JPH04121315U - gas insulated switchgear - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the size of the grounding circuit of gas-insulated switchgear and improve safety. [Structure] This is a gas-insulated switchgear in which the components of a switching circuit including an earthing switch ES are housed in a container 1 filled with insulating gas. A discharge gap was formed by opposing a discharge electrode 25 to a portion 22 of a conductor that was arranged in an insulating gas atmosphere and forming a ground circuit of the earth switch ES. When a high frequency surge occurs when the earthing switch is turned on, a discharge is generated in the discharge gap to prevent discharge from occurring in a portion of the grounding circuit located outside the container 1.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a gas insulated switchgear.

0002

[Conventional technology]

Gas-insulated switchgear has a structure in which switching equipment such as circuit breakers, disconnectors, and earthing switches are housed in a container filled with insulating gas such as SF ₆ gas. The grounding side terminal of the earthing switch is connected to an external grounding terminal attached to the container via a predetermined grounding conductor, and the external terminal for grounding is connected to a ground potential section via a grounding wire.

0003

[Problem that the idea aims to solve]

In conventional gas-insulated switchgear, when the earthing switch is turned on, the power cable is Electric charge in the main circuit inside the load or gas-insulated switchgear container is discharged, generating a high-frequency surge. However, discharge may occur in the part of the earthing circuit of the earthing switch located outside the enclosure. It was dangerous. In addition, in conventional gas-insulated switchgear, the grounding circuit of the grounding switch is forced to Since there was no part that would cause a discharge, it was difficult to identify the location where the discharge occurred. I couldn't do it. Therefore, in order to improve the insulation performance of the grounding circuit, discharge is generated. Insulation distances must be large at all points where contact may occur, and A large insulator is required to insulate the ground circuit, which increases the size of the equipment and There was a problem of high cost.

0004 The purpose of this invention is to improve safety by eliminating the risk of electrical discharge occurring outside the container. In addition, the area around the grounding circuit of the grounding switch can be made smaller and costs can be reduced. An object of the present invention is to provide a gas insulated switchgear.

[0005]

[Means to solve the problem]

This invention consists of the components of a switching circuit that includes an earthing switch in a container filled with insulating gas. This device is related to gas-insulated switchgear that houses a grounding element. The discharge end is connected to the part of the conductor that constitutes the grounding circuit of the enclosure, which is placed in an insulating gas atmosphere. A discharge gap was formed by facing each other.

[0006]

[Effect]

The gas pressure and humidity in the above discharge gap are strictly controlled, and the environment is stable. Since the process is carried out in an insulating gas, the gap can be adjusted in advance to increase the When a frequency surge occurs, a discharge can always be generated in the discharge gap. Ru. Therefore, discharge may occur at unspecified points in the part of the grounding circuit located outside the container. This prevents equipment damage and improves safety. be able to. In addition, since it is possible to identify the location where discharge occurs due to high frequency surge, other The earthing circuit of the earthing switch is designed to reduce the insulation distance and downsize the insulation material. The surroundings can be made smaller and costs can be reduced.

[0007]

【Example】

Figure 1 shows the main parts of an embodiment of the present invention, in which 1 is a metal container. , 2 is a bottom plate that tightly closes the bottom of the container 1. Hand hole on the side of container 1 1a and 1b are provided, and the hand hole 1a is closed by a cover plate 3. Also The hand hole 1b is closed by a cover plate 4, and inside the cover plate 4 there is a A container 5 containing an adsorbent for adsorbing gas and moisture is attached.

[0008] A frame 6 is fixed inside the container, and an insulating support 7 is connected to the frame. Fixing the fixed contact 9 of the disconnector DS and the earthing switch ES to the conductor 8 supported by the A contact 10 is attached. The movable contact 11 of the disconnector DS is Connected to a conductor that connects to other switching equipment such as a disconnector. Also, the earthing switch ES The movable contact 12 is attached to the frame 6 in an insulated state via an insulator 13. I'm being kicked. Container 1 houses equipment for three phases, including a three-phase disconnector DS and a connection. The ground switches ES are arranged side by side in a direction perpendicular to the plane of the drawing. 3-phase earthing switching The contacts 14 of the movable contacts 12 of the device ES are connected by an insulating connecting member 15. , are operated by a common operating mechanism 16.

[0009] The movable contacts 12 of the earthing switches for each phase extend vertically within the container 1. It is connected to the upper end of a ground bar 17 provided. Movable controller for 3-phase earthing switch Three ground bars (only two are shown in the figure) 17 connected to the tact It is supported by supports 18 and 19, and the lower ends of the grounding bars 17 of each phase are insulated to the bottom plate 2. A conductor 22 is connected to an external terminal 21 of each phase attached via a bushing 20. It is connected. The external terminal 21 performs various measurements and tests on the gas insulated switchgear. It is often used as a current detection terminal.

0010 In addition, the voltage detection terminal 23 is inserted through the insulating bushing that supports the external terminals of each phase. The voltage detection terminal 23 is connected to the earthing switch of the corresponding phase via an electric wire. connected to a dynamic contact. Connection part between ground bar 17 and movable contact 12 A shield 24 is arranged to shield the vicinity.

[0011] During steady operation of the gas insulated switchgear, the external terminal 21 is connected via a grounding wire (not shown). connected to ground potential. Grounding bar 17, conductor 22, external terminal 21, and the external end The grounding circuit of the grounding switch ES is configured by the grounding wire (not shown) connected to the terminal. Ru.

0012 In this embodiment, a discharge electrode 25 is attached to the lower inner surface of the container 1. this As shown in FIG. 2, the discharge electrode is connected to a bracket 26 fixed to the inner surface of the container 1. , a bolt 27 screwed into a screw hole provided in the bracket 26, and a bolt 27 A spherical electrode 28 attached to the tip of the spherical electrode 28 and a lock nut engaged with the bolt 27 It consists of 29. A spherical electrode 28 faces a conductor 22 forming part of a grounding circuit. A discharge gap G is formed between the electrode 28 and the conductor 22. discharge The gap G can be set appropriately by adjusting the amount of protrusion of the bolt 27. can. The potential of the discharge electrode 25 is maintained at the same potential as the potential of the container 1.

As shown by the chain line in FIG. 2, the conductor 22 has a flat oval cross-sectional shape, and its narrower curved side faces the discharge electrode 25. . A conductor 8 to which a movable contact of the earthing switch ES is attached is connected via a conductor 31 to a terminal 30 of a cable head CHd attached to the bottom plate 2. A terminal portion 32 of the cable C is connected to the cable head CHd. SF ₆ gas is sealed in the container 1 at a predetermined pressure, and the gas pressure is controlled to be maintained within a certain range.

As described above, if the discharge gap G is provided in an atmosphere of SF ₆ gas in which the pressure is controlled and moisture has been removed by an adsorbent, stable discharge can be caused in the gap. Therefore, if a high-frequency surge occurs when the earthing switch is turned on, sparks can always be thrown in the discharge gap G, and it is possible to eliminate the possibility that electric discharge will occur in the part of the earthing circuit located outside the container 1.

[0015] In the above embodiment, the disconnector and earthing switch of the gas insulated switchgear are installed in the gas Although a discharge gap G is provided in the space, for example, under the bottom plate 2, as shown by the chain line in FIG. A metal auxiliary container 31 is connected to the surface, and a discharge gap G is formed in the auxiliary container 31. may be completed. FIG. 3 shows an example in which a discharge gap G is formed within the auxiliary container 31. Therefore, in this example, the conductor bar 32 connected to the ground bar 17 in Fig. 1 is attached to the bottom plate 2. The insulating bushing 33 is inserted into the auxiliary container 31, and the bottom of the auxiliary container 31 is inserted into the auxiliary container 31. The external terminal 35 attached to the section via the bushing 34 is connected to the conductor via the connecting conductor 36. It is connected to the rod 32. A terminal conductor 37 is provided to penetrate the bushing 33, A voltage detection terminal 38 is provided to penetrate the bushing 34. Voltage detection terminal 38 is connected to a terminal conductor 37 through an electric wire 39, and the terminal conductor 37 is connected to an electric wire (not shown). It is connected via a wire to the movable contact of the earthing switch ES.

A rod-shaped conductor 40 is provided by secretly passing through a boss portion 31a provided on the side wall of the auxiliary container 31, and a spherical electrode 41 is attached to the end of the rod-shaped conductor 40 located inside the auxiliary container. . The spherical electrode 41 is opposed to the connecting conductor 36, and a discharge gap G is formed between the spherical electrode 41 and the connecting conductor 36. A flange 40a is provided at the end of the rod-shaped conductor 40 located outside the auxiliary container, and stud bolts 42, 42 fixed to the boss portion 31a are fitted into through holes provided in the flange 40a. Lock nuts 43 and 44 are engaged with each stud bolt 42, and by adjusting the positions of the lock nuts 43 and 44, the discharge gap G can be adjusted. SF ₆ gas is sealed in the auxiliary container 31 at a predetermined pressure, and this gas pressure is also managed in the same way as the gas pressure in the container 1. Although not shown, an adsorbent for adsorbing decomposed gas and moisture is also provided in the auxiliary container 31.

[0017] In the example shown in FIG. 3, there is a discharge gap G in the auxiliary container 31 isolated from the container 1. is provided, the decomposed gas generated by the discharge in the discharge gap G is transferred to the gas-insulated switch. It is possible to eliminate the risk of affecting the component devices of the device.

[0018] In the above example, the unit where the cable of the gas insulated switchgear is drawn is Although this invention has been applied, it is also possible to apply the invention to other units that have earthing switches. Of course you can.

[0019]

[Effect of the idea]

As described above, according to the present invention, the insulation of the conductor constituting the grounding circuit of the earthing switch is Since a discharge gap is provided in the part placed in the gas atmosphere, the earthing switch cannot be turned on. When a high-frequency surge occurs, the discharge must occur at the discharge gap. I can do it. Therefore, discharge occurs at unspecified points in the part of the grounding circuit located outside the container. This eliminates the possibility of accidental damage, prevents damage to equipment, and improves safety. There are benefits that can be enhanced. In addition, according to the present invention, discharge due to high frequency surge Since it is possible to identify the location where this occurs, it is possible to reduce the insulation distance in other locations and downsize the insulator. With this in mind, it is possible to downsize the area around the grounding circuit of the grounding switch and reduce costs. There are advantages that can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing essential parts of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of section A in FIG. 1;

FIG. 3 is a sectional view showing essential parts of another embodiment of the present invention.

[Explanation of symbols]

1... Container, ES... Earthing switch, 10... Fixed contact of the earthing switch, 12... Movable contact of the earthing switch, 17
...Grounding bar, 21...External terminal, 22...Conductor, G...Discharge gap, 25...Discharge electrode, 28, 41...Spherical electrode.

Claims (1)

[Scope of utility model registration request] 1. In a gas-insulated switchgear in which components of a switching circuit including an earthing switch are housed in a container filled with an insulating gas, an insulating gas atmosphere of a conductor constituting the earthing circuit of the earthing switch is provided. A gas insulated switchgear characterized in that a discharge gap is formed by opposing discharge terminals in a portion disposed therein.