JP2586240B2 - Gas insulated switchgear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear applied to an electric power system, and more particularly to a shutoff unit thereof.

[0002]

2. Description of the Related Art FIG.
It is sectional drawing which shows the interrupting | blocking unit part of the conventional gas insulated switchgear similar to what was shown by patent document 4. In the figure, reference numeral 1 denotes a tank containing a shutoff unit, 2 denotes a connection tank adjacent to the tank 1 and containing a drawer of the shutoff unit, 3
Is a connecting conductor that is conductively connected to the interrupting unit to draw out, and 4 is an insulating spacer that insulates and supports the connecting conductor 3. One of the conical shapes is a convex surface, and the other is a concave surface. Reference numeral 5 denotes a central conductor integrally cast with the insulating spacer 4, and reference numeral 11 denotes a fixed electrode of the cutoff unit for electrically connecting the connection conductor 3. 11a is a fixed electrode 11
A fixed contact 11b, an opening provided in the fixed electrode 11, an insulating support 12 for insulatingly supporting the fixed electrode 11, a cylinder 13 containing an insulating gas, and a piston 14 fitted in the cylinder 13. Reference numeral 15 denotes a movable contact that forms a movable electrode fixed to the piston 14, and reference numeral 16 denotes a nozzle that forms the movable electrode. The inside of the tank 1 and the connection tank 2 is filled with an insulating gas of a predetermined pressure, and the power-applied portions such as the cylinder 13, fixed electrode 11, connection conductor 3, and center conductor 5 are ground potential tank 1 and the connection tank 2 Insulated from The arc-extinguishing chamber of the shut-off unit includes a fixed electrode 11, an insulating support portion 12, a movable contact 15, a nozzle 16, and the like.

Next, the operation will be described. First, in the closed state of the shut-off unit, the movable contact 15 and the fixed contact 11a are in fitting contact with each other, and the movable contact 15, the fixed contact 11a, the fixed electrode 11, the connection conductor 3, the center conductor 5 and the like are energized. I have.
When the piston 14 moves to the left in the drawing by the tripping command, the movable contact 15 is separated from the fixed contact 11a, an arc is generated during that time, and the insulating gas in the cylinder 13 is compressed, and the hollow portion of the piston 14 is compressed. Then, it is ejected from the nozzle 16 through the inside and outside of the movable contact 15. This insulating gas is blown against the arc generated between the movable contact 15 and the fixed contact 11a to extinguish the arc and cut off the current. However, the insulating gas blown to the arc is ionized, and the movable contact 15 and the fixed Contact
It becomes a hot gas containing the metal element 11a, and the fixed electrode 11a
Flows in parallel with the connection conductor 3 from the opening 11b, and cools and combines with the conical insulating spacer 4 with the passage of time to become an insulating gas again (the flow of the hot gas is shown by a broken line in FIG. 3).

[0004]

The conventional gas insulated switchgear is constructed as described above, and the hot gas is blown onto the surface of the insulating spacer 4. Therefore, when the hot gas is not sufficiently cooled and is still in an ionized state. The creepage dielectric strength of the insulating spacer 4 is remarkably reduced, and a conductive metal compound is adhered to the vicinity of the concave center conductor 5 of the insulating spacer 4, so that the creepage dielectric strength of the insulating spacer 4 is also reduced. To avoid this, the distance between the fixed electrode 11 and the insulating spacer 4 must be increased, and there is a technical problem to be solved that it is difficult to downsize the gas insulated switchgear.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a gas insulated switchgear which can be downsized without lowering the creeping dielectric strength of the insulating spacer. I do.

[0006]

A gas insulated switchgear according to the present invention has a cylindrical tank accommodating a shut-off unit, one end of which has a convex surface and the other end having a concave insulating spacer fixed to both end surfaces thereof, and seals the shut-off unit with the tank. With an insulating unit that is electrically insulated from the tank and is filled with an electrically insulating medium and an insulating gas of the arc-extinguishing medium in the tank, and extinguishes the hot gas generated when the arc is extinguished in the arc-extinguishing chamber of the interrupting unit. The chamber is discharged in a conical shape, and an insulating spacer is placed with a convex surface facing a position within the range of the conical surface.

[0007]

According to the present invention, hot gas generated during arc extinguishing in the arc extinguishing chamber of the shut-off unit is discharged from the arc extinguishing chamber into a conical surface, and the convex surface is directed to a position within the conical surface. Since the insulating spacer is placed, no hot gas is sprayed on the surface of the insulating spacer, and no conductive metal compound adheres.

[0008]

【Example】

Embodiment 1 FIG. FIG. 1 is a sectional view showing a main part of an embodiment of the present invention, and FIG. 2 is a plan view showing a fixed electrode of FIG. In FIG. 1, 1, 3, 4, 5, 12, 15, and 16 are the same as those in the above-mentioned conventional gas insulated switchgear. Reference numeral 21 denotes a fixed electrode of the cutoff unit, which electrically connects the connection conductor 3. twenty one
Reference symbol a denotes a cylindrical fixed contact constituting the fixed electrode 21, the base of which is conical. 21b is a fixed electrode
An opening formed in the fixed contact 21 has a conical surface following the surface of the base of the fixed contact 21a.

In this embodiment, the arc-extinguishing chamber of the shut-off unit comprises a fixed electrode 21, an insulating support 12, a movable contact 15, a nozzle
16 and the like, and although not shown, FIG.
Similarly to the above, a cylinder 13 and a piston 14 are provided.

In this embodiment, the movable contact 15 and the fixed contact 21a make a fitting contact with each other when the shut-off unit is turned on, and the movable contact 15, the fixed contact 21a, the fixed electrode 21, the connection conductor 5 and the like are energized. ing. Fig. 3
Moving to the left in the same way as above, the movable contact 15 becomes a fixed contact
An arc is generated during the separation from the nozzle 21a, and the insulating gas in the cylinder 13 is compressed while being discharged from the nozzle 16 through the hollow portion of the piston 14 and the inside and outside of the movable contact 15. The insulating gas blown to the arc generated between the movable contact 15 and the fixed contact 21a is ionized and becomes a hot gas containing the metal element of the movable contact 15 and the fixed contact 21a. It flows along the surface and the conical surface of the inner surface of the opening 21b, is discharged into the tank 1 from the opening 21b, and cools and combines with the end surface of the tank 1 over time to become an insulating gas again (see FIG. 1). The flow of the hot gas is indicated by broken lines). Since the insulating spacer 4 is placed so that its convex surface faces a position within a conical surface extending from the surface of the base of the fixed contact 21a and the inner surface of the opening 21b, hot gas is applied to the surface of the insulating spacer 4. There is no spraying, and no conductive metal compound adheres. Therefore, it is possible to reduce the size without reducing the creeping dielectric strength of the insulating spacer 4.

[0011]

As described above, according to the present invention, hot gas generated in the arc-extinguishing chamber of the shut-off unit is discharged from the arc-extinguishing chamber into a conical surface, and a convex surface is formed at a position within the conical surface. Since the insulating spacer is placed in the direction, the hot gas is not sprayed on the surface of the insulating spacer, and the conductive metal compound does not adhere to the insulating spacer, so that the creepage insulation strength is not reduced. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a plan view showing the fixed electrode of FIG.

FIG. 3 is a sectional view showing a shut-off unit of a conventional gas insulated switchgear.

[Description of Signs] 1 Tank 3 Connecting conductor 4 Insulating spacer 5 Center conductor 12 Insulating support 15 Movable contact 16 Nozzle 21 Fixed electrode 21a Fixed contact 21b opening

Claims (1)

(57) [Claims] 1. A cylindrical tank accommodating a shut-off unit, one end of which has a convex surface and the other end of which has a concave insulating spacer fixed thereto and hermetically sealed, and the insulating unit is insulated from the tank and electrically insulated in the tank. In a gas insulated switchgear having a shut-off unit portion filled with a medium and an insulating gas of an arc-extinguishing medium, a high-temperature decomposition gas (hereinafter, referred to as a hot gas) generated when an arc is extinguished in an arc-extinguishing chamber of the shut-off unit. From the arc-extinguishing chamber in the form of a conical surface, and the insulating spacer is placed with the convex surface facing a position within the range of the conical surface.