Hitachi, Ltd.

Syunji Itou

Minoru Sakaguchi

Hiroshi Suzuyama

Yoshiro Suzuki

Haruo Honda

Tohru Tsubaki

Takahide Seki

Masahiro Takahoshi

Hitoshi Kayaba

A gas insulated switchgear device includes a pair of main bus lines arranged in parallel; a pair of auxiliary bus lines arranged in parallel; three sets of circuit breakers each including at both ends thereof respective disconnecting switches, the three sets of circuit breakers being electrically connected in series between the pair of main bus lines via the pair of auxiliary bus lines; and a cable head provided at junction points between the disconnecting switches belonging to the respective adjacent circuit breakers. The pair of main bus lines and the pair of auxiliary bus lines are arranged in parallel with each other over a substantially horizontal plane near their installation plane, and the three sets of circuit breakers are vertical type circuit breakers and are disposed at one side of the pair of main bus lines and of the pair of auxiliary bus lines along their axial direction.

Gas insulated switchgear device

A gas-blast load-break switch comprises a pressure storage chamber for storing pressure of arc-extinguishing gas with arc energy generated by the disconnection between contacts, and a suction chamber including a piston which is moved in connection with the cut-off movement of the movable contact. A gas flowing device is provided such that the pressure raised by the arc energy is stored in the pressure storage chamber before communicating the pressure storage chamber and the suction chamber and a gas chamber formed on the opposite side of the piston from the suction chamber. The volume of the gas chamber is greater than that of the pressure storage chamber and the suction chamber, and the distance of piston movement in the suction chamber is longer than the contact length when the movable contact is thrown into the fixed contact.

Gas-blast load-break switch

A gas-insulated switchgear apparatus has a sealed container including a cylinder body having a substantially circular cross-section and end plates closing the end portions of the cylinder body. The sealed container accommodates breaker portions situated so as to work opening and closing actions in the vertical direction and current transformers. Main bus bars located on the side of the sealed container are connected with the breaker portions located inside of the sealed container through openings formed in the end plates. A line side terminal portion located on the side of the sealed container is connected with the breaker portions locating inside of the sealed container through openings formed in the end plates.

Gas-insulated switchgear apparatus

In a gas-insulated switchgear apparatus, breakers of three phases are contained in a barrel-type sealed enclosure having an insulating gas sealed therein. At least one terminal of each of the breakers is connected to each of a plurality of main buses arranged on the outside of the sealed enclosure, and a common casing is attached to one side of the sealed enclosure to extend in the height direction thereof. The ground housing of each of the main buses is connected through an insulating spacer to the common casing. Connecting conductors for connecting the terminals of the breakers with the bus conductors of the main buses are led into the casing or a plurality of current transformers are arranged in the casing. By so doing, the sealed enclosure is reduced to a size having a sectional area sufficient for juxtaposition of the breakers of three phases and thus the whole gas-insulated switchgear apparatus is made more compact and smaller. Also, the connecting conductors and the current transformers are isolated from the breakers by arranging them inside the common casing and this has the effect of enhancing the insulation reliability and ensuring suitable arrangement of the current transformers.

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Hitachi, Japan

Syunji Itou