Hitachi, Ltd.

Satoshi Miwada

Manabu Takamoto

Toyokazu Tanaka

Noriyuki Tetsu

Sadao Waizumi

Seizo Nakano

Tohru Tsubaki

Naoki Amano

Shigetaka Takeuchi

Haruji Nakano

Toshihide Mitomo

Yukio Kamura

A high voltage power receiving and transforming apparatus for consumer demands receiving power from two lines and supplying the power to respective transformers through instrument potential and current transformers. First circuit breakers at a primary side of the transformers, are arranged at both sides of the instrument potential and current transformers, second circuit breakers, at a receiving side, are arranged at both sides of said first circuit breakers. The circuit breakers and receiving portion connecting portion to the transformers, and the instrument potential and current transformer are connected by a duct line connection portion at a backside of the circuit breakers.

Receiving and transforming apparatus

A power receiving and transforming system comprising a gas insulated switchgear, with transformers being disposed adjacent the gas insulated switchgear and metal enclosed switchgear sections disposed on opposite sides of the transformers with respect to the gas insulated switchgear. The metal enclosed switchgear sections have metal enclosed switchgear units juxtaposed in a direction in which the gas insulated switchgear and the transformers are juxtaposed. The metal enclosed sections are located opposite to each other in a direction perpendicular to the direction of the juxtaposition. Therefore, the metal enclosed switchgear sections can be arranged so as to have a width equal to a width of the gas insulated switchgear and the width will not change even if the number of feeders in the metal enclosed switchgear sections is increased thereby enabling the entire power receiving and transforming system to be regularly installed at a site.

Customer's power receiving and transforming system

A gas insulated switchgear apparatus, in particular a phase-separated, double main bus-type switchgear apparatus, in which first and second phase-separated main buses are interchangeable and are arranged in horizontal planes in such a manner as to reduce the space needed for the apparatus.

Gas-insulated switchgear apparatus

A gas-insulated switchgear apparatus including a three-phase circuit breaker, a three-phase disconnecting switch and a cable head, with the disconnecting switch and the cable head being accommodated in a cable head housing. To minimize the size of the disconnecting switch, movable insulators, connected to movable conductors, and stationary insulators, supporting connecting conductors, are arranged so that the movable and stationary insulators form triangles disposed substantially in the same plane with the respective triangles being inverted in relation to each other.

A ground test switch comprises a terminal plate electrically connected to a movable contact member but electrically insulated from a closed vessel enclosing a high-voltage conductor, a grounding conductor disconnectably electrically connecting the terminal plate to a member maintained at ground potential, and a locking device locking the movable contact member against movement when the grounding conductor is detached from the connecting position. The operator may forget to mount the grounding conductor in the switch again after a ground test. Such a trouble can be readily detected because the movable contact member is locked against movement.

Growing community of inventors

Ibaraki, Japan

Satoshi Miwada