JPH02114813A - Gas insulated bus - Google Patents

Abstract

PURPOSE:To prevent flotation of conductive foreign matter by making the insulating spacer for one conductor, at the bottom of a container, of three-phase conductors being supported through the insulating spacers in a grounded metallic container encapsulating insulating gas longer than those for other conductors. CONSTITUTION:A metallic container 1 encapsulating insulating gas 4 is grounded and one ends of insulating spacers 3a-3c for three-phase lines are fixed therein. The insulating spacer 3a at the bottom of the container 1 is made longer than other spacers 3b, 3c, and the dimension of the high voltage conductor 2a being supported at the other end of the spacer from the inner wall of the metallic container 1 is made larger than those for other conductors 2b, 2c. After passing through the section of the spacer 3a, the conductor 2a is separated from the pipe wall by the dimension identical to those of the conductors 2b, 2c. By such arrangement, dielectric breakdown due to flotation of conductive foreign matter from the bottom of pipe can be prevented without sacrifice of insulation performance.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement in a container for, for example, a three-phase finger-shaped gas insulated bus bar, which houses a high voltage AC bus bar used in a gas insulated switchgear. .

[Prior Art] FIG. 3 is a sectional view of a conventional three-phase finger-shaped gas insulated bus bar. In the figure, three-phase electrical circuit conductors 2 are housed in a grounded metal container 1, and are insulated and fixed via insulating spacers 3, respectively.

An insulating gas 4 is sealed inside the metal container 1.

The electric circuit conductors 2 of each of the three phases are arranged so that the axis of each electric circuit conductor 2 is located at the apex of a right-angled isosceles triangle in a cross section in a plane perpendicular to the axis of the metal container, and each of the electric circuit conductors 2 of each phase are arranged parallel to. The electrical circuit conductor 2 disposed at the right-angled apex of this right-angled isosceles triangle is fixed to the bottom of the metal container 1 via an insulating spacer 3.

In this way, the electric circuit conductors 2 of each of the three phases are arranged at the same distance from the grounded metal container l.

[Problems to be Solved by the Invention] Since the conventional gas insulated bus bar is configured as described above, it is possible to prevent conductive foreign matter, such as bolts, from forming on the inner bottom surface of the metal container near the insulating spacer fixed to the bottom of the metal container. If there are foreign objects such as metal particles or metal particles, the foreign objects may float up when the electric field value at the bottom of the metal container is high and adhere to the insulating spacer. This caused a problem in that the insulation performance of the gas insulated bus bar deteriorated. To solve this problem, it is necessary to keep the electric field value at the bottom of the metal container low.

This invention was made to solve the above-mentioned problems, and aims to suppress the floating of conductive foreign matter near the insulating spacer fixed to the bottom and obtain a gas-insulated bus bar with high insulation performance. .

[Means for Solving the Problems] A gas insulated bus bar according to the present invention includes a metal container filled with an insulating gas and grounded, and an insulating spacer housed in the metal container and having one end fixed to the inner wall of the container. and an insulating spacer, which is fixed to the other end of the insulating spacer, and which is arranged at each vertex of an isosceles triangle in a cross section taken in a plane perpendicular to the axis of the metal container, and whose one end is fixed to the bottom of the container. The three-phase electrical circuit conductor has a portion raised toward the axis of the metal container from the bottom of the container only near the portion fixed to the end.

[Function] Among the three-phase electric circuit conductors stored and fixed in the metal container, the electric circuit conductor supported by the insulating spacer fixed to the bottom of the metal container is The electrical circuit conductor is made long, and therefore the distance from the metal container increases only in the vicinity of the supporting portion of the electrical circuit conductor supported by the long insulating spacer.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a sectional view showing a gas insulated bus bar according to an embodiment of the present invention, and FIG. 2 is a sectional side view of the gas insulated bus bar shown in FIG. 1. In the figure, three-phase circuit conductors 2a, 2b, and 2c are housed in a grounded metal container l.
They are insulated and fixed via insulating spacers 3a, 3b, and 3c, respectively. An insulating gas 4 is sealed inside the metal container l. Three-phase circuit conductors 2a, 2b, 2c for each phase
is a cross section in a plane perpendicular to the axis of the metal container,
It is placed at each vertex of an isosceles triangle. The electrical circuit conductor 2a disposed at the vertex of the angle between the isosceles sides of this isosceles triangle is fixed to the bottom of the metal container 1 via an insulating spacer 3a. This insulation spacer 3
Spacer a is made longer than insulating spacers 3b and 3c that support the electrical circuit conductors 2b and 2c of other phases, and is spaced apart from the metal container 1 to support the electrical circuit conductor 3a. Electrical circuit conductor 2a supported by this long insulating spacer 3a
The distance from the metal container l increases only in the vicinity of its supporting portion.

With the above configuration, the bottom of the metal container 1 to which the insulating spacer 3a is fixed is located away from the electrical circuit conductor 2a. Therefore, the electric field value due to the electric circuit conductor 2a at the bottom of the metal container 1 decreases. This allows the metal container l
Even if there is a conductive foreign object, such as a dropped bolt, near the insulating spacer 3a fixed to the bottom of the metal container 1, the electric field value near the insulating spacer 3a at the bottom of the metal container 1 has decreased, so it will not be conductive. There is no risk of surfacing of sexual foreign substances. Further, in the present invention, the electric circuit conductor 2a supported by the insulating spacer 3a fixed to the bottom of the metal container 1 is arranged so that the portion of the electric circuit conductor 2a to which the insulating spacer 3a is fixed is separated from the metal container 1. The electric circuit conductor 2a in the part where the insulating spacer 3a is not fixed is connected to the electric circuit conductor 2 of the other two phases.
b, 2c are arranged at the same distance from the metal container 1. In a cross section in a plane perpendicular to the axis of the metal container in a portion where this insulating spacer 3a is not fixed, the electric circuit conductors 2a, 2 of each of the three phases are
b and 2c are placed at the respective vertices of a right-angled isosceles triangle.

As described above, each of the electric circuit conductors 2a, 2b, 2c
is arranged, the part of the circuit conductor 2a to which the insulating spacer 3a is fixed has a shorter interphase distance with other phases; In the part of the electric circuit conductor 2a, the same interphase distance as that of other phases can be maintained.

As described in "Effects of the Invention" 2, according to the present invention, the insulating spacer that supports the electrical circuit conductor from the bottom of the metal container is made longer than the insulating spacer that supports the electrical circuit conductors of the other two phases. It is possible to keep the electric field value in the vicinity lower than in other parts. Thereby, floating of conductive foreign matter near the insulating spacer at the bottom of the metal container can be suppressed. Since only the supporting portion of the electrical circuit conductor fixed to the bottom of the metal container is lifted toward the axis of the metal container, floating of conductive foreign matter can be prevented while maintaining insulation performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a gas insulated bus bar according to an embodiment of the present invention, FIG. 2 is a sectional side view of the embodiment of FIG. 1,
FIG. 3 is a sectional view showing a conventional gas insulated bus bar. In the figure, 1 is a metal container, 2a, 2b, and 20 are electrical circuit conductors, 3a, 3b, and 30 are insulating spacers, and 4 is an insulating gas. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A metal container filled with an insulating gas and grounded, an insulating spacer housed in the metal container and having one end fixed to the inner wall of the container, and an insulating spacer fixed to the other end of the insulating spacer and attached to the shaft of the metal container. The axis of the metal container is removed from the bottom of the container only in the vicinity of the part fixed to the other end of the insulating spacer, which is disposed at each vertex of an isosceles triangle in the cross section in the orthogonal plane and has one end fixed to the bottom of the container. A gas-insulated busbar comprising: a three-phase electrical circuit conductor having a portion raised toward .