2 and the first mechanical contact 10- An auxiliary disconnector MS-2 is provided between the two, and an auxiliary disconnector MS-3 is provided between the third DC transmission line LN3 and the first mechanical contact 10-3.

The first mechanical contact 10 includes a first terminal 10a and a second terminal 10b, the second mechanical contact 20 includes a first terminal 20a and a second terminal 20b, and the auxiliary disconnector MS includes an auxiliary disconnector MS. It includes a first terminal MSa and a second terminal MSb. The second terminal MSb of the auxiliary disconnector MS-1 is connected to the first DC transmission line LN1. The first terminal MSa of the auxiliary disconnector MS-1 and the second terminal 10b of the first mechanical contact 10-1 are connected to each other. The first terminal 10a of the first mechanical contact 10-1 and the second terminal 20b of the second mechanical contact 20-1 are connected to each other. The first terminal 20a of the second mechanical contact 20-1 is connected to the common power transmission line LNc. The second terminal MSb of the auxiliary disconnector MS-2 is connected to the second DC transmission line LN2. The first terminal MSa of the auxiliary disconnector MS-2 and the second terminal 10b of the first mechanical contact 10-2 are connected to each other. The first terminal 10a of the first mechanical contact 10-2 and the second terminal 20b of the second mechanical contact 20-2 are connected to each other. The first terminal 20a of the second mechanical contact 20-2 is connected to the common power transmission line LNc. The second terminal MSb of the auxiliary disconnector MS-3 is connected to the third DC transmission line LN3. The first terminal MSa of the auxiliary disconnector MS-3 and the second terminal 10b of the first mechanical contact 10-3 are connected to each other. The first terminal 10a of the first mechanical contact 10-3 and the second terminal 20b of the second mechanical contact 20-3 are connected to each other. The first terminal 20a of the second mechanical contact 20-3 is connected to the common power transmission line LNc.

The semiconductor circuit breaker 40 includes, for example, a plurality of (four in the figure) switching units connected in series with each other. Each of the switching units includes a switching element and a diode connected in parallel with each other. Specifically, the cathode of the diode and the collector of the switching element are connected to each other, and the anode of the diode and the emitter of the switching element are connected to each other. The switching element is, for example, a semiconductor switching element such as an insulated gate bipolar transistor (hereinafter, IGBT: Insulated Gate Bipolar Transistor). However, the switching element is not limited to the IGBT. The switching element may be any element as long as it can realize self-extinguishing. In the following description, a case where the switching element is an IGBT will be described. Further, in the following description, the emitter of the switching element of the switching unit is also referred to as "emitter of the switching unit", and the collector of the switching element of the switching unit is also described as "collector of the switching unit".

In the semiconductor circuit breaker 40, the emitter of the switching unit and the collector of the switching unit adjacent to the switching unit are connected. The semiconductor circuit breaker 40 includes a first terminal 40a and a second terminal 40b. Of the plurality of switching portions included in the semiconductor circuit breaker 40, the collector of the switching portion at the end and the cathode of the diode connected in parallel to the switching portion at the end are connected to the first terminal 40a. The second terminal 40b has an emitter of a switching portion at another end and an anode of a diode connected in parallel to the switching portion at the other end among a plurality of switching portions included in the semiconductor circuit breaker 40. Be connected.

In the following description, the fact that the switching element included in the semiconductor circuit breaker 40 is in the ON state is also described as “the semiconductor circuit breaker 40 is in the closed state”, and the switching element included in the semiconductor circuit breaker 40 is in the OFF state. Is also described as "the semiconductor circuit breaker 40 is in the open state".

The second terminal 40b of the first semiconductor circuit breaker 40-R is connected to the common power transmission line LNc. Further, the first terminal 40a of the first semiconductor circuit breaker 40-R is connected to the DC power transmission line LN via the second diode 70. Specifically, the first terminal 40a is connected to the cathodes of the second diodes 70-1 to 70-3. The anode of the second diode 70-1 and the other end of the reactor 80-1, the second terminal 10b of the first mechanical contact 10-1, and the first terminal MSa of the auxiliary disconnector MS-1 are connected to each other. Be connected. The anode of the second diode 70-2, the other end of the reactor 80-2, the second terminal 10b of the first mechanical contact 10-2, and the first terminal MSa of the auxiliary disconnector MS-2 are connected to each other. Be connected. The anode of the second diode 70-3, the other end of the reactor 80-3, the second terminal 10b of the first mechanical contact 10-3, and the first terminal MSa of the auxiliary disconnector MS-3 are connected to each other. Be connected.

Due to the connection relationship described above, the second diodes 70-1 to 70-3 allow the current flowing from the DC transmission line LN to the first direction of the common transmission line LNc, and allow the current flowing from the common transmission line LNc to the second DC transmission line LN. Block the current flowing in the direction. Hereinafter, the direction from the DC transmission line LN to the common transmission line LNc is also described as "first direction" or "inward", and the direction from the common transmission line LNc to the DC transmission line LN is "second direction" or "outside". Also described as "direction".

The first terminal 40a of the second semiconductor circuit breaker 40-L is connected to the common power transmission line LNc. Further, the second terminal 40b of the second semiconductor circuit breaker 40-L is connected to the DC power transmission line LN via the first diode 60 and the reactor 80. Specifically, the second terminal 40b is connected to the anodes of the first diodes 60-1 to 60-3. The cathode of the first diode 60-1 and the second terminal 30b of the commutation circuit 30-1 and one end of the reactor 80-1 are connected to each other, and the other end of the reactor 80-1 and the first mechanical type are connected to each other. The second terminal 10b of the contact 10-1 and the first terminal MSa of the auxiliary disconnector MS-1 are connected to each other. The cathode of the first diode 60-2, the second terminal 30b of the commutation circuit 30-2, and one end of the reactor 80-2 are connected to each other, and the other end of the reactor 80-2 and the first mechanical type. The second terminal 10b of the contact 10-2 and the first terminal MSa of the auxiliary disconnector MS-2 are connected to each other. The cathode of the first diode 60-3, the second terminal 30b of the commutation circuit 30-3, and one end of the reactor 80-3 are connected to each other, and the other end of the disconnector 80-3 and the first mechanical type. The second terminal 10b of the contact 10-3 and the first terminal MSa of the auxiliary disconnector MS-3 are connected to each other.

Due to the connection relationship described above, the first diodes 60-1 to 60-3 allow the current flowing from the common transmission line LNc to the DC transmission line LN, and the current flowing from the DC transmission line LN to the common transmission line LNc. To prevent.

The arrester 50-R is connected in parallel with the first semiconductor circuit breaker 40-R between the common power transmission line LNc and the second diode 70. Further, the arrester 50-L is connected in parallel with the second semiconductor circuit breaker 40-L between the common power transmission line LNc and the first diode 60. The arrester 50 absorbs surge energy generated by controlling the semiconductor circuit breaker 40 to be in the open state.

Due to the connection relationship described above, the first semiconductor circuit breaker 40-R is used to extinguish the DC system current in the first direction flowing from the DC transmission line LN to the common transmission line LNc to the arrester 50-R. The semiconductor circuit breaker 40-L is used to extinguish the DC system current in the second direction flowing from the common transmission line LNc to the DC transmission line LN to the arrester 50-L.

The commutation circuit 30 includes, for example, a plurality of switching units (switching units 310a to 310d in the figure) and a capacitor C. Each of the switching units includes a switching element and a diode connected in parallel with each other. The switching unit 310c and the switching unit 310a are connected in series between the positive electrode and the negative electrode of the commutation circuit 30 in the order described, and the switching unit 310b and the switching unit 310d are rotated in the order described. It is connected in series between the positive electrode and the negative electrode of the flow circuit 30. The emitter of the switching unit 310c and the collector of the switching unit 310a are connected to each other. The emitter of the switching unit 310b and the collector of the switching unit 310d are connected to each other. The collector of the switching unit 310c, the collector of the switching unit 310b, and the positive electrode of the capacitor C are connected to each other. The emitter of the switching unit 310a, the emitter of the switching unit 310d, and the negative electrode of the capacitor C are connected to each other.

The first terminal 30a of the commutation circuit 30 is provided at the connection point between the collector of the switching unit 310a and the emitter of the switching unit 310c. A second terminal 30b of the commutation circuit 30 is provided at a connection point between the emitter of the switching unit 310b and the collector of the switching unit 310d.

The first terminal 30a of the commutation circuit 30-1, the second terminal 20b of the second mechanical contact 20-1, and the first terminal 10a of the first mechanical contact 10-1 are connected to each other. The first terminal 30a of the commutation circuit 30-2, the second terminal 20b of the second mechanical contact 20-2, and the first terminal 10a of the first mechanical contact 10-2 are connected to each other. The first terminal 30a of the commutation circuit 30-3, the second terminal 20b of the second mechanical contact 20-3, and the first terminal 10a of the first mechanical contact 10-3 are connected to each other.

The second terminal 30b of the commutation circuit 30-1 and the cathode of the first diode 60-1 are connected to each other, and the second terminal 30b of the commutation circuit 30-2 and the cathode of the first diode 60-2 are connected to each other. They are connected to each other, and the second terminal 30b of the commutation circuit 30-3 and the cathode of the first diode 60-3 are connected to each other. As a result, the reactor 80 is provided between the second terminal 30b and the second terminal 20b.

The control unit 100 controls the opening / closing of the auxiliary disconnector MS, the first mechanical contact 10, the second mechanical contact 20, the semiconductor circuit breaker 40, and the operation of the commutation circuit 30 (that is, the opening / closing of the switching units 310a to 310d). Control) etc.

As shown in FIG. 1, in a state where the common power transmission line LNc and the DC power transmission line LN are electrically conducted by the DC current cutoff device 1 (hereinafter, normal conduction state), each part is in the following state. It has become.
・ Auxiliary disconnector MS: closed state ・ 1st mechanical contact 10: closed state ・ 2nd mechanical contact 20: closed state ・ commutation circuit 30: off state ・ Capacitor C provided in commutation circuit 30: charged state -Semiconductor breaker 40: Open state

In the normal conduction state shown in FIG. 1, a DC system current in the second direction is flowing through the first DC transmission line LN1 and the second DC transmission line LN2. Further, a DC system current in the first direction flows through the third DC transmission line LN3.

The DC current cutoff device 1 performs various cutoff controls according to the direction of the DC system current flowing through the DC power transmission line LN to be cut off, and cuts off the common power transmission line LNc and the DC power transmission line LN. Hereinafter, the details of the control of the DC current cutoff device 1 will be described.

[Individual cutoff in the second direction]
FIG. 2 is a diagram showing an example of a state of the DC current cutoff device 1 in a scene where the first DC power transmission line LN1 in which the DC system current flows in the second direction is individually cut off in the first embodiment. In the scene shown in FIG. 2, an abnormality has occurred in the first DC power transmission line LN1. The abnormality that occurs in the DC transmission line LN is, for example, an abnormality that occurs due to an accident such as a ground fault or a short circuit. The control unit 100 receives a cutoff instruction signal from the control system (not shown). The control system is, for example, a system that controls the supply (accommodation) of electric power between each power system, and when an abnormality occurs in the DC system, a cutoff instruction signal is sent to the target DC current cutoff device 1 (control unit 100). To send. The cutoff instruction signal is, for example, a signal instructing a DC power transmission line LN that electrically cuts off the common power transmission line LNc. When the control unit 100 receives a cutoff instruction signal from the control system, the control unit 100 controls the first mechanical contact 10 and the second mechanical contact 20 provided on the target DC transmission line LN in an open state, and controls the target DC in an open state. Of the plurality of switching units 310 included in the commutation circuit 30 related to the transmission line LN, the switching unit 310 according to the direction of the DC system current flowing through the target DC transmission line LN is controlled to be in the ON state.

In the scene shown in FIG. 2, it is shown that the cutoff instruction signal electrically cuts off the first DC power transmission line LN1 and the common power transmission line LNc. When the DC system current flowing through the DC transmission line LN to be cut off (in this case, the first DC transmission line LN1) is in the second direction, the control unit 100 includes the following parts of the DC current cutoff device 1. Control to state. The operation of the commutation circuit 30 when the DC system current is in the first direction will be described later.
Auxiliary disconnector MS-1: Closed state-First mechanical contact 10-1: Open state-Second mechanical contact 20-1: Open state-Switching

units

310a and 310b of commutation circuit 30-1: ON state -Switching

units

310c, 310d of the commutation circuit 30-1: Off state-Semiconductor disconnector 40: Open state (The configuration related to the second DC transmission line LN2 and the configuration related to the third DC transmission line LN3 are described above. Normally remains in a conductive state.)

By the control of the control unit 100 described above, the first mechanical contact 10-1 and the second mechanical contact 20-1 of the DC current cutoff device 1 are mechanically controlled to be in an open state, but the contacts are simply separated. However, since an arc is generated between the contacts, it cannot be electrically cut off. In this state, when the control unit 100 operates the commutation circuit 30-1, the switching

units

310a and 310b included in the commutation circuit 30-1 are controlled to be on. Then, the commutation circuit 30-1 discharges the electric charge stored in the capacitor C from the positive electrode of the capacitor C via the switching unit 310b, the reactor 80-1, the first mechanical contact 10-1, and the switching unit 310a. A circuit is formed in which the current returns through the path rt1 to the negative electrode of the capacitor C. This circuit is formed by connecting the first diode 60-1 to the reactor 80-1 in the direction described above, so that the common power transmission line LNc is formed via the second semiconductor circuit breaker 40-L. This is to block the current flowing in the direction, and the diode of the first semiconductor circuit breaker 40-R blocks the current flowing in the direction of the common power transmission line LNc. Since the current flowing back through this circuit is the current flowing in the second direction from the common transmission line LNc to the first DC transmission line LN1 in the first mechanical contact 10-1, the first mechanical contact 10 It acts to cancel the arc generated at -1. As a result, the current flowing through the first mechanical contact 10-1 becomes zero, and the first mechanical contact 10-1 is in an electrically cut-off state.

FIG. 3 is a diagram showing an example of a state of the DC current cutoff device 1 in the scene where the capacitor C is charged in the first embodiment. The control unit 100 charges the capacitor C of the commutation circuit 30-1 in preparation for the next reclosing circuit when the first mechanical contact 10-1 is mechanically and electrically cut off. At the same time, in order to transfer the DC system current to the second semiconductor circuit breaker 40-L that cuts off the DC system current in the second direction, each part included in the DC current cutoff device 1 is controlled to the following state.
Auxiliary disconnector MS-1: Closed state-First mechanical contact 10-1: Open state-Second mechanical contact 20-1: Open state-Switching

parts

310a and 310b of commutation circuit 30-1: Off state -Switching

units

310c, 310d of the commutation circuit 30-1: Off state-First semiconductor circuit breaker 40-R: Open state-Second semiconductor circuit breaker 40-L: Closed state (configuration related to the second DC transmission line LN2) And the configuration related to the third DC transmission line LN3 remains in the normal conduction state described above.)

Under the control of the control unit 100 described above, the DC system current flowing from the common transmission line LNc to the first DC transmission line LN1 is the second mechanical contact 20-1, the switching unit 310c, the capacitor C, the switching unit 310d, and the reactor 80. It flows via the route rt2 via -1. As a result, the DC current cutoff device 1 can charge the capacitor C included in the commutation circuit 30-1 and sufficiently output the current flowing back through the path rt1 after the next reclosing.

Further, as the second semiconductor circuit breaker 40-L is controlled to the closed state, the DC system current flowing from the common transmission line LNc to the DC transmission line LN is transferred to the switching element of the second semiconductor circuit breaker 40-L and the DC transmission line LN. It joins the path rt2 via the path rt3 via the first diode 60-1. As a result, the DC current cutoff device 1 gradually transfers the DC system current flowing from the common transmission line LNc to the path via the second mechanical contact 20-1, the commutation circuit 30, and the auxiliary disconnector MS-1. It can be commutated to the second semiconductor circuit breaker 40-L.

FIG. 4 is a diagram showing an example of a state of the DC current circuit breaker 1 in a scene where the DC system current according to the first embodiment is transferred to the semiconductor circuit breaker 40. In the scene of FIG. 4, the DC system current does not flow through the commutation circuit 30-1, but flows through the second mechanical contact 20-1 and the commutation circuit 30-1 to the first DC transmission line LN1. The DC system current is transferred to the path rt4 via the second semiconductor circuit breaker 40-L and the first diode 60-1. Along with this, the arc of the second mechanical contact 20-1 is extinguished by the zero point of the current, and the second mechanical contact 20-1 is mechanically and electrically controlled to be in an open state.

After the DC system current in the second direction flowing from the common power transmission line LNc to the first DC power transmission line LN1 is transferred to the second semiconductor circuit breaker 40-L, the control unit 100 sets each part of the DC current cutoff device 1. Control to the following states.
Auxiliary disconnector MS-1: Closed state-First mechanical contact 10-1: Open state-Second mechanical contact 20-1: Open state-Commuting circuit 30-1: Off state-First semiconductor circuit breaker 40-R: Open state / Second semiconductor circuit breaker 40-L: Closed state → Open state (The configuration related to the second DC transmission line LN2 and the configuration related to the third DC transmission line LN3 are the above-mentioned normal conduction states. as it is.)

The surge energy generated when the second semiconductor circuit breaker 40-L is controlled to the open state is absorbed by the arrester 50-L. As a result, the DC current cutoff device 1 can electrically cut off the common power transmission line LNc and the first DC power transmission line LN1. Then, the control unit 100 finally opens the auxiliary disconnector MS-1 after the current flowing through the arrester 50-L becomes zero. When the auxiliary disconnector MS-1 is controlled to the open state, no current is already flowing, so no arc is generated.

The control unit 100 determines the timing at which the DC system current is transferred to the second semiconductor circuit breaker 40-L, such as the capacitor voltage of the capacitor C of the commutation circuit 30-1 and the first mechanical contact 10-1. It may be determined (determined) based on the current, or it may be determined (determined) based on the elapse of a predetermined time after the cutoff operation of the first DC transmission line LN1 is started.

FIG. 5 is a diagram showing an example of the state of the DC current cutoff device 1 in the scene where the common power transmission line LNc and the first DC power transmission line LN1 are electrically cut off in the first embodiment. As shown in FIG. 5, since the first mechanical contact 10-1, the second mechanical contact 20-1, and the auxiliary disconnector MS-1 are controlled in the open state, the common transmission line LNc and the first DC transmission line It is electrically cut off from LN1. As a result, the DC current cutoff device 1 suppresses the influence of the second DC transmission line LN2 and the third DC transmission line LN3 by the abnormality occurring in the first DC transmission line LN1, and suppresses the influence on the first DC transmission line LN1 other than the first DC transmission line LN1. It is possible to continue the supply of power by the DC system by the DC transmission line LN of.

[Individual cutoff in the first direction]
FIG. 6 is a diagram showing an example of a state of the DC current cutoff device 1 in a scene where the third DC transmission line LN3 through which the DC system current flows in the first direction is individually cut off in the first embodiment. In the scene shown in FIG. 6, an abnormality has occurred in the first DC power transmission line LN1. The control unit 100 receives a cutoff instruction signal from the control system.

In the scene shown in FIG. 6, it is shown that the cutoff instruction signal electrically cuts off the third DC power transmission line LN3 and the common power transmission line LNc. When the DC system current flowing through the DC transmission line LN to be cut off (in this example, the third DC transmission line LN3) is in the first direction, the control unit 100 describes each part included in the DC current cutoff device 1 as follows. Control to the state.
-Auxiliary disconnector MS-3: Closed state-First mechanical contact 10-3: Open state-Second mechanical contact 20-3: Open state-Switching

parts

310a and 310b of commutation circuit 30-3: Off state The switching

units

310c and 310d of the commutation circuit 30-3: on state and the semiconductor circuit breaker 40: open state (the configuration related to the first DC transmission line LN1 and the configuration related to the second DC transmission line LN2 are described above. Normally remains in a conductive state.)

By the control of the control unit 100 described above, the first mechanical contact 10-3 and the second mechanical contact 20-3 of the DC current cutoff device 1 are mechanically controlled to be in an open state, but the contacts are simply separated. However, since an arc is generated between the contacts, it cannot be electrically cut off. In this state, when the control unit 100 operates the commutation circuit 30-3, the switching

units

310c and 310d included in the commutation circuit 30-3 are controlled to be on. Then, the commutation circuit 30-3 discharges the electric charge stored in the capacitor C from the positive electrode of the capacitor C via the switching unit 310c, the first mechanical contact 10-3, the reactor 80-3, and the switching unit 310d. A circuit is formed in which a current returns through the path rt5 to the negative electrode of the capacitor C. Since the current flowing back through this circuit is the current flowing in the first direction of the common power transmission line LNc from the third DC power transmission line LN3 at the first mechanical contact 10-3, the current flows in the direction opposite to the current flowing in the first direction of the common power transmission line LNc. It acts to cancel the arc generated at -3. As a result, the current flowing through the first mechanical contact 10-3 becomes zero, and the first mechanical contact 10-3 is in an electrically cutoff state.

FIG. 7 is a diagram showing an example of a state of the DC current cutoff device 1 in the scene where the capacitor C is charged in the first embodiment. The control unit 100 charges the capacitor C of the commutation circuit 30-3 in preparation for the next reclosing circuit when the first mechanical contact 10-3 is mechanically and electrically cut off. At the same time, in order to transfer the DC system current to the first semiconductor circuit breaker 40-R that cuts off the DC system current in the first direction, each part included in the DC current cutoff device 1 is controlled to the following state.
-Auxiliary disconnector MS-3: Closed state-First mechanical contact 10-3: Open state-Second mechanical contact 20-3: Open state-Switching

parts

310a and 310b of commutation circuit 30-3: Off state -Switching

units

310c and 310d of the commutation circuit 30-3: Off state-First semiconductor circuit breaker 40-R: Closed state-Second semiconductor circuit breaker 40-L: Open state (configuration related to the first DC transmission line LN1) And the configuration related to the second DC transmission line LN2 remains in the normal conduction state described above.)

Under the control of the control unit 100 described above, the DC system current flowing from the third DC transmission line LN3 to the common transmission line LNc is the auxiliary disconnector MS-3, the reactor 80-3, the switching unit 310b, the capacitor C, the switching unit 310a, And flows via the path rt6 via the second mechanical contact 20-3. As a result, the DC current cutoff device 1 can charge the capacitor C included in the commutation circuit 30-3 and sufficiently output the current flowing back through the path rt5 after the next reclosing.

Further, as the first semiconductor circuit breaker 40-R is controlled to the closed state, the DC system current flowing from the third DC transmission line LN3 to the common transmission line LNc is the second diode 70-3 and the first semiconductor. It flows through the path rt7 via the switching element of the circuit breaker 40-R. As a result, the DC current cutoff device 1 transfers the DC system current flowing from the third DC transmission line LN3 to the path via the auxiliary disconnector MS-3, the commutation circuit 30-3, and the second mechanical contact 20-3. It can be gradually commutated to the first semiconductor circuit breaker 40-R.

FIG. 8 is a diagram showing an example of a state of the DC current circuit breaker 1 in a scene where the DC system current according to the first embodiment is transferred to the semiconductor circuit breaker 40. In the scene of FIG. 8, the direct current system current stopped flowing in the commutation circuit 30-3, and the direct current flowing in the common transmission line LNc via the commutation circuit 30-3 and the second mechanical contact 20-3. The system current is transferred to the path rt7 via the second diode 70-3 and the first semiconductor circuit breaker 40-R. Along with this, the arc of the second mechanical contact 20-3 is extinguished by the zero point of the current, and the second mechanical contact 20-3 is mechanically and electrically controlled to be in an open state.

The control unit 100 transfers each part of the DC current circuit breaker 1 after the DC system current in the first direction flowing from the third DC power transmission line LN3 to the common power transmission line LNc is transferred to the first semiconductor circuit breaker 40-R. Control to the following states.
-Auxiliary disconnector MS-3: Closed state-First mechanical contact 10-3: Open state-Second mechanical contact 20-3: Open state-Commuting circuit 30-3: Off state-First semiconductor circuit breaker 40-R: Closed state → Open state ・ Second semiconductor circuit breaker 40-L: Open state (The configuration related to the first DC transmission line LN1 and the configuration related to the second DC transmission line LN2 are in the above-mentioned normal conduction state. as it is.)

The surge energy generated when the first semiconductor circuit breaker 40-R is controlled to the open state is absorbed by the arrester 50-R. As a result, the DC current cutoff device 1 can electrically cut off the common power transmission line LNc and the third DC power transmission line LN3. Then, the control unit 100 finally opens the auxiliary disconnector MS-3 after the current flowing through the arrester 50-R becomes zero. When the auxiliary disconnector MS-3 is controlled to the open state, no current is already flowing, so no arc is generated.

FIG. 9 is a diagram showing an example of the state of the DC current cutoff device 1 in the scene where the common power transmission line LNc and the third DC power transmission line LN3 are electrically cut off in the first embodiment. As shown in FIG. 9, since the first mechanical contact 10-3, the second mechanical contact 20-3, and the auxiliary disconnector MS-3 are controlled in the open state, the common transmission line LNc and the third DC transmission line It is electrically cut off from LN3. As a result, the DC current cutoff device 1 suppresses the influence of the third DC transmission line LN3 by the abnormality occurring in the first DC transmission line LN1, and cuts off the DC current at the end of the third DC transmission line LN3. It is possible to continue supplying the power of the DC system existing on the end side other than the device 1 side.

[About total interruption of DC transmission line LN in the first direction]
FIG. 10 is a diagram showing an example of a state of the DC current cutoff device 1 in a scene where an abnormality occurs in the common power transmission line LNc. In the scene shown in FIG. 10, an abnormality has occurred in the common power transmission line LNc. Further, in the scene shown in FIG. 10, a DC system current in the first direction flows through the first DC power transmission line LN1, the second DC power transmission line LN2, and the third DC power transmission line LN3. The control unit 100 controls each unit of the DC current cutoff device 1 so as to cut off the common power transmission line LNc and the DC power transmission line LN.

FIG. 11 is a diagram showing an example of a state of the DC current cutoff device 1 in a situation where the DC transmission line LN through which the DC system current flows in the first direction is completely cut off in the first embodiment. The control unit 100 receives a cutoff instruction signal from the control system due to an abnormality in the common power transmission line LNc. In the scene shown in FIG. 11, the cutoff instruction signal electrically cuts off the DC power transmission line LN (in this case, all three lines) through which the DC system current in the first direction flows and the common power transmission line LNc. In this case, the control unit 100 controls each unit included in the DC current cutoff device 1 in the following states.
Auxiliary disconnector MS: closed state ・ 1st mechanical contact 10: open state ・ 2nd mechanical contact 20: open state ・ Switching

parts

310a and 310b of commutation circuit 30: off state ・ Switching part of commutation circuit 30 310c, 310d: On state / Semiconductor disconnector 40: Open state

By the control of the control unit 100 described above, the first mechanical contact 10 and the second mechanical contact 20 of the DC current cutoff device 1 are mechanically controlled to be in an open state, but even if the contacts are simply separated, they are between the contacts. Since an arc is generated in, it cannot be electrically shut off. In this state, when the control unit 100 operates the commutation circuit 30, the switching

units

310c and 310d included in the commutation circuit 30 are controlled to be on. Then, the commutation circuit 30 discharges the electric charge stored in the capacitor C from the positive electrode of the capacitor C to the negative electrode of the capacitor C via the switching unit 310c, the first mechanical contact 10, the reactor 80, and the switching unit 310d. A circuit is formed in which a current flows back through the paths (paths rt5 and rt8-rt9 shown in the figure). As a result, the current flowing through the first mechanical contact 10 becomes zero, and the first mechanical contact 10 is in an electrically cutoff state.

FIG. 12 is a diagram showing an example of a state of the DC current cutoff device 1 in the scene where the capacitor C is charged in the first embodiment. The control unit 100 charges the capacitor C of the commutation circuit 30 in preparation for the next reclosing as the first mechanical contact 10 is mechanically and electrically cut off. In order to transfer the DC system current to the first semiconductor circuit breaker 40-R that cuts off the DC system current in the direction, each part included in the DC current cutoff device 1 is controlled to the following state.
Auxiliary disconnector MS: closed state ・ 1st mechanical contact 10: open state ・ 2nd mechanical contact 20: open state ・ Switching

parts

310a and 310b of commutation circuit 30: off state ・ Switching part of commutation circuit 30 310c, 310d: Off state, 1st semiconductor circuit breaker 40-R: Closed state, 2nd semiconductor circuit breaker 40-L: Open state

Under the control of the control unit 100 described above, the DC system current flowing from the DC transmission line LN to the common transmission line LNc is the auxiliary disconnector MS, the reactor 80, the switching unit 310b, the capacitor C, the switching unit 310a, and the second mechanical contact. It flows via a path via 20 (path rt6, path rt10-rt11 in the figure). As a result, the DC current cutoff device 1 can charge the capacitor C included in the commutation circuit 30 and sufficiently output the current flowing back through the path rt5 and the path rt8-rt9 after the next reclosing.

Further, as the first semiconductor circuit breaker 40-R is controlled to the closed state, the DC system current flowing from the DC transmission line LN to the common transmission line LNc is the second diode 70 and the first semiconductor circuit breaker 40-. It flows via a path (path rt7, path rt12-rt13 in the figure) via the switching element of R. As a result, the DC current circuit breaker 1 gradually transfers the DC system current flowing from the DC transmission line LN to the path via the auxiliary disconnector MS, the commutation circuit 30, and the second mechanical contact 20 to the first semiconductor circuit breaker 40. It can be commutated to -R.

FIG. 13 is a diagram showing an example of a state of the DC current circuit breaker 1 in a scene where the DC system current according to the first embodiment is transferred to the semiconductor circuit breaker 40. In the scene of FIG. 13, the DC system current does not flow in the commutation circuit 30, and the DC system current flowing through the commutation circuit 30 and the second mechanical contact 20 in the common transmission line LNc is the second diode 70. , And the path rt7 and the path rt12-rt13 via the first semiconductor circuit breaker 40-R. Along with this, the arc of the second mechanical contact 20 is extinguished by the zero point of the current, and the second mechanical contact 20 is mechanically and electrically controlled to be in an open state.

The control unit 100 transfers each part of the DC current circuit breaker 1 after all of the DC system current in the first direction flowing from the DC power transmission line LN to the common power transmission line LNc is transferred to the first semiconductor circuit breaker 40-R. Control to the following states.
・ Auxiliary disconnector MS: closed state ・ 1st mechanical contact 10: open state ・ 2nd mechanical contact 20: open state ・ commutation circuit 30: off state ・ 1st semiconductor circuit breaker 40-R: closed state → open state State-Second semiconductor circuit breaker 40-L: Open state

The surge energy generated when the first semiconductor circuit breaker 40-R is controlled to the open state is absorbed by the arrester 50-R. As a result, the DC current cutoff device 1 can electrically cut off the common power transmission line LNc and the DC power transmission line LN. Then, the control unit 100 finally opens the auxiliary disconnector MS after the current flowing through the arrester 50-R becomes zero. When the auxiliary disconnector MS is controlled to the open state, no current is already flowing, so no arc is generated.

FIG. 14 is a diagram showing an example of the state of the DC current cutoff device 1 in a scene where the common power transmission line LNc and the DC power transmission line LN are electrically cut off. As shown in FIG. 14, since the first mechanical contact 10, the second mechanical contact 20, and the auxiliary disconnector MS are controlled in the open state, the common transmission line LNc and the DC transmission line LN are electrically cut off. Will be done. As a result, the DC current cutoff device 1 suppresses the influence of the DC transmission line LN due to an abnormality occurring in the common transmission line LNc, and is not the DC current cutoff device 1 side of the ends of each DC transmission line LN. The adverse effect on the DC system existing on the end side can be eliminated.

[Operation flow]
FIG. 15 is a flowchart showing an example of processing of the DC current cutoff device 1. First, the control unit 100 receives a cutoff instruction signal from the control system (step S100). The control unit 100 waits until the cutoff instruction signal is received. When the cutoff instruction signal is received, the control unit 100 determines whether or not the cutoff instruction signal indicates an instruction to cut off a plurality of DC transmission line LNs (that is, whether or not it is an individual cutoff) (step S102).

When the control unit 100 determines that the cutoff instruction signal is a signal instructing to cut off the plurality of DC power transmission line LNs, the control unit 100 is provided on the plurality of DC power transmission line LNs to be cut off instructed by the cutoff instruction signal. Each of the 1 mechanical contact 10 and the 2nd mechanical contact 20 is controlled to be in an open state (step S104). Next, the control unit 100 operates each of the commutation circuits 30 corresponding to the plurality of DC transmission line LNs to be cut off so as to cancel the current flowing through the DC transmission line LN to be cut off (step S106). Next, the control unit 100 controls the semiconductor circuit breaker 40 corresponding to the direction of the DC system current flowing through the target DC transmission line LN (that is, the transmission direction) in the closed state (step S108). The direction of the DC system current flowing through the target DC transmission line LN is the first direction or the second direction, and the semiconductor circuit breaker 40 corresponding to the first direction is the first semiconductor circuit breaker 40-R. The semiconductor circuit breaker 40 corresponding to the second direction is the second semiconductor circuit breaker 40-L. At this time, the DC power transmission line LNs that are cut off by the instruction indicated by the cutoff instruction signal are all DC power transmission line LNs in which the DC system current flows in the same direction.

The control unit 100 determines whether or not all of the DC system current flowing through the target DC transmission line LN has been transferred to the corresponding semiconductor circuit breaker 40 (step S110). The control unit 100 stands by until all of the DC system current flowing through the target DC transmission line LN is transferred to the corresponding semiconductor circuit breaker 40.

The control unit 100 determines the timing at which the DC system current is transferred to the semiconductor circuit breaker 40 based on the capacitor voltage of the capacitor C of the commutation circuit 30-1 and the current of the auxiliary circuit breaker MS-1. Alternatively, the determination may be made based on the elapse of a predetermined time after the cutoff operation of the target DC transmission line LN is started. In this way, when the semiconductor circuit breaker 40 is controlled to the closed state without performing the determination process, the control unit 100 does not have to perform the process of step S110.

When the control unit 100 determines that all of the DC system current flowing through the target DC transmission line LN has been transferred to the corresponding semiconductor circuit breaker 40 (if step S108 is not performed, the timing is predetermined. Or, when a predetermined time has elapsed), the corresponding semiconductor circuit breaker 40 is controlled to be in the open state (step S112). Next, the control unit 100 controls each of the auxiliary disconnector MSs provided in the plurality of DC transmission line LNs to be cut off in an open state (step S114). As a result, the DC current cutoff device 1 can cut off the plurality of target DC power transmission lines LN and the common power transmission line LNc.

When the control unit 100 determines that the cutoff instruction signal is a signal instructing individual cutoff, the control unit 100 has a first mechanical contact 10 provided on the DC transmission line LN to be cut off indicated by the cutoff instruction signal, and a first 2 The mechanical contact 20 is controlled to be in the open state (step S116). Next, the control unit 100 operates the commutation circuit 30 corresponding to the DC transmission line LN to be cut off so as to cancel the current flowing through the DC transmission line LN to be cut off (step S118). Next, the control unit 100 controls the semiconductor circuit breaker 40 corresponding to the direction of the DC system current flowing through the target DC transmission line LN (that is, the transmission direction) in the closed state (step S120). When the DC system current flowing through the target DC transmission line LN is transferred to the corresponding semiconductor circuit breaker 40, the control unit 100 controls the corresponding semiconductor circuit breaker 40 to be in an open state (step S122). Next, the control unit 100 controls the auxiliary disconnector MS provided in the DC transmission line LN to be cut off in an open state (step S124). As a result, the DC current cutoff device 1 can cut off one DC power transmission line LN to be cut off and the common power transmission line LNc.

[Summary of the first embodiment]
As described above, the DC current circuit breaker 1 of the present embodiment includes a plurality of first mechanical contacts 10 (in this example, first mechanical contacts 10-1 to 10-3) and a plurality of second machines. Formula contacts 20 (in this example, second mechanical contacts 20-1 to 20-3), a plurality of commutation circuits 30 (in this example, commutation circuits 30-1 to 30-3), and a first semiconductor. It has a circuit breaker 40-R and a second semiconductor circuit breaker 40-L. The first mechanical contact 10 is provided on each of a plurality of DC transmission line LNs (in this example, the first DC transmission line LN1, the second DC transmission line LN2, and the third DC transmission line LN3) constituting the DC system. .. The second mechanical contact 20 is provided between the plurality of first mechanical contacts 10 and the common power transmission line LNc commonly connected to the plurality of DC power transmission lines LN. In the plurality of commutation circuits 30-1 to 30-3, each commutation circuit 30 has a capacitor C, and one of the plurality of DC transmission line LNs is transferred from the DC transmission line LN to the common transmission line LNc. The current flowing in the first direction or the current flowing in the second direction from the common transmission line LNc to the DC transmission line LN is commutated. In the first semiconductor circuit breaker 40-R, the first end is connected to the common power transmission line LNc, the second end is connected to a plurality of DC power transmission lines LN, and the current flowing in the first direction in which the commutation circuit 30 is commutated. Can be blocked. The first end of the second semiconductor circuit breaker 40-L is connected to a plurality of DC power transmission lines LN, the second end is connected to the common power transmission line LNc, and the commutation circuit 30 flows in the second direction in which the commutation circuit 30 is commutated. The current can be cut off.

In the conventional DC current cutoff device, even if the commutation circuit can commutate the DC system current in the second direction flowing through the DC transmission line, it is difficult to transfer the DC system current in the first direction. .. Further, in the conventional DC current breaker, even if the semiconductor circuit breaker can cut off the DC system current in the second direction flowing through the DC transmission line, it is difficult to cut off the DC system current in the first direction. ..

According to the DC current breaker 1 of the present embodiment, the DC current in the first direction can be transferred to the first semiconductor circuit breaker 40-R by the commutation circuit 30 of the full bridge circuit, and the DC in the second direction is DC. The system current can be transferred to the second semiconductor circuit breaker 40-L. Further, according to the DC current cutoff device 1 of the present embodiment, the first semiconductor breaker 40-R can cut off the DC system current in the first direction, and the second semiconductor breaker 40-L can cut off the DC system in the second direction. The current can be cut off. Therefore, the DC current cutoff device 1 of the present embodiment can cut off the DC system current in both directions of the first direction and the second direction at the common transmission line LNc which is a coupling point of the plurality of DC transmission line LNs. ..

(Second embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings. In the first embodiment, the case where the DC current cutoff device 1 includes the commutation circuit 30 of the full bridge circuit has been described. In the second embodiment, the commutation circuit 30 is composed of a first commutation circuit 31 that commutates the DC system current in the first direction and a second commutation circuit 32 that commutates the DC system current in the second direction. The case where it is realized will be described. The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

[Configuration of DC current cutoff device 1a]
FIG. 16 is a diagram showing an example of the configuration of the DC current cutoff device 1a of the second embodiment. The commutation circuit 30 of the DC current cutoff device 1a is, for example, a first commutation circuit 31 that commutates a DC system current in the first direction and a second commutation circuit 32 that commutates a DC system current in the second direction. And. Further, the DC current cutoff device 1a includes first reactors 81-1 to 81-3 and second reactors 82-1 to 82-3 in place of the reactors 80-1 to 80-3. The first commutation circuit 31 is an example of the "first commutator circuit", and the second commutation circuit 32 is an example of the "second commutator circuit".

The first commutation circuit 31 includes, for example, a plurality of switching units (switching

units

310c and 310d shown), a plurality of diodes (

diodes

320a and 320b shown), and a capacitor C. The second commutation circuit 32 includes, for example, a plurality of switching units (switching

units

310a and 310b shown), a plurality of diodes (

diodes

320c and 320d shown), and a capacitor C.

In the first commutation circuit 31, the switching unit 310c and the diode 320a are connected in series between the positive electrode and the negative electrode of the first commutation circuit 31 in the order described, and the diode 320b and the switching unit 310d are connected. Are connected in series between the positive electrode and the negative electrode of the first commutation circuit 31 in the order described. The emitter of the switching unit 310c and the cathode of the diode 320a are connected to each other. The anode of the diode 320b and the collector of the switching unit 310d are connected to each other. The collector of the switching unit 310c, the cathode of the diode 320b, and the positive electrode of the capacitor C are connected to each other. The anode of the diode 320a, the emitter of the switching unit 310d, and the negative electrode of the capacitor C are connected to each other.

A first terminal 31a of the first commutation circuit 31 is provided at a connection point between the emitter of the switching unit 310c and the cathode of the diode 320a. A second terminal 31b of the first commutation circuit 31 is provided at a connection point between the anode of the diode 320b and the collector of the switching unit 310d.

In the second commutation circuit 32, the diode 320c and the switching unit 310a are connected in series between the positive electrode and the negative electrode of the commutation circuit 30 in the order described, and the switching unit 310b and the diode 320d are connected to each other. In the order described, the commutation circuit 30 is connected in series between the positive electrode and the negative electrode. The anode of the diode 320c and the collector of the switching unit 310a are connected to each other. The emitter of the switching unit 310b and the cathode of the diode 320d are connected to each other. The cathode of the diode 320c, the collector of the switching unit 310b, and the positive electrode of the capacitor C are connected to each other. The emitter of the switching unit 310a, the anode of the diode 320d, and the negative electrode of the capacitor C are connected to each other.

The first terminal 32a of the second commutation circuit 32 is provided at the connection point between the collector of the switching unit 310a and the anode of the diode 320c. A second terminal 32b of the second commutation circuit 32 is provided at a connection point between the emitter of the switching unit 310b and the cathode of the diode 320d.

The first terminal 31a of the first commutation circuit 31 and the first terminal 32a of the second commutation circuit 32 are connected to the same locations as the first terminal 30a described above.

The second terminal 31b of the first commutation circuit 31, the anode of the second diode 70, and one end of the second reactor 82 are connected to each other. Further, the other end of the second reactor 82, the second terminal 10b of the first mechanical contact 10, and the first terminal MSa of the auxiliary disconnector MS are connected to each other.

The second terminal 32b of the second commutation circuit 32, the cathode of the first diode 60, and one end of the first reactor 81 are connected to each other. Further, the other end of the first reactor 81, the second terminal 10b of the first mechanical contact 10, and the first terminal MSa of the auxiliary disconnector MS are connected to each other.

In a state where the common power transmission line LNc and the DC power transmission line LN are electrically conducted by the DC current cutoff device 1a (hereinafter, a normal conduction state), each part is in the following state.
・ Auxiliary circuit breaker MS: closed state ・ 1st mechanical contact 10: closed state ・ 2nd mechanical contact 20: closed state ・ 1st commutation circuit 31: off state ・ 2nd commutation circuit 32: off state ・ No. 1 Capacitor C included in commutation circuit 31: charged state ・ Capacitor C included in second commutation circuit 32: charged state ・ Semiconductor circuit breaker 40: open state The following is the details of control of the DC current circuit breaker 1a. explain.

[Individual cutoff in the second direction]
In the scene shown in FIG. 16, an abnormality has occurred in the first DC power transmission line LN1. When the control unit 100 receives a cutoff instruction signal from the control system, the control unit 100 controls the first mechanical contact 10 and the second mechanical contact 20 provided on the target DC transmission line LN in an open state, and controls the target DC in an open state. A switching unit according to the direction of the DC system current flowing through the transmission line LN, which is included in the switching

units

310c, 310d, or the second commutation circuit 32 included in the first commutation circuit 31 related to the target DC transmission line LN. One of the switching

units

310a and 310b is controlled to be in the ON state.

In the scene shown in FIG. 16, it is shown that the cutoff instruction signal electrically cuts off the first DC power transmission line LN1 and the common power transmission line LNc. When the DC system current flowing through the DC transmission line LN to be cut off (in this case, the first DC transmission line LN1) is in the second direction, the control unit 100 includes the following parts of the DC current cutoff device 1a as follows. Control to state. The operation of the first commutation circuit 31 and the second commutation circuit 32 when the DC system current is in the first direction will be described later.
Auxiliary disconnector MS-1: Closed state-First mechanical contact 10-1: Open state-Second mechanical contact 20-1: Open state-First commutation circuit 31-1: Off state-Second roll Flow circuit 32-1: On state / Semiconductor disconnector 40: Open state (The configuration related to the second DC transmission line LN2 and the configuration related to the third DC transmission line LN3 remain in the above-mentioned normal conduction state).

By the control of the control unit 100 described above, the first mechanical contact 10-1 and the second mechanical contact 20-1 of the DC current cutoff device 1a are mechanically controlled to be in the open state, but the contacts are simply separated. However, since an arc is generated between the contacts, it cannot be electrically cut off. In this state, when the control unit 100 operates the second commutation circuit 32-1, the switching

units

310a and 310b included in the second commutation circuit 32-1 are controlled to be in the ON state. Then, the second commutation circuit 32-1 discharges the electric charge stored in the capacitor C, and the switching unit 310b, the first reactor 81-1, the first mechanical contact 10-1, and the switching from the positive electrode of the capacitor C. A circuit is formed in which a current returns through the path rt14 to the negative electrode of the capacitor C via the portion 310a. As a result, the current flowing through the first mechanical contact 10-1 becomes zero, and the first mechanical contact 10-1 is in an electrically cut-off state.

FIG. 17 is a diagram showing an example of a state of the DC current cutoff device 1a in a scene where the capacitor C is charged in the second embodiment. The control unit 100 sets the capacitor C of the second commutation circuit 32-1 in preparation for the next reclosing circuit as the first mechanical contact 10-1 is mechanically and electrically cut off. In order to transfer the DC system current to the second semiconductor circuit breaker 40-L that cuts off the DC system current in the second direction while charging, each part of the DC current cutoff device 1a is controlled to the following state.
-Auxiliary disconnector MS-1: Closed state-First mechanical contact 10-1: Open state-Second mechanical contact 20-1: Open state-First commutation circuit 31-1: Off state-Second roll Flow circuit 32-1: Off state ・ First semiconductor circuit breaker 40-R: Open state ・ Second semiconductor circuit breaker 40-L: Closed state (configuration related to the second DC transmission line LN2 and the third DC transmission line LN3) The configuration according to the above is the normal conduction state described above.)

Under the control of the control unit 100 described above, the DC system current flowing from the common transmission line LNc to the first DC transmission line LN1 is the second mechanical contact 20-1, the diode 320c of the second commutation circuit 32-1, and the capacitor C. , The diode 320d, and the path rt15 via the first reactor 81-1. As a result, the DC current cutoff device 1a can charge the capacitor C included in the second commutation circuit 32-1 and sufficiently output the current flowing back through the path rt14 after the next reclosing.

Further, as the second semiconductor circuit breaker 40-L is controlled to the closed state, the DC system current flowing from the common power transmission line LNc to the first DC power transmission line LN1 becomes the second semiconductor circuit breaker 40-L and the second semiconductor circuit breaker 40-L. 1 It joins the path rt15 via the path rt16 via the diode 60-1. As a result, the DC current cutoff device 1a flows from the common transmission line LNc to the path via the second mechanical contact 20-1, the second commutation circuit 32-1, and the auxiliary disconnector MS-1. Can be gradually commutated to the second semiconductor circuit breaker 40-L.

FIG. 18 is a diagram showing an example of a state of the DC current circuit breaker 1a in a scene where the DC system current according to the second embodiment is transferred to the semiconductor circuit breaker 40. The DC system current stopped flowing through the second commutation circuit 32-1, and the DC system was flowing through the first DC transmission line LN1 via the second mechanical contact 20-1 and the second commutation circuit 32-1. The current is transferred to the path rt16 via the second semiconductor circuit breaker 40-L and the first diode 60-1. Along with this, the arc of the second mechanical contact 20-1 is extinguished by the zero point of the current, and the second mechanical contact 20-1 is mechanically and electrically controlled to be in an open state.

After the DC system current in the second direction flowing from the common power transmission line LNc to the first DC power transmission line LN1 is transferred to the second semiconductor circuit breaker 40-L, the control unit 100 sets each part of the DC current cutoff device 1a. Control to the following states.
-Auxiliary disconnector MS-1: Closed state-First mechanical contact 10-1: Open state-Second mechanical contact 20-1: Open state-First commutation circuit 31-1: Off state-Second roll Flow circuit 32-1: Off state ・ First semiconductor circuit breaker 40-R: Open state ・ Second semiconductor circuit breaker 40-L: Closed state → Open state (configuration related to the second DC transmission line LN2 and the third DC The configuration related to the transmission line LN3 remains in the normal conduction state described above.)

The surge energy generated when the second semiconductor circuit breaker 40-L is controlled to the open state is absorbed by the arrester 50-L. As a result, the DC current cutoff device 1a can electrically cut off the common power transmission line LNc and the first DC power transmission line LN1. Then, the control unit 100 finally opens the auxiliary disconnector MS-1 after the current flowing through the arrester 50-L becomes zero. When the auxiliary disconnector MS-1 is controlled to the open state, no current is already flowing, so no arc is generated.

FIG. 19 is a diagram showing an example of a state of the DC current cutoff device 1a in a scene where the common power transmission line LNc and the first DC power transmission line LN1 are electrically cut off in the second embodiment.

[Individual cutoff in the first direction]
FIG. 20 is a diagram showing an example of a state of the DC current cutoff device 1a in a scene in which the third DC transmission line LN3 through which the DC system current flows in the first direction is individually cut off in the second embodiment. In the scene shown in FIG. 20, an abnormality has occurred in the first DC power transmission line LN1. The control unit 100 receives a cutoff instruction signal from the control system.

In the scene shown in FIG. 20, it is shown that the cutoff instruction signal electrically cuts off the third DC power transmission line LN3 and the common power transmission line LNc. When the DC system current flowing through the DC transmission line LN to be cut off (in this case, the third DC transmission line LN3) is in the first direction, the control unit 100 includes the following parts of the DC current cutoff device 1a as follows. Control to state.
-Auxiliary disconnector MS-3: Closed state-First mechanical contact 10-3: Open state-Second mechanical contact 20-3: Open state-First commutation circuit 31-3: On state-Second roll Flow circuit 32-3: Off state / Semiconductor disconnector 40: Open state (The configuration related to the first DC transmission line LN1 and the configuration related to the second DC transmission line LN2 remain in the above-mentioned normal conduction state).

By the control of the control unit 100 described above, the first mechanical contact 10-3 and the second mechanical contact 20-3 of the DC current cutoff device 1a are mechanically controlled to be in the open state, but the contacts are simply separated. However, since an arc is generated between the contacts, it cannot be electrically cut off. In this state, when the control unit 100 operates the first commutation circuit 31-3, the switching

units

310c and 310d included in the first commutation circuit 31-3 are controlled to be in the ON state. Then, the first commutation circuit 31-3 discharges the electric charge stored in the capacitor C, and the switching unit 310c, the first mechanical contact 10-3, the second reactor 82-3, and the switching from the positive electrode of the capacitor C. A circuit is formed in which a current returns through the path rt17 to the negative electrode of the capacitor C via the unit 310d. As a result, the current flowing through the first mechanical contact 10-3 becomes zero, and the first mechanical contact 10-3 is in an electrically cutoff state.

FIG. 21 is a diagram showing an example of the state of the DC current cutoff device 1a in the scene where the capacitor C is charged in the second embodiment. The control unit 100 sets the capacitor C of the first commutation circuit 31-3 in preparation for the next reclosing as the first mechanical contact 10-3 is mechanically and electrically cut off. In order to transfer the DC system current to the first semiconductor circuit breaker 40-R that cuts off the DC system current in the first direction while charging, each part of the DC current cutoff device 1a is controlled to the following state.
-Auxiliary disconnector MS-3: Closed state-First mechanical contact 10-3: Open state-Second mechanical contact 20-3: Open state-First commutation circuit 31-3: Off state-Second roll Flow circuit 32-3: Off state-First semiconductor circuit breaker 40-R: Closed state-Second semiconductor circuit breaker 40-L: Open state (configuration related to the first DC transmission line LN1 and the second DC transmission line LN2 The configuration according to the above is the normal conduction state described above.)

Under the control of the control unit 100 described above, the DC system current flowing from the third DC transmission line LN3 to the common transmission line LNc is the auxiliary circuit breaker MS-3, the second reactor 82-3, the diode 320b, the capacitor C, and the diode 320a. And flows via the path rt18 via the second mechanical contact 20-3. As a result, the DC current cutoff device 1a can charge the capacitor C included in the first commutation circuit 31-3 and sufficiently output the current flowing back through the path rt17 after the next reclosing.

Further, as the first semiconductor circuit breaker 40-R is controlled to the closed state, the DC system current flowing from the third DC transmission line LN3 to the common transmission line LNc is the second diode 70-3 and the first semiconductor. It flows through the path rt19 via the switching element of the circuit breaker 40-R. As a result, the DC current cutoff device 1a causes the DC current to flow from the third DC transmission line LN3 to the path via the auxiliary disconnector MS-3, the first commutation circuit 31-3, and the second mechanical contact 20-3. Can be gradually commutated to the first semiconductor circuit breaker 40-R.

FIG. 22 is a diagram showing an example of a state of the DC current circuit breaker 1a in a scene where the DC system current according to the second embodiment is transferred to the semiconductor circuit breaker 40. The DC system current does not flow through the first commutation circuit 31-3, and the DC system current flowing through the common transmission line LNc via the first commutation circuit 31-3 and the second mechanical contact 20-3 flows. , The second diode 70-3, and the first semiconductor circuit breaker 40-R, are commutated to the path rt19. Along with this, the arc of the second mechanical contact 20-3 is extinguished by the zero point of the current, and the second mechanical contact 20-3 is mechanically and electrically controlled to be in an open state.

The control unit 100 transfers each part of the DC current circuit breaker 1a after the DC system current in the first direction flowing from the third DC power transmission line LN3 to the common power transmission line LNc is transferred to the first semiconductor circuit breaker 40-R. Control to the following states.
-Auxiliary disconnector MS-3: Closed state-First mechanical contact 10-3: Open state-Second mechanical contact 20-3: Open state-First commutation circuit 31-3: Off state-Second roll Flow circuit 32-3: Off state-First semiconductor circuit breaker 40-R: Closed state-> Open state-Second semiconductor circuit breaker 40-L: Open state (configuration related to the first DC transmission line LN1 and the second DC The configuration related to the transmission line LN2 remains in the normal conduction state described above.)

The surge energy generated when the first semiconductor circuit breaker 40-R is controlled to the open state is absorbed by the arrester 50-R. As a result, the DC current cutoff device 1a can electrically cut off the common power transmission line LNc and the third DC power transmission line LN3. Then, the control unit 100 finally opens the auxiliary disconnector MS-3 after the current flowing through the arrester 50-R becomes zero. When the auxiliary disconnector MS-3 is controlled to the open state, no current is already flowing, so no arc is generated.

FIG. 23 is a diagram showing an example of the state of the DC current cutoff device 1a in a scene where the common power transmission line LNc and the third DC power transmission line LN3 are electrically cut off.

[About total interruption of DC transmission line LN in the first direction]
FIG. 24 is a diagram showing an example of a state of the DC current cutoff device 1a in a scene where an abnormality occurs in the common power transmission line LNc. In the scene shown in FIG. 24, an abnormality has occurred in the common power transmission line LNc. Further, in the scene shown in FIG. 24, a DC system current in the first direction flows through the first DC power transmission line LN1, the second DC power transmission line LN2, and the third DC power transmission line LN3. The control unit 100 controls each unit of the DC current cutoff device 1a so as to cut off the common power transmission line LNc and the DC power transmission line LN.

FIG. 25 is a diagram showing an example of a state of the DC current cutoff device 1a in a scene where the DC transmission line LN through which the DC system current flows in the first direction is completely cut off in the second embodiment. The control unit 100 receives a cutoff instruction signal from the control system due to an abnormality in the common power transmission line LNc. In the scene shown in FIG. 25, the cutoff instruction signal electrically cuts off the DC power transmission line LN (in this case, all three lines) through which the DC system current in the first direction flows and the common power transmission line LNc. In this case, the control unit 100 controls each unit included in the DC current cutoff device 1a in the following states.
-Auxiliary disconnector MS: Closed state-First mechanical contact 10: Open state-Second mechanical contact 20: Open state-First commutation circuit 31: On state-Second commutation circuit 32: Off state-Semiconductor Disconnector 40: Open state

By the control of the control unit 100 described above, the first mechanical contact 10 and the second mechanical contact 20 of the DC current cutoff device 1a are mechanically controlled to be in an open state, but even if the contacts are simply separated, the contacts are separated from each other. Since an arc is generated in, it cannot be electrically shut off. In this state, when the control unit 100 operates the first commutation circuit 31, the switching

units

310c and 310d included in the first commutation circuit 31 are controlled to be on. Then, the first commutation circuit 31 discharges the electric charge stored in the capacitor C, and from the positive electrode of the capacitor C, the capacitor is passed through the switching section 310c, the first mechanical contact 10, the second reactor 82, and the switching section 310d. A circuit is formed in which a current flows back through the path to the negative electrode of C (path rt17, path rt20-rt21 in the figure). As a result, the current flowing through the first mechanical contact 10 becomes zero, and the first mechanical contact 10 is in an electrically cutoff state.

FIG. 26 is a diagram showing an example of the state of the DC current cutoff device 1a in the scene where the capacitor C is charged in the second embodiment. The control unit 100 charges the capacitor C of the first commutation circuit 31 in preparation for the next reclosing as the first mechanical contact 10 is mechanically and electrically cut off. In order to transfer the DC system current to the first semiconductor circuit breaker 40-R that cuts off the DC system current in the first direction, each part of the DC current cutoff device 1a is controlled to the following state.
・ Auxiliary disconnector MS: closed state ・ 1st mechanical contact 10: open state ・ 2nd mechanical contact 20: open state ・ 1st commutation circuit 31: off state ・ 2nd commutation circuit 32: off state ・ No. 1 Semiconductor disconnector 40-R: Closed state, 2nd semiconductor circuit breaker 40-L: Open state

Under the control of the control unit 100 described above, the DC system current flowing from the DC transmission line LN to the common transmission line LNc is the auxiliary disconnector MS, the second reactor 82, the diode 320b, the capacitor C, the diode 320a, and the second mechanical contact. It flows via a path via 20 (path rt18, path rt22-rt23 in the figure). As a result, the DC current cutoff device 1a can charge the capacitor C included in the first commutation circuit 31 and sufficiently output the current flowing back through the path rt17 and the path rt20-rt21 after the next reclosing.

Further, as the first semiconductor circuit breaker 40-R is controlled to the closed state, the DC system current flowing from the DC transmission line LN to the common transmission line LNc is the second diode 70 and the first semiconductor circuit breaker 40-. It flows via a path (path rt19, path rt24-rt25 in the figure) via the switching element of R. As a result, the DC current cutoff device 1a gradually cuts off the DC system current flowing from the DC transmission line LN to the path via the auxiliary disconnector MS, the first commutation circuit 31, and the second mechanical contact 20. It can be commutated to the vessel 40-R.

FIG. 27 is a diagram showing an example of a state of the DC current circuit breaker 1a in a scene where the DC system current according to the second embodiment is transferred to the semiconductor circuit breaker 40. The direct current system current does not flow in the first commutation circuit 31, and the direct current system current flowing in the common transmission line LNc via the first commutation circuit 31 and the second mechanical contact 20 is transferred to the second diode 70. And, it is commutated to the path rt19 and the path rt24-rt25 via the first semiconductor circuit breaker 40-R. Along with this, the arc of the second mechanical contact 20 is extinguished by the zero point of the current, and the second mechanical contact 20 is mechanically and electrically controlled to be in an open state.

The control unit 100 transfers each part of the DC current circuit breaker 1a after all of the DC system current in the first direction flowing from the DC power transmission line LN to the common power transmission line LNc is transferred to the first semiconductor circuit breaker 40-R. Control to the following states.
・ Auxiliary disconnector MS: closed state ・ 1st mechanical contact 10: open state ・ 2nd mechanical contact 20: open state ・ 1st commutation circuit 31: off state ・ 2nd commutation circuit 32: off state ・ No. 1 Semiconductor disconnector 40-R: Closed state → Open state ・ Second semiconductor circuit breaker 40-L: Open state

FIG. 28 is a diagram showing an example of the state of the DC current cutoff device 1a in a scene where the common power transmission line LNc and the DC power transmission line LN are electrically cut off. As shown in FIG. 28, since the first mechanical contact 10, the second mechanical contact 20, and the auxiliary disconnector MS are controlled in the open state, the common transmission line LNc and the DC transmission line LN are electrically cut off. Will be done.

[Combination of DC transmission line LN to be cut off]
In the above description, the DC current cutoff device 1 and the DC current cutoff device 1a are any one of the first DC transmission line LN1, the second DC transmission line LN2, and the third DC transmission line LN3. The case where the LN and the common transmission line LNc are cut off (that is, individual cutoff) or all the DC power transmission line LN and the common power transmission line LNc are cut off (that is, all cutoff) has been described, but the present invention is not limited to this. .. The DC current cutoff device 1 and the DC current cutoff device 1a cut off, for example, two or more DC transmission line LNs in which a DC system current flows in the same direction and a common transmission line LNc among the DC transmission line LNs. It may be.

For example, in the scenes shown in FIGS. 2 and 16, a DC system current flows in the second direction between the first DC power transmission line LN1 and the second DC power transmission line LN2. In this case, the DC current cutoff device 1 and the DC current cutoff device 1a may cut off the first DC power transmission line LN1 and the second DC power transmission line LN2 and the common power transmission line LNc. The process of shutting off the second DC power transmission line LN2 in the scenes of FIGS. 2 and 16 is the same as the process of shutting off the first DC power transmission line LN1 in the scenes of FIGS. 2 and 16. In this case, the control unit 100 transfers both the DC system current flowing through the first DC transmission line LN1 and the DC system current flowing through the second DC transmission line LN2 to the second semiconductor circuit breaker 40-L. , The second semiconductor circuit breaker 40-L is controlled to be in the open state. As a result, the DC current cutoff device 1 and the DC current cutoff device 1a have two or more DC transmission line LNs (in this case, the first DC transmission line) in which the DC system current flows in the same direction (in this case, the second direction). The LN1 and the second DC transmission line LN2) and the common transmission line LNc can be cut off.

In this example, the case where the same DC system current in the second direction flows through the first DC transmission line LN1 and the second DC transmission line LN2 has been described, but the present invention is not limited to this. The DC current cutoff device 1 and the DC current cutoff device 1a are the first DC transmission line LN1 in the scene where the same second-direction DC system current flows through the first DC transmission line LN1 and the third DC transmission line LN3. , And the third DC transmission line LN3 and the common transmission line LNc may be cut off. Further, in the scene where the DC system current in the first direction flows through the first DC transmission line LN1 and the DC system current in the second direction flows through the second DC transmission line LN2 and the third DC transmission line LN3, DC is applied. The current cutoff device 1 and the DC current cutoff device 1a may cut off the second DC transmission line LN2, the third DC transmission line LN3, and the common transmission line LNc.

Further, in the scenes shown in FIGS. 6 and 20, only the third DC transmission line LN3 has a DC system current flowing in the first direction, and the first DC transmission line LN1 and the second DC transmission line LN2 have a second DC transmission line. The case where the DC system current is flowing in the direction has been described, but the present invention is not limited to this, and in the scenes shown in FIGS. 6 and 20, the second DC transmission line LN2 and the third DC transmission line LN3 are in the first direction. When the DC system current is flowing and the DC system current in the second direction is flowing through the first DC transmission line LN1, the third DC transmission line LN3, the second DC transmission line LN2, and the common transmission line LNc And may be blocked. The process of shutting off the second DC power transmission line LN2 in the scenes of FIGS. 6 and 20 is the same as the process of shutting off the third DC power transmission line LN3 in the scene of FIGS. 6 and 20. In this case, in the control unit 100, both the DC system current flowing through the third DC transmission line LN3 and the DC system current flowing through the second DC transmission line LN2 are transferred to the first semiconductor circuit breaker 40-R. After that, the first semiconductor circuit breaker 40-R is controlled to be in the open state. As a result, the DC current cutoff device 1 has two or more DC transmission line LNs (in this case, the third DC transmission line LN3 and the second DC transmission) in which the DC system current flows in the same direction (in this case, the first direction). The line LN2) and the common transmission line LNc can be cut off.

Further, in the scene where the DC system current in the first direction flows through the first DC transmission line LN1 and the third DC transmission line LN3, and the DC system current in the second direction flows through the second DC transmission line LN2, The DC current cutoff device 1 and the DC current cutoff device 1a may cut off the first DC transmission line LN1 and the third DC transmission line LN3 and the common transmission line LNc. The process of interrupting the DC transmission line LN through which the DC system current in the first direction flows and the common transmission line LNc by these combinations is the same as the above-mentioned process, and the hyphen and the following at the end of the code may be replaced. Therefore, the description thereof will be omitted.

[About the position where the reactor is installed]
In the DC current circuit breaker 1 and the DC current circuit breaker 1a, the reactor component of the reactor 80 is the commutation operation of the commutation circuit 30, the first semiconductor circuit breaker 40-R, and the second semiconductor circuit breaker 40-. It may be provided at a position that acts on the blocking operation of L.

FIG. 29 is a diagram showing another example of the position of the reactor 80 in the DC current cutoff device 1. In FIG. 29, one end of the reactor 80, the second terminal 30b of the commutation circuit 30, the cathode of the first diode 60, and the anode of the second diode 70 are connected to each other, and the other end of the reactor 80 and the first The two terminals 20b are connected to each other. When the inductance 80 is provided at this position, the reactor component of the reactor 80 causes recirculation associated with the operation of the commutation circuit 30 in the path rt26, and is commutated to the first semiconductor circuit breaker 40-R in the first direction. The inductance of the DC system current path rt27 and the second direction DC system current path rt28 commutated to the second semiconductor circuit breaker 40-L can be unified.

FIG. 30 is a diagram showing another example of the position of the reactor in the DC current cutoff device 1a. In FIG. 30, the DC current cutoff device 1a includes third reactors 83-1 to 83-3 in place of the first reactors 81-1 to 81-3 and the second reactors 82-1 to 82-3. .. One end of the third reactor 83, the second terminal 31b of the first commutation circuit 31, the anode of the second diode 70, the second terminal 32b of the second commutation circuit 32, and the cathode of the first diode 60 They are connected to each other, and the other end of the third reactor 83 and the second terminal 20b are connected to each other. By providing the third reactor 83 at this position, the reactor component of the third reactor 83 causes the recirculation associated with the operation of the first commutation circuit 31 to occur in the path rt29, or to the operation of the second commutation circuit 32. The path rt31 of the DC system current in the first direction commutated to the first semiconductor circuit breaker 40-R and the second direction commutated to the second semiconductor circuit breaker 40-L while causing the accompanying reflux in the path rt30. The inductance of the DC system current with the path rt32 can be unified.

Here, when the reactor 80 is provided at the conventional position, the reactor component of the reactor 80 acts on the commutation circuit 30 and the DC system current in the second direction commutated to the second semiconductor circuit breaker 40-L. However, it did not act on the DC system current in the first direction commutated to the first semiconductor circuit breaker 40-R. In this case, since the inductance of each DC transmission line LN depends on the parasitic reactor of each DC transmission line LN, the DC current breaker 1 uses the DC current cutoff speed of the first semiconductor circuit breaker 40-R and the second semiconductor. It was not possible to unify or adjust the DC system current cutoff speed of the circuit breaker 40-L. On the other hand, by providing the reactor 80 at the position shown in FIG. 29, the DC current breaker 1 has the DC current cutoff speed of the first semiconductor circuit breaker 40-R and the DC current cutoff speed of the second semiconductor circuit breaker 40-L. The DC system current cutoff speed can be unified or adjusted.

Further, by providing the first reactor 81 and the second reactor 82 at the positions of the third reactor 83, the DC current circuit breaker 1a has the first commutation circuit 31 and the second commutation circuit 31 while reducing the number of parts. The third reactor 83 is made to act on the commutation operation of the flow circuit 32 to unify the DC system current cutoff speed of the first semiconductor circuit breaker 40-R and the DC system current cutoff speed of the second semiconductor circuit breaker 40-L, or Can be adjusted.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

Claims

A plurality of first mechanical contacts provided on each of the plurality of DC transmission lines constituting the DC system, and
A second mechanical contact provided between the plurality of first mechanical contacts and a common power transmission line commonly connected to the plurality of DC power transmission lines, and
A plurality of commutation circuits, each commutation circuit having a capacitor, and a current flowing in a first direction from one of the plurality of DC transmission lines to the common transmission line, or A plurality of commutation circuits that commutate the current flowing in the second direction from the common transmission line to the DC transmission line.
A first semiconductor circuit breaker whose first end is connected to the common power transmission line, whose second end is connected to the plurality of DC power transmission lines, and which can cut off the current flowing in the first direction to which the commutation circuit has commutated. When,
A second semiconductor circuit breaker capable of interrupting the current flowing in the second direction to which the commutation circuit is commuted, the first end being connected to each of the plurality of DC transmission lines and the second end being connected to the common transmission line. With a vessel
DC current breaker equipped with.
Each of the plurality of commutation circuits has a plurality of switching elements.
Further, a control unit for controlling the open / closed state of the plurality of switching elements in the plurality of commutation circuits is provided.
When the control unit turns off a part or all of the plurality of first mechanical contacts,
A part of the switching elements among the plurality of switching elements is turned on to put the commutation circuit into an operating state, and the electric charge charged in the capacitor is used to flow in the first direction or in the second direction. After commutating at least one of the flowing currents
All of the plurality of switching elements are turned off to stop the commutation circuit, and the current flowing in the first direction and the current flowing in the second direction are not commutated.
The DC current cutoff device according to claim 1.
Each of the plurality of commutation circuits includes a first commutator circuit that commutates a current flowing in the first direction and a second commutator circuit that commutates a current flowing in the second direction.
The DC current cutoff device according to claim 1.
Each of the plurality of commutation circuits further includes a plurality of switching elements and a plurality of diodes.
A control unit for controlling the open / closed state of the switching element is further provided.
The control unit
The plurality of switching elements are turned on to put the commutation circuit into an operating state, and the electric charge charged in the capacitor is used to rotate at least one of the current flowing in the first direction and the current flowing in the second direction. After letting it flow
All of the plurality of switching elements are controlled to be in the off state to stop the commutation circuit, and the current flowing in the first direction and the current flowing in the second direction are not commutated.
The direct current cutoff device according to claim 3.
A plurality of DC transmission lines provided between the second end of the first semiconductor circuit breaker and the plurality of DC power transmission lines, and between the second end of the second semiconductor circuit breaker and the plurality of DC power transmission lines, respectively. With more reactors
The commutation circuit constitutes a closed circuit by the reactor and the capacitor, and commutates a current between the common transmission line and the DC transmission line.
The DC current cutoff device according to any one of claims 2 to 4.
The commutation circuit constitutes a closed circuit by the reactor component of the DC transmission line and the capacitor, and commutates a current between the common transmission line and the DC transmission line.
The DC current cutoff device according to any one of claims 2 to 4.
The open / closed state of the first mechanical contact, the open / closed state of the second mechanical contact, the operation of the commutation circuit, the open / closed state of the first semiconductor circuit breaker, and the open / closed state of the second semiconductor circuit breaker. Further equipped with a control unit to control and
The control unit
When the plurality of DC power transmission lines and the common power transmission line are electrically conducted, both the first mechanical contact and the second mechanical contact are controlled to be in a closed state, and the commutation circuit is operated. Both are stopped, and both the first semiconductor circuit breaker and the second semiconductor circuit breaker are controlled to be in the open state.
When the target DC transmission line and the common transmission line are electrically cut off from the plurality of DC transmission lines, the first mechanical contact and the second mechanical contact provided on the target DC transmission line are provided. The mechanical contact is controlled to be open, and the commutation circuit corresponding to the target DC transmission line is put into an operating state.
When the current flowing through the target DC transmission line is the current in the first direction, the target DC transmission is performed to the first semiconductor breaker by the commutation circuit with the first semiconductor circuit breaker closed. After the current flowing through the line is commutated, the first semiconductor circuit breaker is controlled to be in an open state to electrically cut off the target DC transmission line and the common transmission line.
When the current flowing through the target DC transmission line is the current in the second direction, the target DC power transmission is performed to the second semiconductor circuit breaker by the commutation circuit with the second semiconductor circuit breaker closed. After the current flowing through the line is commutated, the second semiconductor circuit breaker is controlled to be in an open state to electrically cut off the target DC transmission line and the common transmission line.
The DC current cutoff device according to any one of claims 1 to 6.
The open / closed state of the first mechanical contact, the open / closed state of the second mechanical contact, the operation of the commutation circuit, the open / closed state of the first semiconductor circuit breaker, and the open / closed state of the second semiconductor circuit breaker. Further equipped with a control unit to control and
The control unit
When the plurality of DC power transmission lines and the common power transmission line are electrically conducted, both the first mechanical contact and the second mechanical contact are controlled to be in a closed state, and the commutation circuit is operated. Both are stopped, and both the first semiconductor circuit breaker and the second semiconductor circuit breaker are controlled to be in the open state.
When the currents flowing through the plurality of DC power transmission lines are all in the same direction and both the plurality of DC power transmission lines and the common power transmission line are electrically cut off, the plurality of first mechanical contacts are used. And the second mechanical contact are both controlled to be in the open state, and the commutation circuit is put into the operating state.
When all of the currents flowing through the plurality of DC transmission lines are currents in the first direction, the first semiconductor circuit breaker is closed and any of the currents flowing through the plurality of DC transmission lines is used. After being commutated to the first semiconductor circuit breaker by the commutation circuit, the first semiconductor circuit breaker is controlled to be in an open state to electrically cut off the plurality of DC transmission lines and the common transmission line. ,
When all of the currents flowing through the plurality of DC transmission lines are currents in the second direction, the second semiconductor circuit breaker is closed and any of the currents flowing through the plurality of DC transmission lines is used. After being commutated to the second semiconductor circuit breaker by the commutation circuit, the second semiconductor circuit breaker is controlled to be in an open state to electrically cut off the plurality of DC transmission lines and the common transmission line. ,
The DC current cutoff device according to any one of claims 1 to 7.