Hitachi, Ltd.

Japan Ae Power Systems Corporation

Hitachi Industrial Equipment Systems Co., Ltd.

Tomoaki Utsumi

Takashi Sato

Fumihiro Endo

Kenji Tsuchiya

Ayumu Morita

Masato Kobayashi

Kazuo Kobayashi

Tatsuro Kato

Takashi Shirone

Kazuhiro Saito

Tokio Yamagiwa

Toshio Ishikawa

Kazuhiro Satou

Shuzo Iwaasa

Makoto Yano

Goro Daimon

Miki Yamazaki

Toshiaki Rokunohe

Junichi Katagiri

Youichi Ohshita

Shuichi Kikukawa

Jun Nukaga

Masato Yabu

Daisuke Sugai

Takashi Omori

Yoshitaka Yagihashi

Shunji Ito

Yoshinori Tagawa

Hiroshi Yoshimoto

Takafumi Hosono

Takuya Sugawara

An object is to provide a switching unit or switching gear which enhances heat radiation performance and eliminates the need for an increase in unit size. In order to solve this problem the switching unit includes a switch and insulating resin located in a way to cover the periphery of the switch, in which the switch includes a fixed electrode, a movable electrode facing the fixed electrode and moving in an axial direction to contact or leave the fixed electrode, a bus side conductor connected to one of the electrodes and connected to a bus, and a load side conductor connected to the other electrode and connected to the load. The insulating resin has fins formed in a circumferential direction on the outer surface of the insulating resin and the distance between the periphery of the switch and the bottoms of the fins is almost constant in the circumferential direction.

Switching unit or switching gear

A switch unit includes a plurality of switches, which are linearly disposed. The movable electrode in one switch and the fixed electrode in another switch are electrically connected to each other.

Switch unit and switchgear

In order to improve cooling performance of a switch unit or switchgear equipped with the switch unit, the switch unit includes a switch having a movable electrode and a fixed electrode and is casted as one body with a resin, the resin is provided with resin fins, and the thickness of the resin fin is changed so that the resin fin has a thickness sloped in the longitudinal direction of the resin fin.

Switch unit and switchgear equipped therewith

A switchgear includes an earthing and disconnecting switch which linearly moves and is switchable to a disconnecting and an earthing positions, a vacuum valve which performs closing and breaking of a current in a vacuum container producing vacuum inside, and a solid insulator with which the earthing and disconnecting switch and the vacuum valve are covered, therein the earthing and disconnecting switch and the vacuum valve are electrically connected, and closing and breaking of a current is performed in the vacuum valve.

Switchgear and method for operating switchgear

A vacuum switchgear has a vacuum valve including a movable conductor connected to an insulating rod, and a fixed conductor connected to a bus bar or to a load cable, a vacuum chamber encasing the vacuum valve, an insulating envelope covering the vacuum chamber, the outer surface thereof being covered with an electro-conductive layer thereby to earth the envelope, and an insulating lid gas-tightly fitted to the insulating envelope. The lid has an insulating bushing through which an insulating rod penetrates, the insulating rod being connected to an operating mechanism, wherein the insulating rod except a portion exposed from the bushing is gas-tightly confined in insulating gas atmosphere formed between the insulating envelope and the insulating lid.

Vacuum switchgear

A reliable, compact vacuum switchgear is provided at an inexpensive cost. The vacuum switchgear comprises a switchhaving a fixed electrodeand a movable electrodeconnectable to and disconnectable from the fixed electrode, another switchhaving a fixed electrodeand a movable electrodeconnectable to and disconnectable from the fixed electrode, conductorsconnected to the fixed electrodesof the switches, earth switchesconnected to the conductors, a mold sectionformed by molding the conductorsand the earth switcheswith resin, and a vacuum containeraccommodating the switchesand disposed on the mold section

A main circuit switching unit and an isolator are accommodated in a vacuum container. A first conductor and a main circuit conductor are arranged to extend in and out of the vacuum container. A movable electrode of the main circuit switching unit is connected to the first conductor through a first flexible conductor, and a movable electrode of the isolator is connected to the main circuit conductor through a second flexible conductor. A shield is arranged around the first conductor and the main circuit conductor. Another shield is arranged around a connecting portion between the first flexible conductor and the movable electrode of the main circuit switching unit. A still another shield is arranged around the isolator. A further another shield is arranged around the second flexible conductor. These shields are secured to the vacuum container through insulating spacers. This arrangement instantly eliminates a dielectric breakdown phenomenon that occurs at electric field concentrated regions by the shields to prevent a dielectric breakdown caused by particulate foreign matters and thereby improve an insulation reliability of the devices.

In a gas-insulated switchgear tank in which an electric insulating characteristic is improved by a gas, and which has a vacuum circuit-breaker, a disconnecting switch, and a container in which container the vacuum circuit-breaker and the disconnecting switch are arranged and an inside of which container is adapted to be hermetically sealed and filled with the gas in such a manner that the vacuum circuit-breaker and the disconnecting switch are at least partially surrounded by the gas, the gas includes Nand O.

Gas-insulated switchgear tank

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushingsAs this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube

Gas insulating apparatus and method for locating fault point thereof

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushingsAs this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube 15.

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushings. As this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube

Gas insulated device and failure rating method

In a gas insulated electric apparatus having gas sections filled with insulating gas, a locating device determines a position of a gas section in which an insulation abnormality is detected, on the basis of a detection signal from sensors disposed in each of predetermined gas sections. At the same time a hindering degree diagnosing device diagnoses the degree and the kind of the insulation abnormality, by comparing a detection signal from the sensors with data stored in a data base. A valve control generates a valve control signal, responding to the locating device and the hindering degree diagnosing device, and in response to the valve control signal, a trip circuit generates a valve opening signal to open an electromagnetic valve disposed in a gas section in which an insulation abnormality is detected. An insulating gas injecting and evacuating device injects an insulating gas, different from the initial insulating gas with which the gas sections are filled beforehand, into the gas section for which the electromagnetic valve has been opened by the valve opening signal, or evacuates a predetermined amount of the insulating gas with which the gas sections are filled beforehand, so as to increase insulation strength.

Gas insulated electric apparatus

A gas insulated switchgear has a container which is filled with an insulating gas, a conductor disposed with the container, an insulator for supporting the conductor. An outer periphery of the insulator is made smooth so as to improve a dielectric strength of the device. The insulator is made of an organic substance base and an inorganic material filler added to the base. In order to improve the dielectric strength, the filler is atomised or the insulator is coated.

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Hitachi, Japan

Tomoaki Utsumi