Hitachi, Ltd.

Japan Ae Power Systems Corporation

Kyuji Yaginuma

Hiroshi Suzuyama

Masatomo Ohno

Takehiro Kikuchi

Rei Henmi

Shigeru Fujiya

Kenji Annou

Taeyong Shin

Operating shaftallows disconnecting switch-side and earthing switch-side moving contactsandto linearly reciprocate with the rotation of operating shaft. Operating shafthas two-hole leverallow an arc motion. Each one end of two curved linksa andb is connected to two-hole leverand the other end of two curved linksandis respectively connected to the disconnecting switch-side moving contact or the earthing switch-side moving contact. When the two connecting points are axisymmetric with respect to the bisector, both the disconnecting switch and the earthing switch are in an open state; when two-hole levermoves at a predetermined angle to the disconnecting switch-side, the disconnecting switch is in a closed state; and when two-hole levermoves at a predetermined angle to the earthing switch-side, the earthing switch is in a closed state.

Disconnecting switch with earthing switch

Bus containerof cylindrical shape is filled with insulating gas and main circuit conductoris housed with bus containerin taut condition. Bus containerhas flange. Current transformer containeris installed adjacently to bus container. Current transformer containerincludes inner cylinderand outer sealing member. On the periphery of inner cylinder, three current transformersare provided interposing insulative cushioning material. Other longitudinal end of inner cylinderand bus containerare arranged so that insulation gapis formed in between. Between inner cylinderand outer sealing memberon insulation gapside, varistorof which resistance varies depending on a applied voltage is electrically connected through bonding conductor. Varistorturns into a conducting state when a surge voltage over a predetermined intensity is applied.

Gas insulated switchgear

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

An instrument current transformer for a main power cable which is composed of three power cables for three phases disposed in a power cable laying hole and three current transformer coils for the three phases, each of the three current transformer coils surrounding a corresponding one of the three power cables, the instrument current transformer including: a plurality of upper circumferential installation unit members disposed near an end portion of the power cable laying hole along circumference sides of an opening portion of the power cable laying hole, each of the upper circumferential installation members being provided with at least one securing portion extending in a radial direction and the upper circumferential installation unit members being secured to the end portion of the power cable laying hole via respective at least one securing portions; three axial installation members for the three phases, each extending along corresponding ones of the three power cables, first ends of the axial installation members being connected to the upper circumferential installation unit members and the three current transformer coils for the three phases being supported by corresponding ones of the three axial installation members; and a plurality of lower circumferential installation unit members having substantially a same configuration as corresponding ones of the upper circumferential installation unit members, the lower circumferential installation unit members being connected to second ends of the axial installation members opposite from the first ends.

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Hitachi, Japan

Kyuji Yaginuma