JP2000312422A - Insulation spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize reduction in size while maintaining the excellent reliability through optimum insulation property depending on the amplitude of unbalanced electric field, by arranging a plurality of grounding shields in different distances from a metal flange in the radial direction of an insulation spacer. SOLUTION: Since a grounding shield 14b to be arranged at the area near the bottom surface of a tank is arranged in the internal side in the radial direction of an insulation spacer 11 than the grounding shields 14a, 14c arranged at the area near the side surface of tank, unbalanced field at the bottom surface of the tank is reduced. Consequently, a remaining metal foreign matter can lower the electric field of the part where such foreign matter stays easily and reliability of insulation property can be improved. Moreover, since only the grounding shield 14b is arranged at the internal side in the radial direction of the insulation spacer 11, distance between two grounding shields arranged in the right and left areas and the corresponding high voltage conductors 13a, 13c can be shortened. Accordingly, the insulation spacer 11 can be reduced in size, while the excellent insulation reliability is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating spacer for supporting a high-voltage conductor mounted on a tank of a gas insulated switchgear, and more particularly to an insulating spacer having a ground shield embedded therein for suppressing an uneven electric field. It is about.

[0002]

2. Description of the Related Art Hitherto, a gas insulated switchgear has been proposed in which an insulating gas such as SF6 having a high dielectric strength is sealed in a tank to insulate a charged portion. The gas insulated switchgear is excellent in safety because the charging section is housed in the tank, and can be easily downsized by housing a plurality of conductors in the same tank. For this reason, gas insulated switchgears have been widely adopted in recent years, where the difficulty of land acquisition and the demand for environmental harmony are increasing when substation facilities are constructed.

By the way, an insulating spacer for supporting a high-voltage conductor is attached to a tank of a gas insulated switchgear. Since the insulating spacer supports the high-voltage conductor and is subjected to the pressure of the high-pressure gas during the gas division, it is required that the insulating spacer have both high electrical insulation performance and strong structural strength. Here, as a conventional example of the insulating spacer, an insulating spacer described in JP-A-3-45113 is used.
A specific description will be given with reference to FIGS. Note that FIG.
Is a cross-sectional view of the insulating spacer, and FIG. 10 is a vertical cross-sectional view of the insulating spacer.

[0004] The insulating spacer 1 is made of a thermosetting resin such as an epoxy resin, and a metal flange 2 is provided on an outer peripheral portion thereof. As shown in FIG. 10, grounded metal tanks 10 are attached to both sides of the metal flange 2, and each tank 10 has a three-phase high-voltage conductor 3.
a, 3b, and 3c are inserted. These high-voltage conductors 3a, 3b, 3c are mounted inside the outer periphery of the insulating spacer 1. At this time, as shown in FIG. 9, the high-voltage conductors 3a, 3b, and 3c are arranged at respective vertices of a right-angled isosceles triangle whose right-angled vertices are located below, and are concentric with the insulating spacer 1 and the metal flange 2. Are located in More specifically, the high-voltage conductor 3a is located at the vertex on the left side in the figure,
The high-voltage conductor 3b is the lower right-angled vertex in the figure, and the high-voltage conductor 3
“c” is arranged at each vertex on the right side in the figure.

[0005] A metal flange 2 and high voltage conductors 3a, 3b,
3c, an arc-shaped ground shield 4a, 4b, 4
c is embedded. Each ground shield 4a, 4b, 4
c is divided corresponding to each of the high-voltage conductors 3a, 3b, 3c, and is arranged concentrically with the insulating spacer 1 and the metal flange 2.

A connection member 5 having conductivity is connected to the ground shields 4a and 4b.
The connection member 6 having conductivity is connected to c.
The two ground shields 4a, 4b, 4c are electrically connected to each other. Further, a resistor 7 is connected to an end of the ground shield 4a, and a resistor 8 is connected to an end of the ground shield 4c. The ground shields 4a, 4b, 4c are connected via these resistors 7, 8, respectively. Grounded. The connection member 6 is connected to a measurement terminal 9 used for voltage measurement and corona measurement.

The insulating spacer 1 having the above configuration
When a voltage is applied to the high voltage conductors 3a, 3b, 3c, a voltage proportional thereto is applied to the ground shields 4a, 4b, 4c.
c induced. By extracting this induced voltage from the measurement terminal 9 to the outside, the voltage measurement and the corona measurement of the high-voltage conductors 3a, 3b, 3c can be performed.

Further, the grounding shields 4a, 4b, 4c are electrically connected by connecting members 5, 6, and the resistances 7,
8, three ground shields 4a,
Corona detection sensitivity equivalent to that obtained when a ground shield in which 4b and 4c are integrated into one is embedded. Also,
The ground shields 4a, 4b, 4c divided into three
Residual stress during casting and curing of the insulating spacer 1 can be reduced. As a result, the generation of cracks can be suppressed, which can greatly contribute to improving the reliability of the insulating spacer.

[0009]

In recent years, the size of the tank has been reduced in order to further reduce the size of the gas-insulated switchgear. As the tank size is reduced, the insulating spacers are also reduced, but this also increases the unequal electric field. In view of such a situation, with regard to insulation performance, it is more strictly required to suppress the uneven electric field on the surface of the high-voltage conductor and to suppress the uneven electric field on the bottom surface of the tank. Of these, the latter is particularly important for securing insulation performance when metal foreign matter remains. In the conventional example described above, the high-voltage conductors 3a, 3b, 3c and the ground
a, 4b and 4c are arranged.

However, in the above conventional example, the high voltage conductors 3a, 3b, 3c and the ground shields 4a, 4b, 4c
Were all the same in the radial direction of the insulating spacer. Therefore, the following problems have occurred.
That is, in the tank constituting the gas insulated switchgear, when comparing the possibility that metal foreign matter stays on the bottom surface and the side surface, the metal foreign matter is more likely to stay on the bottom surface than on the side surface. Therefore, the uneven electric field is higher at the tank bottom surface than at the tank side surface. Therefore, conventionally, the diameter of the tank and the diameter of the insulating spacer 1 are determined so as to suppress the uneven electric field at the bottom of the tank. In addition, the corners of the branch tank have a higher electric field inequality than a straight part of the tank, but the same insulating spacer 1 has been applied to both parts. Also in this case, the insulating spacer 1 capable of suppressing the higher uneven electric field has been employed.

As described above, the conventional insulating spacer 1
In the Japanese Patent Application Laid-Open No. H11-229, the insulation performance is ensured based on a portion having a high unequal electric field, and excessive insulation performance is obtained when a portion having a low unequal electric field is used as a reference. But,
The first is to ensure sufficient insulation performance to maintain excellent reliability, and this has been a limit in reducing the size of the insulating spacer 1.

The present invention has been proposed to solve the above-mentioned problems of the prior art, and an object of the present invention is to secure an optimum insulation performance according to the height of an uneven electric field. Accordingly, an object of the present invention is to provide an insulating spacer which can be reduced in size while maintaining excellent reliability.

[0013]

In order to achieve the above object, the present invention provides a metal flange provided on an outer periphery, a plurality of high-voltage conductors mounted inside the outer periphery, and An insulating spacer in which a ground shield is embedded corresponding to each high voltage conductor at an intermediate portion between each high voltage conductor has the following features.

The invention according to claim 1 is characterized in that the plurality of ground shields are arranged at different distances from the metal flange in the radial direction of the insulating spacer.

According to the first aspect of the present invention having the above structure, in a portion where the uneven electric field is high, the ground shield corresponding to the portion is arranged radially inside the insulating spacer, so that the uneven electric field is reduced. Only, the optimum insulation performance according to the height of the unequal electric field can be secured. That is, it is not necessary to ensure insulation performance with reference to a portion having the highest unequal electric field, and excessive insulation performance can be eliminated. This makes it possible to shorten the distance between the ground shield other than the ground shield disposed radially inside the insulating spacer and the corresponding high-voltage conductor, and maintains excellent reliability while maintaining excellent reliability. Can be reduced.

According to a second aspect of the present invention, in the insulating spacer according to the first aspect, the high voltage conductor is provided at each vertex of a triangle in which one vertex is located below and the other two vertices are located on the left and right. Are related to the three-phase insulating spacers. First, according to a second aspect of the present invention, the ground shield corresponding to the high-voltage conductor disposed at the lower vertex is:
It is characterized in that it is arranged radially inside the insulating spacer with respect to other ground shields.

According to the second aspect of the present invention, the ground shield corresponding to the high-voltage conductor located below, that is, the ground shield near the bottom of the tank when the insulating spacer is attached to the tank, is replaced with another ground shield. By arranging the insulating spacer radially inside the insulating spacer, it is possible to suppress an uneven electric field near the bottom of the tank where metal foreign matter is likely to stay. Therefore, the distance between the left and right ground shields and the corresponding high-voltage conductor can be shortened, and the size of the insulating spacer can be reduced while maintaining excellent reliability.

On the other hand, in the invention according to claim 3, at least one of the ground shields corresponding to the high-voltage conductors disposed at the left and right vertices is disposed radially inside the insulating spacer relative to the other ground shields. It is characterized by:

According to the third aspect of the present invention, one or both of the ground shields corresponding to the high voltage conductors located on the left and right, that is, the ground shield near the side of the tank when the insulating spacer is attached to the tank. Is arranged radially inside the insulating spacer relative to the other ground shields, it is possible to suppress the uneven electric field on the tank side surface at the corners of the branch tank where the uneven electric field is high. Therefore, at least the distance between the ground shield disposed below and the corresponding high-voltage conductor can be reduced, and the insulating spacer can be reduced in size while maintaining excellent reliability.

According to a fourth aspect of the present invention, in the insulating spacer according to the first, second or third aspect, the ground shield is arranged such that ends of adjacent ground shields overlap in the radial direction of the insulating spacer. It is characterized by the following.

According to the fourth aspect of the present invention, it is possible to eliminate a portion having no ground shield in the radial direction of the insulating spacer. Therefore, the potential does not leak from the gap between the adjacent ground shields to the outside in the radial direction of the insulating spacer, and the insulation performance can be further improved. Further, by completely covering the high-voltage conductor with the ground shield, the area of the corona detecting section is increased, and the detection sensitivity at the time of corona measurement is improved.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment: Corresponding to Claims 1 and 2 [Configuration] Hereinafter, a first embodiment including claims 1 and 2 of the present invention will be described with reference to FIGS. This will be specifically described with reference to FIG. FIG. 1 is a transverse sectional view, and FIG. 2 is a longitudinal sectional view.

The insulating spacer 1 is made of a thermosetting resin such as an epoxy resin, and a metal flange 12 is provided on an outer peripheral portion thereof. Tanks 20 (shown in FIG. 2) are mounted on both sides of the metal flange 12, and three-phase high-voltage conductors 13a, 13b, and 13c are inserted into each tank 20. Then, these high-voltage conductors 13a, 1
3 b and 13 c are mounted inside the outer peripheral portion of the insulating spacer 11. The high-voltage conductors 13a, 13b, and 13c are arranged at the vertices of a right-angled isosceles triangle, and are arranged concentrically with the insulating spacer 11 and the metal flange 12. More specifically, the high voltage conductor 13a is disposed at the left vertex in the drawing, the high voltage conductor 13b is disposed at the lower right vertex in the drawing, and the high voltage conductor 13c is disposed at the right vertex in the drawing.

The metal flange 12 and the high voltage conductors 13a, 1
3b and 13c, an arc-shaped ground shield 14 is provided in order to prevent insulation characteristics from deteriorating due to an uneven electric field.
a, 14b and 14c are embedded. Each ground shield 14a, 14b, 14c is connected to each high voltage conductor 13a, 13
b, 13c, the insulating spacer 1
1 and the metal flange 12.

The distances A, B and C between the ground shields 14a, 14b and 14c and the metal flange 12 are as follows.

## EQU1 ## The arrangement is such that B> A = C. That is, the ground shield 14 corresponding to the high-voltage conductor 13b disposed at the lower vertex
b is disposed radially inside the insulating spacer 11 with respect to the other ground shields 14a and 14c.

A conductive connection member 15 is connected to the ground shields 14a and 14b. Similarly, a conductive connection member 16 is connected to the ground shields 14b and 14c, and the three ground shields 14a and 14c are connected to each other.
4b and 14c are electrically connected. Further, a resistor 17 is connected to an end of the ground shield 14a, and a resistor 18 is connected to an end of the ground shield 14c. The ground shield 14a,
14b and 14c are grounded. The connection member 16
Is connected to a measurement terminal 19 used for voltage measurement and corona measurement.

[Operation / Effect] The operation / effect of the first embodiment having the above configuration is as follows. That is, since the ground shield 14b disposed near the bottom of the tank 20 is disposed radially inward of the insulating spacer 11 from the ground shields 14a and 14c disposed near the side of the tank 20, The unequal electric field can be reduced. As a result, the electric field in the P portion and the Q portion (shown in FIG. 2) where the remaining metal foreign matter easily stays can be reduced, and the reliability of the insulation performance can be improved.

Further, since only the ground shield 14b is arranged radially inside the insulating spacer 11, the remaining two ground shields 14a and 14c arranged on the left and right and the high-voltage conductors 13a and 13c corresponding to the two shields are arranged. Can be shortened. Therefore, it is possible to reduce the size of the insulating spacer 11 while maintaining excellent insulation reliability.

(2) Second Embodiment Corresponding to Claims 1 and 3 [Structure] Next, a second embodiment of the present invention including claims 1 and 3 will be described with reference to FIGS. This will be described specifically. FIG. 3 is a transverse sectional view, and FIG. 4 is a horizontal sectional view.
Note that the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 4, a linear tank 20 and an L-shaped tank 21 are attached to the metal flange 12 of the insulating spacer 11. Bent conductors 22a, 22b, and 22c are inserted into the L-shaped tank 21, and the high-voltage conductor 1
The insulating spacers 11 are arranged in the same manner as 3a, 13b and 13c.
Is mounted on the inside of the outer periphery.

The ground shields 14a, 14b, and 14c are arranged at an intermediate portion between the high-voltage conductors 13a, 13b, and 13c and the metal flange 12, and the distances A, B, and C from the metal flange 12 are as follows.

## EQU2 ## A is arranged in a relation of A> B = C. That is, in the second embodiment, only the ground shield 14a corresponding to the high-voltage conductor 13a disposed at the left vertex is different from the other ground shields 14a.
The insulating spacer 11 is disposed radially inward of the insulating spacers 11 from b and 14c.

[Operation / Effect] In the second embodiment having the above configuration, the ground shield 14a is located inside the bent portion of the L-shaped tank 21, and the other two ground shields 14b, The insulating spacer 11 is disposed radially inward of the insulating spacer 14c. Therefore, the L-shaped tank 21
In the R portion (shown in FIG. 4), which is a corner portion, the uneven electric field can be prevented from increasing, and the reliability of the insulation performance can be improved. Also, the ground shield 14a
Since only the insulating spacer 11 is arranged radially inside,
The distance between the remaining two ground shields 14b, 14c and the high voltage conductors 13b, 13c can be reduced, and the insulating spacer 11 can be reduced while maintaining excellent insulation reliability.

(3) Third Embodiment Corresponding to Claims 1 and 3 [Structure] Next, a third embodiment of the present invention, including Claims 1 and 3, will be described with reference to FIGS. This will be described specifically. FIG. 5 is a horizontal sectional view, and FIG. 6 is a horizontal sectional view. The same members as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 6, the metal flange 12 of the insulating spacer 11 is attached to a linear tank 20 and a T-shaped tank 23. Bent conductors 24a, 24b, 24c are inserted into the T-shaped tank 23, and are mounted inside the outer peripheral portion of the insulating spacer 11 in the same arrangement as the high-voltage conductors 13a, 13b, 13c.

The ground shields 14a, 14b, and 14c are disposed at an intermediate portion between the high-voltage conductors 13a, 13b, and 13c and the metal flange 12, and the distances A, B, and C between the metal flanges 12 are as follows.

## EQU3 ## Arrangements are made in a relationship of A = C> B. That is, in the third embodiment, the high-voltage conductors 13a and 13c
Are disposed radially inside the insulating spacer 11 with respect to the ground shield 14b below.

[Operation and Effect] In the third embodiment having the above configuration, the ground shields 14a, 1
4c is located inside the bent portion of the T-shaped tank 23, and the insulating spacer 11 is smaller than the lower ground shield 14b.
Are arranged radially inside. For this reason, it is possible to suppress an increase in the uneven electric field in the R portions (shown in FIG. 6), which are two corners of the T-type tank 23, and to improve the insulation performance. Also, the lower ground shield 14
Since the distance between b and the high voltage conductor 13b can be shortened, it is possible to maintain both excellent insulation reliability and downsizing of the insulating spacer 11.

(4) Fourth Embodiment: Claims 1 and 2
Fourth Embodiment [Configuration] A fourth embodiment of the present invention, including claims 1, 2 and 4, will be specifically described with reference to the cross sectional view of FIG. The fourth embodiment is a modification of the first embodiment, and its vertical sectional view is the same as that of FIG. The same members as those in the first to third embodiments are denoted by the same reference numerals, and description thereof will be omitted.

The configurational features of the fourth embodiment are as follows. That is, the ground shields 14a, 14b, 14
c is configured to have a bow length such that the ends thereof are surely overlapped in the radial direction, and the ends of the adjacent ground shields 14a, 14b, 14c
1 are arranged so as to overlap in the radial direction.
At this time, in the fourth embodiment, as in the first embodiment, the ground shield 14b is disposed radially inward of the insulating spacer body 11 from the remaining two ground shields 14a and 14c. Both ends of the ground shield 14b are arranged inside the ends of the ground shields 14a and 14c.

[Operation / Effect] The fourth embodiment having the above configuration has the following operation and effect in addition to the operation and effect of the first embodiment. When a voltage is applied to the high-voltage conductors 13a, 13b, and 13c, an electric field is induced in accordance with the voltage.
a, 13b, and 13c are all ground shields 14a,
It is covered with 14b and 14c. Therefore, the induced electric field does not leak from the insulating spacer 11, and the reliability of the insulating spacer 11 is improved. Further, the high voltage conductors 13a, 13a are connected to the ground shields 14a, 14b, 14c.
Since b and 13c are completely covered, the area for detecting the corona signal can be increased, and the detection sensitivity at the time of corona measurement is improved.

(5) Fifth Embodiment: Claims 1 and 3
Fourth Embodiment [Structure] A fifth embodiment of the present invention, including claims 1, 3 and 4, will be specifically described with reference to the cross sectional view of FIG. The fifth embodiment is a modification of the third embodiment, and its horizontal sectional view is the same as that of FIG. Note that the same members as those in the first to fourth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

The fifth embodiment is similar to the fourth embodiment in that adjacent ground shields 14a, 14b, 1
4c are arranged so that their ends overlap in the radial direction of the insulating spacer 11. However, in the fifth embodiment, similarly to the third embodiment, the ground shield 13
Since a and 13c are disposed radially inward of the insulating spacer body 11 with respect to the lower ground shield 14b,
Both ends of the ground shield 14b are connected to the ground shield 14a,
14c will be located outside the end. .

[Operation and Effect] According to the fifth embodiment having such a configuration, the operation and effect of the third and fourth embodiments can be combined.

[0043]

As described above, according to the insulating spacer of the present invention, the ground shield corresponding to each high-voltage conductor is provided at the intermediate portion between the metal flange of the insulating spacer body and each high-voltage conductor. By embedding at different distances from the flange, it is possible to arrange a ground shield that can ensure the optimum insulation performance according to the height of the unequal electric field, and contribute to downsizing while maintaining excellent reliability. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the first embodiment.

FIG. 3 is a cross-sectional view of a second embodiment of the present invention.

FIG. 4 is a horizontal cross-sectional view of the second embodiment.

FIG. 5 is a cross-sectional view of a third embodiment of the present invention.

FIG. 6 is a horizontal sectional view of a third embodiment.

FIG. 7 is a cross-sectional view of a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view of a fifth embodiment of the present invention.

FIG. 9 is a cross-sectional view of a conventional insulating spacer.

FIG. 10 is a longitudinal sectional view of a conventional insulating spacer.

[Explanation of symbols]

1, 11: insulating spacer 2, 12: metal flange 3a, 3b, 3c, 13a, 13b, 13c: conductor 4a, 4b, 4c, 14a, 14b, 14c: ground shield 5, 6, 15, 16: connecting member 7 , 8, 17, 18 ... resistor 9, 19 ... measuring terminal 10, 20 ... tank 21 ... L-shaped tank 22a, 22b, 22c, 24a, 24b, 24c ... bent conductor 23 ... T-shaped tank

Claims (4)

[Claims] A metal flange is provided on an outer peripheral portion, a plurality of high-voltage conductors are mounted inside the outer peripheral portion, and an intermediate portion between the metal flange and each of the high-voltage conductors corresponds to each of the high-voltage conductors. An insulating spacer in which a ground shield is embedded, wherein the plurality of ground shields are arranged at different distances from the metal flange in a radial direction of the insulating spacer. 2. The high-voltage conductor is disposed at each vertex of a triangle in which one vertex is located below and the other two vertices are located on the left and right, and corresponds to the high-voltage conductor located at the lower vertex. The insulating spacer according to claim 1, wherein the ground shield is disposed radially inside the insulating spacer with respect to other ground shields. 3. The high-voltage conductor is disposed at each vertex of a triangle in which one vertex is located below and the other two vertices are located on the left and right, and corresponds to the high-voltage conductors disposed on the left and right vertices. 2. The insulating spacer according to claim 1, wherein at least one of the ground shields is disposed radially inside the insulating spacer with respect to the other ground shields. 4. The ground shield is arranged so that ends of adjacent ground shields overlap in a radial direction of an insulating spacer.
Or the insulating spacer according to 3.