Hitachi, Ltd.

Other

The Chugoku Electric Power Co., Inc.

Hatachi Ltd

Seizo Nakano

Kazuaki Oishi

Shingo Shirakawa

Tuneo Kishi

Masaki Murashita

Seiichi Maruyama

Yutaka Kobayashi

Takeshi Takahashi

Koji Sasaki

Takashi Sato

Kouji Sasaki

Tohru Tsubaki

Takashi Satoh

Masayoshi Hashiura

Osamu Isshiki

Hideaki Kikuchi

Hiroshi Itoh

Koji Goto

Osamu Matsushima

Shinji Fukuda

Sadao Nakagawa

Katsuro Ota

Jun Ozawa

Kazuo Suzuki

Minoru Sakaguchi

Shigeo Shiono

Katsuji Shindo

Satoshi Miwada

Isao Nishida

Takehiro Kikuchi

Naoki Amano

Kouichi Nakano

Masao Hosokawa

Shigetaka Takeuchi

Yutaka Kitano

Michio Moriya

Akio Mizukoshi

Yoshi Akatsu

Yukinori Yamaoka

Eichi Okamoto

Masaoki Tamura

Sigetaka Takeuchi

Masatomo Sato

Kenji Kohara

Yukio Kamura

Syoetu Suda

Shouetu Suda

In a lightning protection system for a wind power generation installation, a conductor ring is provided on a wind mill vane and at a rotor casing incorporating a wind power generator a zinc oxide element is provided so as to face the conductor ring with a spark gap , thereby, if a lightning in winter season which causes to flow a large current for a long duration time hits the wind mill vane , the wind power generation installation is effectively protected.

Lightning protection system for wind power generation installation

A welded metal container for a sheath 1 or 1A of gas insulated switch gear comprises a trunk pipe 2, 21 and a branch pipes 3, 31, 32 welded to the trunk pipe 2,21 by arc welding A or laser beam welding LB and flanges welded to the each end portion of the trunk pipe 2, 21 and branch pipes 3, 31, 32 by the laser beam welding. After the arc welding A, the ends of trunk pipe 1, 21 and branch pipes 3, 31, 32 are machined precisely and flanges 4a, 4b, 4c, 4d, 4f and 4g are welded to the end portions of the trunk pipe 2, 21 and branch pipes 3, 31, 32.

Structure of metal container having trunk pipe and branch pipe, and

A method for manufacturing a welded metal container by first arc welding a branch pipe to a trunk pipe. The arc welding of the pipes together causes both of the pipes to be thermally deformed. The end surfaces of the pipes are then cut by a laser cutting or mechanical cutting process so that the ends of the trunk pipe are in parallel and perpendicular to the end of the branch pipe. Subsequently flanges are laser welded to the ends of the pipes without further thermally deforming the pipes. The metal container made by this process can be used as a sheath for a gas insulated switch gear.

A transmission line protection system arranged such that a leakage current detector is provided at an end of an insulating device such as an insulator connected at one end to a corresponding one of arms of a steel tower and connected at the other end to a transmission line of each phase, thereby detecting an arrester leakage current flowing in the transmission line of each phase, an output signal of the leakage current detector being led to a repeater through an optical fiber cable, an output of the repeater being transferred to a control/supervisory board in a substation through an optical fiber cable. In the control/supervisory board, preferably, a received digital signal which was converted from an analog signal at said leakage current detector is displayed on a cathode ray tube. In such an arrangement, it is possible to smoothly perform supervision of the status of the transmission lines without causing maloperations due to influences from the transmission lines.

Transmission line protection system

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.

Gas-insulated switchgear apparatus

A zinc oxide lightning protector, wherein end plates are mounted at the ends of an insulator and a zinc oxide element section is arranged between the cover plates. Support metal members are mounted on the cover plates between the zinc oxide element section and the insulator to support an insulation cylinder therebetween. A space is formed between at least an end of an insulation cylinder and a corresponding cover plate to absorb the expansion or contraction of the insulation cylinder due to temperature changes, thus preventing the insulation cylinder from deforming. The elements are eccentrically arranged against the insulation cylinder, to thereby cause the gas flow along peripheral direction so that the laminar flow is changed into a turbulent flow. Thus, the heat conduction is improved to improve the radiation characteristic of the zinc oxide element section.

Zinc oxide lightning protector

A plurality of breaking portions forming a vertically-disposed circuit breaker are connected in series and open and close the circuit within a gas-tight sealed enclosure. The enclosure is provided at its both sides with openings for connection of one and the other ends of the breaking portions, to which openings main bus bars and an insulated-led-out device are connected, respectively. The breaking portions each have a fixed contactor and a movable contactor, and the movable contactor is put into contact with or is separated from the fixed contactor by moving the movable contactor upward or downward under control of an operating device.

Gas-insulated switchgear equipment

An insulating gas-filled disconnecting switch comprises a metallic container filled hermetically with an insulation gas, and a movable electrode and a stationary electrode disposed within the metallic container and electrically insulated from the latter. Means for guiding an arc possibly produced between both electrodes upon separation of the movable electrode from the stationary electrode positively toward a center portion of an opposite end of the stationary electrode, to thereby prevent the arc propagation toward the stationary electrode from reaching the metallic container from the stationary electrode.

Gas-insulated disconnecting switch

A gas insulated power switch gear apparatus of a reduced height comprising gas insulated circuit breakers arranged horizontally and disconnecting switches operated vertically is disclosed. Each of the disconnecting switches includes a first sheath portion inserted into an interrupted point of a main bus bar and mechanically connected with the sheath of the main bus bar through an insulating spacer for defining a gas section, and a second sheath portion communicating with the first sheath portion and crossing and extending in the direction perpendicular to the first sheath portion. A collector electrically connected with the conductor of a feeding bus bar is arranged within the second sheath portion, and a movable contactor normally electrically connected with the collector is movable vertically. A fixed contactor electrically connected with the main bus bar conductor and engageable with the movable contactor is arranged within the first sheath portion.

Gas insulated power switch-gear apparatus

In an enclosed-type zinc-oxide surge arrester with a grounded tank filled with an insulating medium, and a non-linear resistor assemblage which is connected at one end to a high voltage conductor and at the other end to the ground potential portion within the grounded tank, two or more ring-like shield means such as shield rings are disposed on the high voltage conductor side of the non-linear resistor assemblage at given distances. The use of the ring-like shield means makes more uniform the voltages shared by the respective non-linear resistors. The ring-like shield means may be formed with the configuration and diameter, and the number of them used being properly selected.

Enclosed-type zinc-oxide surge arrester

In an enclosed-type switching device having at least a pair of electric contacts, a method for checking the contacts without visual inspection wherein with the contacts closed, the resistance value between outer terminals connected to the contacts is measured and compared with a reference resistance value, so that the result of comparison is used to determine the degree of damage of the contacts. Also disclosed is an auxiliary apparatus for use with an enclosed-type switching device to facilitate application of the above-mentioned method, especially when the switching device is equipped with a plurality of parallel-connected sequentially closed or opened contact pairs. The auxiliary apparatus is arranged to interrupt the sequential operation of the contact pairs so that the resistance is measured during the interruption of the operation.

Method for checking electric contacts of an enclosed-type switching

A gas insulated switch-gear apparatus having first and second base planes is disclosed. Arranged on the first and second base planes are feeder switching apparatus comprising gas filled circuit breakers and first and second gas insulated disconnecting switches at opposite sides of each of the gas filled circuit breakers. Gas insulated busbar devices are arranged to be horizontally spaced from the feeder switching apparatus. On the first and second base planes, the first gas insulated disconnecting switches are connected to the gas insulated busbar devices while the second gas insulated disconnecting switches are connected to bushings. Axial lines of the feeder switching apparatus along which the first and second gas insulated disconnecting switches are arranged traverse axial lines of the gas insulated busbar devices. The axial lines of the gas insulated busbar devices arranged on the first and second base planes lie in a common vertical plane containing the axial lines and lie in the base planes. A gas insulated connecting busbar device for interconnecting the gas insulated busbar devices arranged on the first and second base planes is arranged in the common vertical plane such that an axial line thereof traverses the axial lines of the gas insulated busbar devices.

Gas insulated switch-gear apparatus

Gas-insulated switchgear apparatus wherein a device providing a first disconnect gap and a second disconnect gap is located in a sheath filled with an insulating gas and kept at ground potential. The disconnect gaps providing device comprises a first movable contact and a second movable contact which are insulatedly supported by a support device with respect to the sheath. There is provided a device for individually actuating the movable contacts which device comprises a pair of insulated actuating rods disposed adjacent and extending parallel to the insulating support device.

A grounded tank type gas circuit breaker comprises a grounded tank filled with a dielectric gas and having an opening airtightly sealed by a detachable cap, a capacitor unit electrically and mechanically connected at one end to the inner wall surface of the cap, and interrupting means mounted in the tank and electrically connected to the other end of the capacitor unit.

Grounded tank type gas circuit breaker

A gas insulated switch-gear wherein power circuit breakers, disconnecting switches, earthing switches and the like constituting a power electric sub-station are enclosed in earthed metallic vessels and insulation therein is effected by means of insulated arc-suppressing gas is housed in a switching house, a bushing forming a terminal at the electric power line side is provided separately outside of the switching house, and said bushing located outside and gas insulated switch-gear is electrically connected by means of gas insulated bus bar, to thereby eliminate a wall bushing.

Growing community of inventors

Mito, Japan

Seizo Nakano