Gas-insulated electric apparatus and manufacturing method of gas-insulated electric apparatus

Patent metadata

Field	Value
Publication number	US-11031765-B2
Application number	US-201716316157-A
Country	US
Kind code	B2
Filing date	Jan 30, 2017
Priority date	Jul 13, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A gas-insulated electric apparatus includes: a sealed container made of metal; a high-voltage conductor, housed within the sealed container, that receives voltage; an insulating support member that insulates the high-voltage conductor from the sealed container and support the high-voltage conductor to the sealed container; and a nonlinear-resistance film covering at least a portion of an inner surface of the sealed container, the portion being on a lower side of the inner surface with respect to the high-voltage conductor. The nonlinear-resistance film is formed by particles of a nonlinear-resistance material and an insulating material, and the particles of the nonlinear-resistance material are dispersed in the insulating material. The particles of the nonlinear-resistance material are placed in the insulating material such that one or more of the particles of the nonlinear-resistance material is in constant contact with a conductive foreign object trapped inside the sealed container.

First claim

The invention claimed is:

1. A gas-insulated electric apparatus, comprising:
a sealed container made of metal;
a high-voltage conductor, housed within the sealed container, to receive voltage;
an insulating support member to insulate the high-voltage conductor from the sealed container and support the high-voltage conductor to the sealed container; and
a nonlinear-resistance film covering at least a portion of an inner surface of the sealed container, the portion being on a lower side of the inner surface with respect to the high-voltage conductor,
wherein the nonlinear-resistance film is formed by particles of a nonlinear-resistance material and an insulating material, the particles of the nonlinear-resistance material being dispersed in the insulating material, and
the particles of the nonlinear-resistance material are placed in the insulating material such that a spacing between neighboring particles of the nonlinear-resistance material is smaller than a size of a conductive foreign object so that one or more of the particles of the nonlinear-resistance material is in constant contact with the conductive foreign object trapped inside the sealed container.

2. The gas-insulated electric apparatus according to claim 1 , wherein, where a particle size of the nonlinear-resistance material is d, a size of the conductive foreign object trapped inside the sealed container is D, and a filling rate of the particles of the nonlinear-resistance material in the insulating material is Z, the nonlinear-resistance film is configured by using the nonlinear-resistance material having the particle size d and the filling rate Z that satisfy

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3. The gas-insulated electric apparatus according to claim 2 , wherein the size D of the conductive foreign object is set to 0.2 mm for the nonlinear-resistance film.

4. The gas-insulated electric apparatus according to claim 1 , wherein the nonlinear-resistance film includes particles of the nonlinear-resistance material that are dispersed in the insulating material, and
specific gravity of the nonlinear-resistance material is smaller than specific gravity of the insulating material.

5. The gas-insulated electric apparatus according to claim 1 , wherein the nonlinear-resistance film is formed by particles of a nonlinear-resistance material and an insulating material, the particles of the nonlinear-resistance material being dispersed in the insulating material, and
an average film thickness of the nonlinear-resistance film is smaller than a particle size of the nonlinear-resistance material.

6. The gas-insulated electric apparatus according to claim 1 , wherein a particle-size distribution of particles that are included in the nonlinear-resistance film and have a nonlinear characteristic has a peak at one particle size.

7. The gas-insulated electric apparatus according to claim 1 , wherein a time constant that is yielded when resistivity of the nonlinear-resistance film takes a minimum value is smaller than a discharge delay time.

8. The gas-insulated electric apparatus according to claim 1 , further comprising an insulator film placed between the nonlinear-resistance film and the sealed container.

9. The gas-insulated electric apparatus according to claim 1 , wherein the insulating material is made of resin.

10. The gas-insulated electric apparatus according to claim 9 , wherein surface roughness of the nonlinear-resistance film is equal to or smaller than a particle size of the nonlinear-resistance material and is greater than surface roughness of a film made by using only the insulating material.

11. A manufacturing method of a gas-insulated electric apparatus, the method comprising:
a step of forming a nonlinear-resistance film on an inner portion of a sealed container made of metal, the nonlinear-resistance film including an insulating material and a nonlinear-resistance material; and
a step of polishing a surface of the nonlinear-resistance film so as to reveal the nonlinear-resistance material.

Assignees

• Mitsubishi Electric Corp

Inventors

• Yoshimura Manabu
• Kawano Ryoko
• Kainaga Soichiro
• Yokomura Nobuo
• Sato Satoru
• Nakauchi Shinichiro

Classifications

• H02G5/065 Primary

  Particle traps (gettering in vacuum switches H01H33/6683; in discharge or vacuum tubes H01J7/18, H01J19/70) · CPC title

• H01B17/62

  Insulating-layers or insulating-films on metal bodies · CPC title

• H02B13/045

  Details of casing, e.g. gas tightness · CPC title

• H01H9/02

  Bases, casings, or covers (accommodating more than one switch or a switch and another electrical component H02B1/26) · CPC title

• H01H9/48

  Means for preventing discharge to non-current-carrying parts, e.g. using corona ring · CPC title