Gas circuit breaker

Patent metadata

Field	Value
Publication number	US-11222760-B2
Application number	US-202016941979-A
Country	US
Kind code	B2
Filing date	Jul 29, 2020
Priority date	Feb 2, 2018
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A gas circuit breaker of an embodiment includes a sealed container, a first contact part and a second contact part, an operation mechanism, an insulating nozzle, a pressure accumulator, and an electric field shield. The insulating nozzle is displaced in conjunction with the first contact part in a separation process of the first contact part and the second contact part. The insulating nozzle surrounds arc discharge generated between the first contact part and the second contact part. The electric field shield is attached to the insulating nozzle. The electric field shield has a floating potential during a period of at least part of the separation process. The electric field shield is electrically connected to the second contact part such that the electric field shield has the same potential in a completely open electrode state in which separation between the first contact part and the second contact part is terminated.

First claim

What is claimed is:

1. A gas circuit breaker comprising:
a sealed container filled with an arc-extinguishing gas;
a first contact part and a second contact part provided to come into contact with each other and be separated from each other in the sealed container in a predetermined direction and separated from each other in an open electrode state while coming into contact with each other in a closed electrode state;
an operation mechanism connected to the first contact part and configured to separate the first contact part and the second contact part from the closed electrode state to the open electrode state;
an insulating nozzle formed in a tubular shape and configured to surround arc discharge generated between the first contact part and the second contact part in the open electrode state while being displaced in conjunction with the first contact part in a separation process of the first contact part and the second contact part;
a pressure accumulator configured to discharge the arc-extinguishing gas to a flow path in the insulating nozzle to perform blasting with respect to the arc discharge while accumulating a pressure of the arc-extinguishing gas; and
an electric field shield attached to the insulating nozzle, having a floating potential in a period of at least part of the separation process and electrically connected to the second contact part such that the electric field shield has the same potential in a completely open electrode state in which separation between the first contact part and the second contact part is terminated.

2. The gas circuit breaker according to claim 1 , wherein the second contact part comprises a conduction contact formed in a tubular shape extending in the predetermined direction and configured to come into contact with the first contact part in the closed electrode state, and
the electric field shield comes into contact with the conduction contact in the completely open electrode state.

3. The gas circuit breaker according to claim 1 , wherein the electric field shield has the same potential as that of the second contact part after half a period or more with respect to a commercial frequency has elapsed after a time when the first contact part and the second contact part have been separated from each other in the separation process.

4. The gas circuit breaker according to claim 1 , wherein the electric field shield does not come into contact with the second contact part until half a period or more of the commercial frequency elapses from a time when the first contact part and the second contact part are separated from each other in the separation process.

5. The gas circuit breaker according to claim 1 , wherein the electric field shield has the same potential as that of the second contact part in the closed electrode state.

6. The gas circuit breaker according to claim 1 , wherein the second contact part comprises:
a conduction contact formed in a tubular shape extending in the predetermined direction; and
an arc contact disposed inside the conduction contact and extending in the predetermined direction,
wherein the conduction contact and the arc contact each have a tip disposed in a direction in which the first contact part undergoes separation when seen from the second contact part in the predetermined direction, and
the electric field shield is disposed between the tip of the conduction contact and the tip of the arc contact in the completely open electrode state.

7. The gas circuit breaker according to claim 1 , wherein the second contact part comprises:
a conduction contact formed in a tubular shape extending in the predetermined direction; and
an arc contact disposed inside the conduction contact and extending in the predetermined direction,
wherein the conduction contact and the arc contact each have a tip disposed in a direction in which the first contact part is separated when seen in the second contact part in the predetermined direction, and
the electric field shield is disposed between the tip of the conduction contact and the tip of the arc contact in a state in the middle of the separation process.

8. The gas circuit breaker according to claim 1 , wherein an insulating member is disposed on a surface of the electric field shield.

9. The gas circuit breaker according to claim 1 , wherein the arc-extinguishing gas is a material having a smaller global warming potential than that of sulfur hexafluoride.

10. The gas circuit breaker according to claim 1 , wherein the electric field shield is formed of a metal material containing at least magnesium.

Assignees

• Toshiba Kk
• Toshiba Energy Systems & Solutions Corp

Inventors

• Majima Amane
• Inoue Tooru
• Uchii Toshiyuki
• Kato Norimitsu
• Shimamura Akira
• Yasuoka Takanori
• Tanaka Tsutomu
• Mori Tadashi

Classifications

• H01H33/04

  Means for extinguishing or preventing arc between current-carrying parts · CPC title

• H01H33/7069

  characterised by special dielectric or insulating properties or by special electric or magnetic field control properties (H01H33/7023 - H01H33/7061 take precedence) · CPC title

• H01H33/91

  the arc-extinguishing fluid being air or gas · CPC title

• H01H33/7023 Primary

  characterised by an insulating tubular gas flow enhancing nozzle (H01H33/7038 takes precedence) · CPC title

• H01H33/74

  wherein the break is in gas (in air at atmospheric pressure H01H33/73) · CPC title