Hitachi, Ltd.

Masatomo Ohno

Hideo Kawamoto

Akira Suzuki

Manabu Takamoto

Hiromichi Hokutou

Tetsuo Fukuchi

Hideaki Fukuda

Masanori Tsukushi

Youichi Ohshita

Kunio Hirasawa

Hitoshi Yamada

Shunji Tokuyama

Kyuji Yaginuma

Hiroshi Yoshimoto

Kenji Annou

Yasuhiro Igarashi

Atsuji Watanabe

Hiromichi Hokuto

Tetsuo Kanazawa

A storage device for storing data sent from a host apparatus comprises a plurality of processors sending to a cache memory controller an access instruction relating to transmission of the data, based on an access request relating to the transmission of the data, the access request being sent from the host apparatus; and an access instruction sending unit exclusively sending to the cache memory the access instruction sent from the plurality of processors, wherein the access instruction sending unit includes a plurality of storage units for storing an access instruction which requires a response, and wherein when the access instruction which requires a response is stored in all of the storage units, the access instruction sending unit sends only an access instruction which requires a response to the cache memory controller.

Storage device and access instruction sending method

In a gas-insulated transmission line for transmitting electric power between the substations, a bus change-over disconnecting switch for connection to a reserve circuit is provided at a portion where the gas-insulated transmission line is connected to a gas-insulated switchgear in order to improve reliability, and a first circuit and a second circuit are connected to the reserve circuit by using the change-over disconnecting switch. Therefore, even if grounding fault occurs on the two circuits at worst, transmission of electric power is reliably maintained without causing power failure.

Gas-insulated transmission line having reserve circuit for recovering

A circuit breaker includes a tank grounded and filled with an insulating gas, a first electrical series-connected section having a main conductor and a main breaking section, and a second electrical series-connected section having a resistor and an advance closing contact device. The first electrical series-connected section is coupled electrically in parallel to the second electrical series-connected section. The fixed contact side of the main breaking section is supported by an insulating cylinder and the fixed contact side of the advance closing contact device is supported by an insulating plate from the fixed contact side of the main breaking section. A breaking unit, chiefly composed of the main breaking section and the advance closing contact device, is supported by insulating cylinders. A resistor unit is supported by an insulating cylinder. The assembly of each of the units can be performed completely outside the tank, thereby eliminating the need for performing any adjustment type of work within the tank.

Gas insulated high voltage circuit breaker including tulip contact

A gas circuit breaker 40 automatically interrupts a fault current such as ground fault current flowing through a conductor 61 of a bus line 60. A high speed grounding switch 10 performs a higher grounding and its releasing operation than the open and close operation of the gas circuit breaker 40 during the open and close operation thereof and guarantees the current interrupting performance and the inter-electrode insulation performance of the gas circuit breaker 40. In association with the electrode arrangement of a disconnecting switch 20, bus lines 60A and 60B are disposed in horizontal direction, a stationary electrode 13 of the high speed grounding switch 10 is provided at the constitutional unit 21 of the disconnecting switch 20 so as to locate on the same straight line as the central axis of the bus line and the movable electrode 11 at the ground side is closed along the same straight line as the central axis of the bus line. The stationary electrode 13 can be provided at a bent corner or a branching portion while locating the stationary electrode 13 and the movable electrode 11 on the same straight line as the center axis of the bus line. Thereby, durability of a gas insulated switch gear device provided with a high speed grounding switch is improved while reducing the entire size and the production cost thereof.

Gas insulated switch gear device

A gas circuit breaker having a resistance circuit breaking portion connected in parallel with a main circuit breaking portion includes a main circuit breaking portion actuating mechanism and a resistance circuit breaking portion actuating mechanism. The resistance circuit breaking portion actuating mechanism is provided with a first delaying mechanism mechanically coupled to the main circuit breaking portion actuating mechanism, and a second delaying mechanism, independent from the first delaying mechanism, which is operated by an electrical command signal relating to either a making or an interrupting electrical signal to the main circuit breaking portion actuating mechanism. The otherwise possible thermal break-down of a resistor connected in series with the resistance circuit breaking portion is prevented.

Gas insulated switchgear insertion resistor and main contacts operating

A first puffer chamber is formed by a puffer cylinder having a substantially cylindrical flange portion and a shaft portion, and a fixedly disposed piston. The piston is formed in a cylindrical shape sealed with respect to an external space, and is constituted to be accommodated in the flange portion of the puffer cylinder at the circuit breaking position of the circuit breaking unit. The internal space of the piston is constituted as a second puffer chamber which is designed to communicate with the first puffer chamber. The gas accumulated in the second puffer chamber is continuously blown out toward between the electrodes, thereby prolonging an effective interruptable arc time span without increasing the size of the circuit interrupting unit and operating unit.

Grounding switch gear device

A gas-filled circuit breaker includes a hermetically sealed tank formed by a surrounding wall filled with an insulating gas, at least one pair of contacts which are arranged in the inside of the surrounding wall, and a contact operating device for connecting the contacts to each other for conducting electricity therebetween and separating the contacts from each other for interrupting the electricity therebetween. The contact operating device includes a force generating device for generating a force for operating the contacts, and the contact operating device is arranged outside of the surrounding wall. A rotational shaft device is connected to the force generating device outside of the surrounding wall and extends from the outside of the surrounding wall to the inside thereof so that the force generated by the force generating device is transmitted through the surrounding wall to the inside thereof. A seal device is arranged between the surrounding wall and the rotational shaft device to maintain a hermetic seal therebetween, and at least two bearings rotatably support the rotational shaft device; and a connecting device for transmitting the force from the rotational shaft device to at least one of the contacts is moved in relation to another one of the contacts, wherein the connecting device is connected to the rotational shaft device between the bearings.

Operating mechanism for an inert gas filled circuit breaker

An operating device for a gas circuit breaker includes an operating piston reciprocably movable between a first position and a second position, with the operating piston dividing an internal space of the operating cylinder into a first chamber and a second chamber. An exhaust port in the operating cylinder communicates with the first chamber when the operating piston is disposed near the second position, and the exhaust port communicates with the second chamber when the operating piston is remote from the second position. High-pressure air is introduced into the first chamber at the time of the breaking operation. An exhaust valve device discharges the air from the first chamber when the air pressure within the first chamber decreases below a predetermined level. The exhaust valve device includes a valve element having a pressure-receiving portion receiving the air pressure from the first chamber. The pressure-receiving portion is positioned so as to be out of contact with the operating piston when the operating piston is disposed at the first position.

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Hitachi, Japan

Masatomo Ohno