JPH11103520A - Gas-insulated switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-insulated switchgear, capable of surely capturing foreign matters which float in a gas space and move, without depending on the diameter of metallic foreign matter capturing holes, and having a more superior insulation performance. SOLUTION: In a gas-insulated switchgear provided with a high-voltage conductor 1, a tank wall 2 in which an insulating gas is put and sealed, metallic foreign matter capturing holes 3 provided in the bottom part of the tank wall 2 to capture metallic foreign matters, and covers 4 having holes 4 for covering the upper parts of the metallic foreign matter capturing holes 3, holes in each cover 4 are distributed so that an electric field strength in a space 5 above the cover 4 having holes may be larger, the nearer it is to the center of the metallic foreign matter capturing hole 3.

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 (GIS), and more particularly to a gas insulated switchgear (GIS) having an improved insulating performance by facilitating removal of foreign substances present in a tank.

[0002]

2. Description of the Related Art When a metal foreign matter enters a GIS, the metal foreign matter is charged and floats, and adheres to a spacer or collides with a high-voltage conductor, causing local electric field concentration to cause insulation breakdown. For this reason, the GIS is designed to minimize the intrusion of metal foreign matter and to take into account the case where metal foreign matter is mixed in. When metal foreign matter is mixed in, the foreign matter floats when the surface electric field of the tank becomes larger than the floating electric field of the foreign matter.

A first prior art for preventing the floating of foreign matter is disclosed in Japanese Patent Publication No. 50-40702, in which a suppression grid having the same potential as the tank is provided along the circumferential direction of the tank bottom. A method is described in which the electric field at the bottom of the tank is reduced to suppress the floating of the foreign matter when the foreign matter enters below the suppression grid.

[0004] A second prior art is disclosed in
Japanese Patent Application Laid-Open No. 136649 describes a method of providing a metal foreign matter capturing hole at the bottom of a tank and further covering the hole with a perforated cover.

[0005]

However, in the first prior art, there is a possibility that the foreign matter which has floated and moved in the gas space may jump over the restraint grid, or the foreign matter may re-emerge due to the vibration of the opening / closing operation in the opening / closing section. There was a disadvantage.

In the second prior art, the curved shape of the perforated cover is uniquely determined by the diameter of the metal foreign matter capturing hole.
The electric field distribution on the perforated cover surface cannot be controlled. Therefore, when the diameter of the metal foreign matter capturing hole is small, there is almost no effect of drawing in the foreign matter through the perforated cover, and there is a disadvantage that the foreign matter that has floated and moved in the gas space jumps over the perforated cover and cannot be reliably captured. Was.

An object of the present invention is to provide a gas insulated switchgear capable of reliably capturing foreign matter that floats and moves in a gas space without depending on the size of a metal foreign matter capture hole and improving insulation performance. Is to do.

[0008]

To achieve the above object, a first aspect of the present invention is to provide a high-voltage conductor, a container surrounding the high-voltage conductor and enclosing an insulating gas, and a projection protruding downward at the bottom of the container. A gas insulated switchgear provided with a metal foreign matter capturing hole provided for capturing the metal foreign matter and a conductive cover having a hole through which the metal foreign matter can pass and covering an upper portion of the metal foreign matter capturing hole. The holes provided in the conductive cover are distributed such that the electric field strength in the space above the conductive cover becomes closer to the center of the metal foreign matter capturing hole.

According to a second aspect of the present invention, there is provided a high-voltage conductor, a container surrounding the high-voltage conductor and enclosing an insulating gas, and a metal foreign matter capturing hole provided at the bottom of the container and projecting downward to capture metal foreign matter. And a gas-insulated switchgear provided with a mesh-shaped conductive cover that covers the upper part of the metal foreign matter capturing hole, the equivalent diameter of a wire constituting the conductive cover becomes smaller as it is closer to the center of the metal foreign matter capturing hole. The configuration is as follows.

According to a third aspect of the present invention, there is provided a high-voltage conductor, a container surrounding the high-voltage conductor and enclosing an insulating gas, and a metal foreign matter capturing hole provided at the bottom of the container and projecting downward to capture metal foreign matter. And a conductive cover having a hole through which the metallic foreign matter can pass and covering an upper portion of the metallic foreign matter capturing hole, wherein the electric field strength in the space above the conductive cover is such that the metallic foreign matter capture The conductive cover is formed in a curved shape protruding upward such that the conductive cover becomes larger as it is closer to the center of the hole.

According to a fourth aspect of the present invention, in the first or second aspect, a plurality of conductive cylindrical members are provided concentrically in the metal foreign matter capturing hole in place of the conductive cover, and the plurality of conductive cylinders are provided. It is configured such that the radial interval between the conductive cylindrical members becomes closer to the center of the metal foreign matter capturing hole.

In a fifth aspect based on the first or second aspect, a plurality of ring-shaped conductors are provided concentrically above the metal foreign matter capturing hole in place of the conductive cover. The ring-shaped conductor is configured such that the radial distance between the ring-shaped conductors increases as the distance from the center of the metal foreign matter capturing hole increases.

According to the first to fifth aspects of the present invention, it is possible to utilize the action of the lines of electric force that gather toward the center of the metal foreign matter capturing hole without depending on the size of the metal foreign matter capturing hole. Metallic foreign matter mixed in the switchgear can be reliably captured in the metallic foreign matter capturing hole, and the insulation performance of the gas insulated switchgear can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a gas edge opening / closing device (GIS) according to the present invention will be described with reference to FIGS. FIG. 1 is a partially cutaway view of the first embodiment. This GIS
Are a high-voltage conductor 1 to which a high voltage is applied, a stator electrode 33 for interrupting a current flowing through the high-voltage conductor 1, a movable electrode 32, an electrode driving mechanism 31 for driving the movable electrode 32, and an insulating gas. 5, a tank wall 2, which is grounded and enclosed, a metallic foreign matter capturing hole 3 provided at the bottom of the tank wall 2, a perforated cover 4 for covering the metallic foreign matter capturing hole 3, and the like.

The detailed structure of the metal foreign matter capturing hole shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a view taken along the line AA in FIG. 1,
FIG. 3 is a sectional view taken along line BB of FIG. However, in FIG. 2, the stator electrode 33 and the mover electrode 32 are omitted for simplicity. FIG. 3 also shows a typical shape of the electric lines of force 6 in the space 5 on the perforated cover 4, a metal foreign matter 7 having moved into the space 5 from the left side, and a locus 8 thereof.

The metal foreign matter capturing hole 3 has a cylindrical structure protruding downward from the bottom of the tank wall 2. The perforated cover 4 is a conductive cover that is electrically connected to the tank wall 2, has a curved shape that matches the inner surface of the tank wall 2, and has a hole through which metal foreign matter can pass. More specifically, the mesh cover has an equivalent mesh diameter of more than 0.25 mm.

In this embodiment, the structure of the perforated cover 4 for changing the shape of the lines of electric force 6 as shown in FIG. 3 will be described below.
The ratio of the area occupied by the structural material (wire) of the perforated cover 4 on the curved surface of the perforated cover 4 is defined as the space factor. Conversely, the ratio of the area occupied by the space (hole) on the curved surface of the perforated cover 4 is the porosity. In order to investigate the effect of the space factor, as a simple model, a parallel plate electrode consisting of an anode to which a voltage is applied and a ground electrode is assumed. By changing the space factor of the cover (net-like cover) or the equivalent diameter of the wire constituting the perforated cover, the electric field intensity on the perforated cover surface was obtained by numerical calculation.

FIG. 4 shows the relationship between the space factor of the perforated cover and the electric field intensity on the surface of the perforated cover at an equivalent wire diameter of 2 mm. FIG. FIG. 5 shows the results obtained by determining the relationship between the electric field strength and the electric field strength of the perforated cover surface. From FIG. 4, when the equivalent diameter of the wire is constant and the space factor of the perforated cover is reduced, the electric field intensity on the surface of the perforated cover increases. In other words, when the equivalent diameter of the wire is constant and the porosity of the perforated cover is increased, the electric field intensity on the surface of the perforated cover increases. In addition, from FIG. 5, when the equivalent diameter of the wire is reduced while the space factor of the perforated cover is constant (the porosity is constant), the electric field intensity on the surface of the perforated cover increases.

From the results shown in FIGS. 4 and 5, it is understood that the electric field intensity on the surface of the perforated cover can be changed by changing (distributing) the space factor or the equivalent diameter of the wire in the perforated cover depending on the location. Therefore, as shown in FIG. 3, the space factor of the perforated cover 4 is reduced as the wire diameter is constant and closer to the center of the metallic foreign matter capturing hole 3 (the porosity of the porous cover 4 is reduced as the metallic foreign matter is captured). By increasing the closer to the center of the hole 3, the electric field strength on the surface of the perforated cover 4 can be increased closer to the center of the metal foreign matter capturing hole 3. As a result, the lines of electric force 6 in the space 5 on the perforated cover 4 have a shape converging toward the center of the metal foreign matter capturing hole 3. 3 can be reliably guided and captured.

Next, a second embodiment of the GIS according to the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view perpendicular to the axial direction of the high-voltage conductor 1 of the second embodiment, and FIG.
It is B sectional drawing. FIG. 6 also shows the stator electrode 3 for simplicity.
3 and the mover electrode 32 are omitted. This embodiment is the first
The difference from the embodiment is the shape of the perforated cover 4. The other configuration is the same as that of the first embodiment, and the description is omitted here.

The perforated cover 4 of the present embodiment has an upwardly convex curved surface protruding toward the high-voltage conductor 1. By adopting such a shape, the electric field strength on the surface of the perforated cover 4 can be increased closer to the center of the metal foreign matter capturing hole 3 without changing the space factor of the perforated cover or the equivalent diameter of the wire.

Therefore, in the present embodiment, similarly to the first embodiment, the lines of electric force (not shown) in the space 5 above the perforated cover 4 have a shape gathering toward the center of the metal foreign matter capturing hole 3. Therefore, the metallic foreign matter that has moved to the space 5 can be reliably guided and captured in the metallic foreign matter capturing hole 3. Further, in the case of this embodiment, the electric field strength on the surface of the tank wall 2 is reduced by the perforated cover 4.
, The height of the metal foreign matter that has moved can be suppressed.

Next, a third embodiment of the GIS according to the present invention will be described with reference to FIG. FIG. 8 shows a high-voltage conductor 1 according to the third embodiment.
FIG. 4 is a transverse sectional view perpendicular to the axial direction of FIG. 8, the stator electrode 33 and the mover electrode 32 are omitted for simplicity. This embodiment is different from the first embodiment in that the perforated cover 4
And the distance between the wires is reduced as the distance from the center of the metal foreign matter capturing hole 3 is reduced, and the perforated cover 4 is reduced.
Is that the space factor is almost constant. The other configuration is the same as that of the first embodiment, and the description is omitted here.

By configuring the perforated cover 4 in this manner, the electric field strength on the surface of the perforated cover 4 can be reduced by the metal foreign matter capturing hole 3.
The closer to the center, the larger it can be. Therefore, similarly to the first embodiment, the lines of electric force (not shown) in the space 5 on the perforated cover 4 have a shape converging toward the center of the metal foreign matter capturing hole 3 and move to the space 5. The trapped metal foreign matter can be reliably guided to and trapped in the metal foreign matter capturing hole 3. Further, in the case of the present embodiment, the holes of the perforated cover 4 increase from the center of the metal foreign matter capturing hole 3 toward the peripheral portion, and accordingly,
It is also possible to improve the capture rate of metal foreign matter.

Next, a fourth embodiment of the GIS according to the present invention will be described with reference to FIG. FIG. 9 shows the high-voltage conductor 1 of the fourth embodiment.
FIG. 4 is a transverse sectional view perpendicular to the axial direction of FIG. Also in FIG. 9, the stator electrode 33 and the mover electrode 32 are omitted for simplicity. This embodiment is different from the second embodiment shown in FIG.
The larger the distance is, the larger the distance between the wires is, and the wider the distance between the wires is, the closer to the center of the metallic foreign matter capturing hole 3, and the space factor of the perforated cover 4 is almost constant. The other configuration is the same as that of the second embodiment, and the description is omitted here.

In the present embodiment, as in the second embodiment, the metallic foreign matter that has moved into the space 5 can be reliably guided to the metallic foreign matter capturing hole 3 and captured. Furthermore, in the case of the present embodiment, the maximum electric field strength in the space 5 can be made lower than that of the second embodiment by increasing the equivalent diameter of the wire closer to the center of the metal foreign matter capturing hole 3, so that the insulation limit of the electric field strength is reduced. Can be improved compared to the second embodiment.

Next, a fifth embodiment of the GIS according to the present invention will be described with reference to FIG. FIG. 10 is a detailed view of the metal foreign matter capturing hole 3 of the fifth embodiment. In this embodiment, instead of the perforated cover 4, a plurality of conductive cylinders 14 having the same thickness are provided concentrically in the metal foreign matter capturing hole 3. The other configuration is the same as that of the first embodiment, and the description is omitted here.

In this embodiment, the space in the hole cover is closer to the center of the metal foreign matter capturing hole 3 by increasing the radial spacing of the conductive cylinder 14 closer to the center of the metal foreign matter capturing hole 3. This is equivalent to a smaller configuration. That is,
The electric field strength in the space above the conductive cylinder 14 is
It is configured to be larger as it is closer to the center.

Therefore, also in this embodiment, similarly to the first embodiment, the metallic foreign matter that has moved into the space above the conductive cylinder 14 can be reliably guided to the metallic foreign matter capturing hole 3 and captured. Furthermore,
In the case of this embodiment, since the electric field intensity inside the metal foreign matter capturing hole 3 partitioned by the conductive cylinder 14 is very small, it is possible to prevent the metal foreign matter captured in the metal foreign matter capturing hole 3 from re-emerging.

Next, a sixth embodiment of the GIS according to the present invention will be described with reference to FIG. FIG. 11 is a detailed view of the metal foreign matter capturing hole 3 of the sixth embodiment. In this embodiment, instead of the perforated cover 4, a plurality of ring-shaped conductors 16 are provided concentrically above the metal foreign matter capturing holes 3. The diameter of the cross section perpendicular to the circumferential direction of each ring-shaped conductor is equal. Other configurations are first
The description is omitted here because it is the same as the embodiment. The ring-shaped conductor 16 is supported by a support member 17 that is a conductor,
The ring-shaped conductor 16 has durability against electromagnetic force generated.

In this embodiment, the space between the ring-shaped conductors 16 in the radial direction is increased as the distance from the center of the metal foreign matter capturing hole 3 increases. This is equivalent to a smaller configuration. In other words, the configuration is such that the electric field strength in the space above the ring-shaped conductor 16 increases as it approaches the center of the metal foreign matter capturing hole 3.

Therefore, also in the present embodiment, similarly to the first embodiment, the metallic foreign matter that has moved into the space above the ring-shaped conductor 16 can be reliably guided to the metallic foreign matter capturing hole 3 and captured. Further, in the case of the present embodiment, the net-shaped perforated cover 4 of the first embodiment is used.
Instead of using the concentric ring-shaped conductor 16, the holes are larger than those of the perforated cover 4, so that the capture rate of metal foreign substances can be improved accordingly. Further, an insulating paint for suppressing the floating of metal foreign matter can be uniformly applied.

[0033]

According to the present invention, the action of the lines of electric force gathering toward the center of the metal foreign matter capturing hole can be utilized without depending on the diameter of the metal foreign matter capturing hole. The metal foreign matter mixed in the metal foreign matter can be reliably captured in the metal foreign matter capturing hole, and the insulation performance of the gas insulated switchgear can be improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view of a first embodiment of a gas edge opening / closing device according to the present invention.

FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a diagram showing the relationship between the space factor of the perforated cover and the electric field intensity on the surface of the perforated cover.

FIG. 5 is a diagram showing a relationship between an equivalent diameter of a wire and an electric field intensity on a surface of a perforated cover.

FIG. 6 is a cross-sectional view of a second embodiment of the gas edge opening / closing device according to the present invention.

FIG. 7 is a sectional view taken along line BB of FIG. 6;

FIG. 8 is a cross-sectional view of a third embodiment of the gas edge opening / closing device according to the present invention.

FIG. 9 is a cross-sectional view of a fourth embodiment of the gas edge opening / closing device according to the present invention.

FIG. 10 is a detailed view of a metal foreign matter capturing hole of a fifth embodiment of the gas edge opening and closing device according to the present invention.

FIG. 11 is a detailed view of a metal foreign matter capturing hole of a sixth embodiment of the gas edge opening and closing device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... High voltage conductor, 2 ... Tank wall, 3 ... Metal foreign matter capture hole, 4
... perforated cover, 5 ... space, 6 ... lines of electric force, 7 ... metallic foreign matter, 8 ... locus of metallic foreign matter, 14 ... conductive cylinder, 16 ... ring-shaped conductor, 31 ... electrode drive mechanism, 32 ... mover electrode ,
33 ... stator electrode.

Continued on the front page (72) Inventor Manabu Takamoto 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Kokubu Plant, Hitachi, Ltd.

Claims (6)

[Claims] 1. A high-voltage conductor, a container surrounding the high-voltage conductor and enclosing an insulating gas, a metal foreign matter capturing hole provided at a bottom of the container and protruding downward to capture metal foreign matter,
A gas-insulated switchgear having a hole through which the metal foreign matter can pass and a conductive cover covering an upper portion of the metal foreign matter capturing hole, wherein an electric field strength in a space above the conductive cover is greater than that of the metal foreign matter capturing hole. A gas-insulated switchgear, wherein holes provided in the conductive cover are distributed so as to increase as the distance from the center increases. 2. The conductive cover according to claim 1, wherein the holes provided in the conductive cover are distributed such that the porosity of the conductive cover increases as the position approaches the center of the metal foreign matter capturing hole. Gas insulated switchgear. 3. A high-voltage conductor, a container surrounding the high-voltage conductor and enclosing an insulating gas, a metal foreign matter capturing hole provided at a bottom of the container and projecting downward to capture metal foreign matter,
In a gas insulated switchgear provided with a net-like conductive cover covering an upper part of the metal foreign matter capturing hole, an equivalent diameter of a wire constituting the conductive cover becomes smaller as it is closer to the center of the metal foreign matter capturing hole. A gas-insulated switchgear, characterized in that it is configured. 4. A high-voltage conductor, a container surrounding the high-voltage conductor and enclosing an insulating gas, a metal foreign matter capturing hole provided at a bottom of the container and protruding downward to capture metal foreign matter,
A gas insulated switchgear having a hole through which the metal foreign matter can pass and a conductive cover covering an upper portion of the metal foreign matter capturing hole, wherein an electric field strength in a space above the conductive cover is greater than that of the metal foreign matter capturing hole. A gas-insulated switchgear, wherein the conductive cover is formed in a curved shape protruding upward so as to become larger as being closer to the center. 5. The method according to claim 1, wherein a plurality of conductive cylinders are provided concentrically in the metal foreign matter capturing hole in place of the conductive cover, and a radial interval between the plurality of conductive cylinders is provided. The gas insulated switchgear is configured to be larger as it is closer to the center of the metal foreign matter capturing hole. 6. A method according to claim 1, wherein a plurality of ring-shaped conductors are provided concentrically above said metal foreign matter capturing hole in place of said conductive cover, and a radial interval between said plurality of ring-shaped conductors is provided. The gas insulated switchgear is configured to be larger as it is closer to the center of the metal foreign matter capturing hole.