Fuji Electric Co., Ltd.

Tadao Kitamura

Toshio Kobayashi

Mamoru Yamada

Hisaji Shinohara

Yukio Osawa

Yosikata Matsumura

Noboru Usui

An electrically insulating supporting structure for a high voltage electric apparatus having a high voltage charging part and a ground potential part, the structure being adapted to be disposed between the high voltage charging part apparatus and the ground potential part. The structure includes an organic insulating structure formed in a predetermined shape, and an inorganic insulating layer formed on a surface of the organic insulating structure and an intermediate layer consisting essentially of an organic and an inorganic powder.

Insulating supporting structure for high-voltage apparatus including

An improved vacuum valve including an insulating container and an arc shield held in the insulating container, wherein a protrusion is formed on either the outer cylindrical surface of the arc shield or on the inner surface of the container. A detecting electrode is set confronted with the outer surface of the insulating container with an air gap therebetween, and is grounded through a current sensor. The current sensor detects a discharge current which is induced through the protrusion when the degree of vacuum of the vacuum valve is reduced, to output a detection signal. In response to the detection signal, a signal processing unit outputs an alarm signal indicating the reduction in the degree of vacuum of the vacuum valve. Thus, while the vacuum valve is in operation, its vacuum reduction can be positively detected with the vacuum valve maintained unchanged in reliability.

Method and apparatus for detecting a reduction in the degree of vacuum

A gas-insulated switchgear in which a vacuum switch main contact assembly constituted by a fixed contact element and a movable contact element is enclosed in a vacuum tank. The vacuum switch has a movable terminal fixed at its one end to the movable contact element and is led out from the vacuum tank through a bellows. The vacuum switch is enclosed in a gas tank filled with an insulating gas having gas pressure not less than the atmospheric pressure. The main contact assembly of the vacuum switch is operated so as to perform electrical connection and disconnection functions, through a transmission mechanism, by a driver provided outside of the gas tank. A driving rod transmits an operating force of the driver to the movable terminal of the vacuum switch. The driving rod is led out from the gas tank through another bellows mounted to the gas tank.

Growing community of inventors

Kawasaki, Japan

Tadao Kitamura