JP7478689B2 - Switchgear - Google Patents

Description

The present invention relates to a switchgear (switchgear device) that opens and closes high-voltage distribution circuits.

Switchgear (switchgear) is used to open and close high voltage, e.g. 24 kV, distribution circuits, and contains circuit breakers, disconnecting switches, grounding devices, etc., in a metal box. Here, circuit breakers are devices that open and close electric circuits, making it possible to interrupt the current in the circuit, and have the ability to extinguish arcs. Disconnecting switches are devices that open and close voltages when no current is flowing, for maintenance inspections, etc. Grounding devices are devices that ground electric circuits to provide them with earth potential.

Patent Document 1 discloses a switch gear that is composed of a vacuum valve with freely connectable and disconnectable contacts, a ground disconnecting section with a movable electrode, a flexible conductor that connects an intermediate fixed electrode of the ground disconnecting section to the movable side of the vacuum valve, a vacuum valve operating rod, and a ground disconnecting section operating rod, in which the vacuum valve and part of the ground disconnecting section, including the busbar bushing and cable bushing, are integrally cast with a solid insulating material (see Figure 1).

In the event of an accident, the switchgear first cuts off the current at the breaker section, then disconnects it at the disconnecting section. It is then configured to ensure safety by grounding the circuit with a grounding device.

JP 2016-208809 A

To make switchgear smaller, it is common to integrate the circuit breaker, disconnecting unit, and earthing device in a highly insulating resin. However, when they are integrated, when inspecting the operation of the circuit breaker, it is necessary to cut off power to both the bus side that receives the power and the power receiving side (power distribution side) that consumes the power, or to remove both cables.

Let us explain this point further. The receiving cable and the equipment connected to it have capacitance. Therefore, even if the power is cut off on the busbar side of the circuit breaker or the cable on the busbar side is removed, if the receiving cable is connected to the disconnecting section, there is a risk that voltage will be applied to the disconnecting section. And when workers inspect the circuit breaker, they may be electrocuted by the disconnecting section. Therefore, when inspecting the operation of the circuit breaker, it is necessary to cut off the power on the receiving side and remove the cable, which makes the work complicated.

The switchgear described in Patent Document 1 is constructed by casting the vacuum valve of the breaker and part of the earth disconnection section as a single unit using solid insulating material, and does not take into consideration the possibility of inspecting the operation of the breaker without causing a power outage on the power receiving side or removing the cable.

The present invention was made based on the above, and aims to provide a switchgear that can check the operation of the circuit breaker by shutting down only the busbar side, without shutting down the power on the power receiving side or removing the power receiving cable.

To give an example of the "switchgear" of the present invention for solving the above problem,
In a switchgear housing a circuit breaker and a disconnector in a box, a grounded bulkhead is disposed between the circuit breaker and the disconnector , and an output terminal of the circuit breaker and an input terminal of the disconnector are connected by a conductive cable .

According to the present invention, a grounded bulkhead is placed between the circuit breaker and the disconnector, so that only the busbar side is interrupted, and the operation of the circuit breaker can be inspected without interrupting the power supply on the power receiving side or removing the power receiving cable.

Problems, configurations and advantages other than those mentioned above will become clear from the description of the embodiments below.

FIG. 2 is a vertical cross-sectional view of the switchgear of the first embodiment. FIG. 4 is a vertical sectional view of a modified example of the switchgear of the first embodiment. FIG. 11 is a vertical sectional view of a switchgear according to a second embodiment. FIG. 11 is a vertical sectional view of a switchgear according to a third embodiment.

The following describes preferred embodiments of the present invention with reference to the drawings. Note that the following are merely examples of the present invention, and the invention is not limited to the specific embodiments described below. The present invention can of course be modified into various forms, including the embodiments described below.

The switchgear of the first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the switch gear 100 of this embodiment is composed of a circuit breaker 21 and a grounding disconnector 22. Although not shown in the figure, the circuit breaker 21 and the grounding disconnector 22 are housed in a metal box.

The circuit breaker 21 comprises an interrupter vacuum valve 1 that houses a pair of electrodes that can be connected and disconnected, an interrupter insulating layer 2 that covers the interrupter vacuum valve 1, an interrupter insulating rod 3 that is connected to the interrupter vacuum valve 2, and an interrupter operating device 4. The interrupter insulating operating rod 3 is connected to the interrupter operating device 4 on the side opposite to the connection with the interrupter vacuum valve 1. The interrupter vacuum valve 1 can be opened and closed by using the interrupter operating device 4 to move the interrupter insulating rod 3 up and down in the figure. The figure shows the interrupter vacuum valve 1 in an open state. The outer surface of the interrupter insulating layer 2 is grounded with conductive paint or the like, making it a safe structure that will not cause an electric shock even if touched.

The earthing disconnector 22 comprises a disconnecting vacuum valve 6 that houses a pair of electrodes that can be connected and disconnected, a disconnecting side insulating layer 7 that covers the disconnecting vacuum valve 6, a disconnecting side insulating rod 8 that is connected to the disconnecting vacuum valve 6, and a disconnecting actuator 9. The disconnecting side insulating rod 8 is connected to the disconnecting actuator 9 on the opposite side of the connection with the disconnecting vacuum valve 6. The disconnecting vacuum valve 6 can be opened and closed by moving the disconnecting side insulating rod 8 up and down in the figure using the disconnecting actuator 9. The figure shows the disconnecting vacuum valve 6 in an open state. The outer surface of the disconnecting side insulating layer 7 is grounded with conductive paint or the like, making it a safe structure that will not cause an electric shock even if touched.

The embedded conductor 30 in the disconnecting side insulation layer 7 is split into two, one connected to a terminal in the power receiving side bushing 41 and the other connected to a terminal in the grounding bushing 10. The grounding bushing 10 has a grounding terminal 32 on the inside and is normally covered with a lid 11 made of an insulating material. The outer surface of the lid 11 is grounded with conductive paint or the like, making it a safe structure that will not cause electric shock even if touched. When the power receiving side is to be grounded in the event of an accident or during inspection, the lid 11 can be removed and the grounding terminal 32 can be connected to a ground rod or the like for grounding.

A terminal in the output bushing 17 of the circuit breaker 21 and a terminal in the input bushing 18 of the earthing disconnector 22 are connected by a cable 5. The earthing bulkhead 12, which is a characteristic feature of the present invention, is disposed between the circuit breaker 21 and the disconnector 22. The earthing bulkhead 21 is made of metal or resin with a conductive paint, for example, a metal paste, applied to its surface, and is grounded. The earthing bulkhead 21 may be connected to a metal box and grounded. In the figure, the earthing bulkhead 12 is disposed on the disconnector side, but it may also be disposed on the circuit breaker side. Two earthing bulkheads 21 may also be disposed on the disconnector side and the circuit breaker side. The earthing bulkhead 12 is provided at least in a range facing the earthing disconnector 22. The circuit breaker 21 is isolated from the earthing disconnector 22 by the earthing bulkhead 12, so that the hand cannot approach the earthing disconnector 22. Therefore, when inspecting the operation of the vacuum valve 1 for interruption, the work can be safely performed even if the power receiving bushing 41 is in a live state without removing the power receiving side cable. In addition, the outside of the interrupter side insulating layer 2 and the disconnector side insulating layer 7 are grounded, so the distance to the grounded bulkhead 12 can be reduced, resulting in a compact configuration.

Figure 2 shows a modified version of the switchgear of the first embodiment. In this modified version, the grounding bulkhead 12 is provided to surround the grounding disconnector 22, which can reliably prevent electric shock to workers.

According to this embodiment, in the switchgear, the circuit breaker and the disconnector are constructed separately and connected by a cable, and a grounding bulkhead is provided between the circuit breaker and the disconnector. This allows the circuit breaker to be inspected without causing a power outage on the disconnector side or removing the power receiving cable, thereby shortening the work time.

Figure 3 shows a vertical cross-sectional view of a switchgear according to a second embodiment of the present invention. Note that explanations of parts that overlap with the first embodiment will be omitted here.

In the switchgear shown in Figure 1, when grounding the earthing disconnector 22 on the power receiving side, it is necessary to manually remove the cover 11 and connect a grounding rod or the like. With this switchgear, the earthing disconnector 22 can be made small, but it cannot be operated remotely.

As a countermeasure, in the switchgear of this embodiment, as shown in FIG. 3, a grounding device 13 is placed next to the disconnector vacuum valve 6. The grounding device 13 of this embodiment has a movable conductor 16 that is connected to and separated from the grounding device fixed electrode 34 connected to the fixed conductor of the disconnector vacuum valve 6. The movable conductor 16 of the grounding device 13 is connected to the grounding operation device 14, and the movable conductor 16 can be moved up and down by the grounding operation device 14 to perform grounding or opening operations. FIG. 3 shows the grounded state. The flange 15 that contacts the movable conductor 16 is grounded, and the power receiving side of the earth disconnector 22 can be grounded by bringing the movable conductor 16 into contact with the grounding device fixed electrode 34 connected to the fixed conductor of the disconnector vacuum valve 6. Note that in the figure, the grounding device 13 is placed next to the disconnector vacuum valve 6, but there is no specification for the placement of the grounding device 13, and it may be placed below the disconnector vacuum valve 6.

In this embodiment, in addition to the effects of the first embodiment, the grounding device is configured with a movable conductor that is operated by a grounding operation device, so that grounding operations can be performed remotely rather than manually.

Figure 4 shows a vertical cross-sectional view of a switchgear according to a third embodiment of the present invention. Note that explanations of parts that overlap with those of the first and second embodiments will be omitted here.

The earth disconnector 22 in Examples 1 and 2 uses a disconnecting vacuum valve 6, but in this embodiment, instead of the vacuum valve 6, a disconnecting movable conductor operated by a disconnecting operating device is used.

In the figure, the movable disconnecting conductor 43 moves up and down to come into contact with and separate from the disconnector fixed electrode 44 connected to the buried conductor 30 on the power receiving side. The movable disconnecting conductor 43 is connected to the disconnector operating device 9 via the disconnector-side insulating rod 8, and the disconnector operating device 9 can move the movable disconnecting conductor 43 up and down to energize or open the disconnector. Figure 4 shows the state in which the movable disconnecting conductor 43 comes into contact with the disconnector fixed electrode 44 and is energized. The movable disconnecting conductor 43 comes into contact with a conductor connected to a terminal in the disconnector input bushing, and the disconnector can be switched between energized and cut off by moving the movable disconnecting conductor 43 into and out of contact with the disconnector fixed electrode 44.

In this embodiment, in addition to the effects of the first and second embodiments, a movable disconnecting conductor is used as the disconnecting switch instead of a vacuum valve, so the configuration of the earth disconnecting switch can be simplified.

In addition, in the second and third embodiments, the grounding bulkhead 12 may be arranged to surround the grounding disconnector 22, as in the modified example shown in FIG. 2.

1 Breaking vacuum valve 2 Breaking side insulating layer 3 Breaking side insulating rod 4 Breaking operation device 5 Cable 6 Disconnecting vacuum valve 7 Disconnecting side insulating layer 8 Disconnecting side insulating rod 9 Disconnecting operation device 10 Grounding bushing 11 Cover (insulator)
12 Earthing bulkhead 13 Earthing device 14 Earthing device operating device 15 Flange 16 Movable conductor 17 Circuit breaker output side bushing 18 Disconnector input side bushing 21 Circuit breaker 22 Earthing disconnector 30 Buried conductor 32 Earthing terminal 34 Earthing device fixed electrode 41 Receiving side bushing 42 Busbar side bushing 43 Disconnecting movable conductor 44 Disconnector fixed electrode 100 Switchgear

Claims (11)

In switchgear that houses a circuit breaker and a disconnector in a box,
A grounded bulkhead is disposed between the circuit breaker and the disconnector;
The switchgear is characterized in that an output terminal of the circuit breaker and an input terminal of the disconnector are connected by a conductive cable. In switchgear that houses a circuit breaker and a disconnector in a box,
A grounded bulkhead is disposed between the circuit breaker and the disconnector;
The disconnector includes a grounding device;
The switchgear is characterized in that the grounding device is composed of a grounding terminal connected to an electrode of a disconnector and an insulating cover covering the grounding terminal. The switchgear according to claim 1 or 2 ,
The switchgear is characterized in that the grounding partition is made of metal or resin and has a conductive paint applied to its surface. The switchgear according to claim 2 ,
The switchgear is characterized in that an output terminal of the circuit breaker and an input terminal of the disconnector are connected by a conductive cable. The switchgear according to claim 1 or 2 ,
The switchgear, wherein the grounding bulkhead is connected to a metal box. The switchgear according to claim 1 or 2 ,
The switchgear, wherein the grounding partition is arranged to surround the disconnector. The switchgear according to claim 1 or 2 ,
The circuit breaker and the disconnector are covered with an insulator, and an outer surface of the insulator is grounded. The switchgear according to claim 1,
The switchgear is characterized in that the disconnector comprises a grounding device. The switchgear according to claim 8 ,
the grounding device is characterized in that it comprises a fixed electrode for grounding connected to an electrode of the disconnector, and a movable electrode for grounding that is movable by an operating device and moves in contact with and away from the fixed electrode for grounding. The switchgear according to claim 1 or 2 ,
The switchgear, wherein the disconnector comprises a vacuum valve for disconnection. The switchgear according to claim 1 or 2 ,
The switchgear is characterized in that the disconnector is composed of a fixed electrode for disconnection and a movable electrode for disconnection that is brought into contact with and separated from the fixed electrode for disconnection and moved by an operating device.

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