JPH11164428A - Gas insulation switch gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain electric field relaxation of an embedded electrode or a vacuum circuit breaker electrode, and reduce the overall shape, by disposing a plurality of the cylindrical embedded electrodes at respective corners while facing fitting part of a supporting insulator, and integrally-molding the embedded electrodes with epoxy resin. SOLUTION: Embedded electrodes 26, 27 are of cylindrical shape, which facilitate processing. By forming the embedded electrodes 26, 27 into a cylindrical shape from an oval shape, and disposing them at a corner part respectively, a sufficient insulation distance can be ensured, so that residual stress at the time of curing and shrinking of epoxy resin can be dispersed for reduction. In the case of the oval shape, the contact point of a curvature part and a linear part becomes discontinuous, so that stress may be concentrated, though, by forming it into a round as a cylindrical shape, the stress becomes uniform in an electrode surface, a high stress part is eliminated and reduced further. It is thus possible to reduce the thickness of an insulating layer from the embedded electrodes 26, 27 to the edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas insulated switchgear.

[0002]

BACKGROUND OF THE INVENTION In FIG. 6 illustrating a configuration example of a typical gas-insulated switchgear, surrounded airtightly periphery mild steel plate, and the interior of the box body 1 partitioned into several, such as SF ₆ gas The insulating gas 2 is sealed, and a disconnector 3A is accommodated in the upper chamber 1a, and a vacuum circuit breaker 4 and a disconnector 3b having the same shape as the upper disconnector 3A are accommodated in the lower chamber 1b. Reference numeral 7 denotes a power receiving cable head, 8 denotes a power cable, and 9 denotes a through-type current transformer penetrated by the power cable, and power is received by these. The storage devices in the insulating gas are connected to each other by a main circuit conductor 6, and the main circuit conductor 6 is supported and fixed by a support insulator 5.

[0003] A T-shaped aerial-gas bushing 10 provided on the ceiling portion of the box body 1 connects adjacent boards which are arranged vertically in the drawing. Here, the circuit breaker 4 is
As shown in FIG.
2 and 13 are attached, and the electrodes 12 and 13 are fixed by supporting insulators 14 and 15. Also, between the electrodes 12-1
3 is provided with an insulating plate 16 substantially parallel to the vacuum valve 11. As a result, the vacuum valve 11 is fixed, and the space between the electrodes (not shown)
It is opened and closed by an operating mechanism 19 via an insulated operating rod 18 connected to a Scott Russell mechanism 17 for converting a vertical motion into a horizontal motion disclosed in US Pat. In addition, connection to other storage devices is performed by the contacts 20 a and 20 b provided on the upper and lower electrodes 12 and 13.

[0004]

In such a configuration, the lower electrode 13 is enlarged to accommodate a relatively large structure such as the Scott Russell mechanism 17, and is formed in a substantially square shape corresponding to the outer shape of the Scott Russell mechanism 17. The shape of the body. Therefore, the size of the support insulator 15 for supporting and fixing the lower electrode 13 is also increased.

In general, as disclosed in Japanese Utility Model Application Laid-Open No. 60-128425, a buried electrode of a supporting insulator is a pair of electrodes having substantially the same upper and lower sides, but as shown in FIG. A plurality of embedded electrodes 21a, 2
1b, 21c. The support insulator in which the plurality of elliptical electrodes 21a, 21b, and 21c are molded with the epoxy resin 22 requires a lot of man-hours because the electrodes are processed in an elliptical manner, and the insulating distance between the electrodes is different and the epoxy resin 22 is not uniform. Causes severe curing shrinkage. For this reason, it is necessary to increase the number of insulating layers so that the curing shrinkage becomes uniform, which further increases the size. Reference numeral 23 denotes an opening provided to reduce the amount of epoxy resin, and reference numeral 24 denotes an operation rod. Here, when a single buried electrode is used, the buried electrode becomes large and heavy, so that the molding time tends to be long in order to improve the heat distribution during molding.

The lower electrode 13 has a substantially rectangular shape, but must have a large curvature to relax the electric field. The shield used for electric field relaxation is disclosed in
As disclosed in US Pat. No. 2,210,107, an integrally formed electrode having a large curvature is used. Therefore, the electrode 13
It itself becomes large, and the number of processing steps increases, and it becomes heavy. For this reason, the vacuum circuit breaker itself becomes large.

[0007] Accordingly, the size of the support insulator and the vacuum circuit breaker to be accommodated is increased, so that the gas insulated switchgear is also increased in size, which has been against the recent trend of downsizing. An object of the present invention is to provide a gas insulated switchgear having a reduced overall shape by reducing the electric field of a buried electrode of a supporting insulator to be housed or an electrode of a vacuum circuit breaker and reducing the size of the supporting insulator and the vacuum circuit breaker. Is to do.

[0008]

In order to achieve the above object, according to the present invention, a support insulator is attached to a partition plate of a box in which an electric device is housed, and an upper electrode and a lower electrode of a vacuum circuit breaker are supported by an insulator. In the gas insulated switchgear supported and fixed by the supporting insulator, the supporting insulator has a mounting portion based on the electrode shape, and a plurality of cylindrical embedded electrodes are arranged at each corner portion at least in opposition to the mounting portion. Is molded integrally with epoxy resin.

In such a configuration, the distance between the embedded electrodes in the support insulator is sufficiently ensured, so that the stress at the time of curing shrinkage of the epoxy resin is reduced, and the gas insulated switch gear is reduced.

The present invention also provides a gas insulated switchgear in which a support insulator is attached to a partition plate of a box in which an electric device is housed, and an upper electrode and a lower electrode of the vacuum circuit breaker are supported and fixed by the support insulator. The vacuum circuit breaker includes an operation mechanism for opening and closing one of the upper electrode and the lower electrode, and the electrode includes an inner electrode in which the operation mechanism is housed and an outer electrode for an electric field reduction shield. The gist is that the inner electrode is made larger than the outer electrode so that the electric field strength of the inner electrode and the outer electrode is minimized.

In such a configuration, the inner electrode is divided into an inner electrode for accommodating the operation mechanism portion and an outer electrode for shielding the electric field, and the inner electrode is made smaller than the outer electrode so as to minimize the electric field strength of the inner electrode and the outer electrode. Since the size is increased, the overall shape of the vacuum circuit breaker can be reduced, and the size of the gas insulated switchgear can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the gas insulated switchgear of the present invention will be described with reference to the drawings.
The same components as those in the related art are denoted by the same reference numerals. FIG. 1 is a side view showing an embodiment of a vacuum circuit breaker in a gas insulated switchgear of the present invention. In the figure, electrodes 12 and 13 provided above and below a vacuum valve 11,
Support insulators 14, 1 for supporting and fixing the electrodes 12, 13
5, an insulating plate 16 provided between the electrodes 12-13, a Scott Russell mechanism 17 for opening and closing the electrodes of the vacuum valve 11 not shown, an insulating operating rod 18, and an operating mechanism 1.
9, and contacts 20a, 20b used for connection of the main circuit
Has the same configuration as the conventional one. Here, the lower electrode 13 is provided with a shield 25 for relaxing the electric field.

FIG. 2 is a sectional view showing an embodiment of a support insulator in the gas insulated switchgear of the present invention. In the figure, the support insulator 15 is different from the conventional one in the shape and arrangement of the embedded electrode, and is different from the conventional one in that the cylindrical embedded electrode
Reference numerals 6 and 27 are provided at the corners of the substantially square supporting insulator 15 respectively. These embedded electrodes 26, 2
Reference numeral 7 denotes a conductive layer 28 coated with, for example, a conductive paint or the like, which has the same potential. FIG. 3 shows a cross-sectional view thereof. A U-shaped groove 30 is provided in the insulating layer 29, and the conductive layer 28 is formed on the inner surface of the groove 30. The conductive layer 28 is formed several mm inward along the shape of the Scott Russell mechanism 17 on the vacuum circuit breaker 4 side and the shield 25 for reducing the electric field. Reference numeral 23 denotes an opening provided to reduce the amount of epoxy resin.

In such a configuration, the embedded electrode 2
The processing of 6, 27 is easy because they are cylindrical. Further, since the embedded electrodes 26 and 27 are arranged at the corners from an elliptical shape to a cylindrical shape, a sufficient insulation distance can be secured, and thus the residual stress when the epoxy resin cures and shrinks is dispersed. Can be made smaller. In addition, in the elliptical shape, the contact point between the curvature part and the straight part becomes discontinuous and stress concentrates. Can be done. As described above, since the residual stress can be reduced, the embedded electrode 2
The thickness of the insulating layer from 6, 27 to the end can be reduced.

Since these electrodes 26 and 27 are at the same potential, they have the same effect as the presence of an apparently large electrode, and the electric field of the shield 25 to be attached can be reduced. Further, the weight of the support insulator 15 can be reduced.

Here, since the conductive layer 28 is formed several mm inside the shield 25, the electric field concentration at the end of the conductive layer 28 can be prevented. According to the research by the present inventors, if the conductive layer 28 is formed extremely inside, the electric field of the shield 25 cannot be reduced. In the present embodiment, when the height of the support insulator 15 is 140 mm and the shield 25 is a substantially square body having a side of 170 mm, forming the shield 25 inside 3 mm has a good electric field suppressing effect.

FIG. 4 is a view for explaining the operation mechanism of the vacuum circuit breaker. In the figure, with respect to the shield 25 in FIG. 1, a Scott Russell mechanism 31 is attached to an inverted U-shaped mechanism housing 32 using a steel plate having mechanical strength, and a vacuum (not shown) is connected by an operating shaft 33 connected thereto. The valve is being opened and closed. Outside the mechanism housing portion 32, an electric field alleviating shield 34 made of an aluminum alloy that is lightweight and easy to process is fixed with bolts 35. An end of the mechanism accommodating portion 32 and the end of the shield 34 are provided with a step a with a constant curvature.

Here, the electric field strength of the mechanism accommodating section 32 is set to E ₁
And to show the change in electric field intensity due to the step a in a case where the shield 34 and E ₂ in Fig. In FIG. 5, the electric field strengths intersect due to the step a. In the study of the present inventors, when a = 5 mm, the electric field strengths E ₁ and E ₂ have the lowest values. In other words, the withstand voltage characteristics are improved where the electric field strength is lowest, and the shield 34 and the like can be reduced in size.

The mechanical strength and size of the mechanism housing 32 are determined in accordance with the stress and operating range of the operating mechanism. On the other hand, since the shield 34 has a slightly smaller shape for electric field relaxation, the electric field relaxation can be performed with a small volume while having mechanical strength as a whole shape.

Further, the curvature of the shield 34 may be small since the inside is in contact with the mechanism operating section 32. Therefore,
Since the outer curvature can be increased, the electric field can be further alleviated.

Further, as another embodiment, if the shields are superposed in a plurality of stages, each shield can reduce the electric field with a small curvature, and the overall shape can be reduced.

As described above, the entire shape can be reduced by relaxing the electric field of the components of the supporting insulator and the vacuum circuit breaker to be housed, and as a result, the gas insulated switchgear can be reduced.

[0023]

As described above, according to the present invention, the support insulator is attached to the partition plate of the box housing the electric device, and the upper and lower electrodes of the vacuum circuit breaker are supported and fixed by the support insulator. In a gas insulated switchgear, the supporting insulator has a mounting portion based on the electrode shape, and a plurality of cylindrical embedded electrodes are arranged at each corner at least facing the mounting portion, and the embedded electrode is made of epoxy resin. Since they are integrally molded, the stress at the time of curing and shrinking of the epoxy resin is alleviated, and the overall shape can be reduced.

Further, in a gas insulated switchgear in which a support insulator is attached to a partition plate of a box in which an electric device is stored, and an upper electrode and a lower electrode of the vacuum circuit breaker are supported and fixed by the support insulator, An operation mechanism for opening and closing operation is housed in one of the upper electrode and the lower electrode, and the electrode is constituted by an inner electrode in which the operation mechanism is housed and an outer electrode for electric field relaxation shield,
Since the inner electrode is made larger than the outer electrode so that the electric field strength of the inner electrode and the outer electrode is minimized, the overall shape can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a vacuum circuit breaker in a gas insulated switchgear of the present invention.

FIG. 2 is a sectional view showing an embodiment of a support insulator of the gas insulated switchgear of the present invention.

FIG. 3 is a sectional view of a main part of FIG. 2;

FIG. 4 is a diagram illustrating an operation mechanism of the vacuum circuit breaker in FIG. 1;

FIG. 5 is a view for explaining the electric field strength in the electrode arrangement in FIG. 4;

FIG. 6 is a configuration diagram of a typical gas-insulated switchgear.

FIG. 7 is a side view of the vacuum circuit breaker 4 of FIG.

FIG. 8 is a cross-sectional view of the support insulator 5 of FIG.

[Explanation of symbols]

4: vacuum circuit breaker, 13: lower electrode, 15: supporting insulator,
25, 34: shield, 26, 27: embedded electrode, 2
8: conductive layer, 29: insulating layer

Claims (4)

[Claims] 1. A gas-insulated switchgear wherein a support insulator is attached to a partition plate of a box in which an electric device is housed, and an upper electrode and a lower electrode of a vacuum circuit breaker are supported and fixed by the support insulator. Has a mounting portion based on the electrode shape, a plurality of cylindrical embedded electrodes are arranged at each corner portion at least facing the mounting portion, and the embedded electrodes are integrally molded with epoxy resin. Gas insulated switchgear. 2. The gas insulated switchgear according to claim 1, wherein a conductive layer is provided on a plurality of electrodes arranged at the corners of said support insulator. 3. A gas-insulated switchgear, wherein a support insulator is attached to a partition plate of a box in which an electric device is stored, and an upper electrode and a lower electrode of a vacuum circuit breaker are supported and fixed by the support insulator. An operating mechanism for opening and closing the upper electrode and the lower electrode is housed in one of the upper electrode and the lower electrode, and the electrode includes an inner electrode in which the operating mechanism is housed and an outer electrode for an electric field reduction shield. A gas-insulated switchgear wherein the inner electrode is larger than the outer electrode so that the electric field strength of both electrodes is minimized. 4. The gas insulated switchgear according to claim 3, wherein the curvature of the outer electrode is greater than the curvature of the inner side in contact with the inner electrode.