Hitachi, Ltd.

Hitachi Electric Systems Co., Ltd.

Other

Noriaki Munakata

Yukio Kurosawa

Haruo Honda

Shigetoshi Oouchi

Masaki Shinohara

Masato Suzuki

Akira Suzuki

Manabu Takamoto

Yoshihiko Matsuda

Naoki Kawamura

Naoyuki Yamamoto

Manaba Takamoto

Nobuyuki Takeuchi

Osamu Tsuji

Noaki Kawamura

A commutation type DC breaker comprising a main switch inserted in series into a main circuit for connecting a DC source and a load, a commutation capacitor, a reactor, and a commutation switch for supplying charges stored in the commutation capacitor to the main switch in an opposite direction to a main circuit current, producing a current zero point, thereby breaking the main switch,

Commutation type DC breaker

A power use circuit breaker includes an arc generating switching unit which adds an electrical resistance in a circuit during current interruption to attenuate a current to be interrupted, a vacuum bulb which is electrically connected in series with the arc generating switching unit and interrupts the attenuated current and a current conducting switching unit connected in parallel with the series circuit of the vacuum bulb and the arc generating switching unit. For current conduction the current conducting switching unit is closed after the vacuum bulb and the arc generating switching unit are closed, and for current interruption after opening the current conducting switching unit, the vacuum bulb and the arc generating switching unit are opened.

Power use circuit breaker and electrical circuit arrangement for electric power generation plant

A gas insulated circuit breaker includes a closed tank filled with an insulation gas, one pair of separable contacts disposed in the closed tank, a supporting frame supporting the closed tank, an opening spring for performing an opening operation of the pair of contacts, a closing spring for performing a closing operation of the pair of contacts, and an actuating mechanism box accommodating an opening coil which is adapted to receive a circuit opening command for the contacts, a closing coil which is adapted to receive a circuit closing command for the contacts and an actuating mechanism for rendering the opening spring and the closing spring operative in response to an activation of the opening coil and the closing coil. A first spring casing accommodates the opening spring and is secured on the closed tank, and a second spring casing accommodates the closing spring and is secured on the supporting frame.

Gas insulated circuit breaker

Growing community of inventors

Juo-machi, Japan

Noriaki Munakata