Hitachi, Ltd.

Minoru Sakaguchi

Hiroshi Suzuyama

Syunji Itou

Yoshirou Suzuki

Kazuaki Oishi

Osamu Mikami

Kenji Tsuchiya

Seizo Nakano

Yoshiro Suzuki

Tuneo Kishi

Takehiro Kikuchi

Takanobu Aoyama

Masahiro Takahoshi

Hitoshi Kayaba

Hiromichi Hokuto

Masatomo Kobayashi

Hideaki Satou

Susumu Takeuti

Koji Yokoyama

Kenji Akita

Yoichi Ohshita

Sheaths accommodate a high-voltage conductor in their insides, and annular grooves are respectively provided in flanges of the sheaths outwardly of inserting holes for bolts which are disposed in annular form. Annular grooves are provided in an insulating spacer inwardly of the inserting holes for the bolts. O-rings are respectively provided in the annular grooves. An annular groove is also formed in a flange connection face so as to have bolt inserting holes at its bottom. After the flanges have been fixed by using the bolts, nuts and sealing washers, a liquid packing is injected into the flange connection face groove through a liquid packing injection opening which communicates with the groove. Since a sealing element is disposed outwardly of the bolt holes, it is possible to prevent penetration of rainwater or the like into the gaps between connected flanges with airtightness being retained. It is also possible to readily inject the liquid packing into the gaps between the flanges. By using sealing washers, it is possible to more readily inject the liquid packing into the gaps between the flanges.

Sealed container and method for assembling it

A gas-insulated switchgear in which a washer 5 is electrically connected with a tank 1 by a conductive material 12 having a high resistivity at a position where the tank 1 and a tank 2 are joined through an insulator 13 of the gas-insulated switchgear. In view of the structure of the switchgear, the reliability is improved, the structure is simplified, the number of parts is decreased, and the profitability is improved because a steep surge is not theoretically induced for a steep surge induced when turning on/off each unit at an electrically insulated position of a joint between tanks through an insulator of a gas-insulated switchgear for an SF.sub.6 gas-insulated closed-type station.

Gas-insulated switchgear with improved insulation joint

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

The present invention provides a three-phase lumped together gas insulated switchgear, which is small-sized and simply constructed, including main busbar conductors and disconnectors connected to the main busbar conductors. In the gas insulated switchgear, phases of the main busbar conductors are respectively disposed on the vertexes of a triangle. Further, the axes of the disconnectors and disconnector movable side conductors, both of which correspond to three phases, are arranged between one phase of the main busbar conductor and the other two phases of the main busbar conductors so that the axes of the disconnectors for the busbars become parallel with each other. Furthermore, the movable side conductors are connected to the main busbar conductors. Because of the above construction, a circuit breaker and the busbars can be linked within the shortest possible distance to the disconnectors arranged between the circuit breaker and the busbars.

Gas insulated switchgear

A gas-insulated switchgear comprises a sealed enclosure filled with an electrically insulating gas, isolators of three phases for making/breaking a main circuit, and earthing switches of the three phases for grounding the main circuit. The isolators and the earthing switches are disposed in the sealed enclosure, with the isolator of each phase including oppositely disposed stationary and movable side contacts, and a movable contact for turning on or off electrical connection between them. The earthing switch of each phase includes an earth stationary contact connected to one of the movable side conductors and an earth movable contact for connection with or disconnection from the earth stationary contact. The components of the isolators of the three phases and the components of the earthing switches of the three phases are respectively situated on two virtual planes, which are adjacent to each other and disposed substantially along a longitudinal direction of the sealed enclosure.

Three-phase package-type gas-insulated switch gear having isolators

In a gas insulated switchgear equipment device, at least one gas insulated main bus bar is arranged on an attachment surface and a plurality of feeder units each having one end connected to the gas insulated main bus bar and the other end connected to an insulating terminal are arranged along a longitudinal direction of the gas insulated main bus bar, thereby constituting a substation equipment device. A gas insulated bus-section-unit is arranged on a portion of the gas insulated main bus bar and has at least a circuit breaker and disconnecting switches connected to both ends of the circuit breaker, and one end of the bus-section-unit is connected to the corresponding gas insulated main bus bar and the other end of the bus-section-unit is provided with at least one external lead-out device connectable to an external connecting device. With this arrangement, by the use of the bus-section-unit arranged on the portion of the gas insulated main bus bar, the substation equipment separated or increased can be easily interconnected or renewed.

Gas insulated switchgear with bus-section-unit circuit breaker and

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.

Gas insulated switchgear apparatus

An apparatus for operating switches including a driving shaft having an operation lever portion supporting one end of a spring mechanism, with the driving shaft being separated from an operation shaft associated with a switch. A driving lever fixed to the driving shaft is connected to a main lever with a recess fixed to the operation shaft. An angle formed by central axes of these levers is set to an angle slightly exceeding 90.degree. when a switch opening or closing operation is completed. Members for regulating the opening and closing positions of the switch are provided at positions opposed to the driving lever. By setting the angle to the above value, in a side where the angle exceeds 90.degree., an operating force transmitted from the driving lever to the main lever acts in a direction opposite to a direction to which the operating force acts until the angle reaches 90.degree., thus cancelling operating inertia energy and residual energy in the driving lever.

Apparatus for disconnecting a switch of a high voltage electric circuit

Gas-insulated switchgear

A novel connecting system for a gas-insulated switchgear apparatus is disclosed. An electrical device is installed on a foundation adjacent to gas-insulated devices of respective phases in a predetermined indoor installation space, and bushing are arranged on the other side of the electrical device. The gas-insulated devices are connected to the bushings by gas-insulated bus bars respectively. Pits for gas-insulated bus bars are formed independently through the foundation of the electrical device, and a transport unit is laid in each of the pits. This transport unit is combined with a transfer unit mounted on each of the gas-insulated bus bars to transport the gas-insulated bus bars of respective phases to facilitate the laying thereof. The gas-insulated bus bars are thus laid in a short distance without reducing the strength of the foundation of the electrical device while at the same time facilitating the laying of the gas-insulated bus bars.

Connecting system for gas-insulated switchgear apparatus

An earthing switch for gas-insulated switchgear apparatus is disclosed, in which conductor within an enclosure is provided with a stationary contact, and a moving contact is movably provided to connect with and disconnect from the stationary contact by an operating mechanism within an operating mechanism case which is mounted on a branch tube of the enclosure interposing an insulating plate therebetween. For connecting the moving contact to the enclosure electrically, a plurality of earthing bars are employed, and further, directions of electromagnetic forces generated between the moving contact and individual earthing bars are considered in the connection of the earthing bars. By virtue of the connection of the plurality of earthing bars, the influence of the electromagnetic forces acting on the moving contact can be reduced to a great extent.

Earthing switch for gas-insulated switchgear apparatus

A three-phase combined type gas insulated bus is disclosed which comprises at least one eddy current conductor for passing the eddy current caused secondarily by the current flowing in high voltage conductors, thus solving the problem of a newly-found phenomenon that the temperature of a sealed casing increases by the flow of the eddy current. This eddy current conductor is made of such a material of good electrical conductivity as aluminum or copper. Even in the case where the sealed casing is reduced in diameter to such an extent as to pose a problem of temperature increase by the eddy current flow, the eddy current is reduced or completely eliminated in the best case, so that the sealed casing can be made of a low cost soft steel.

Three-phase combined type gas insulated electrical 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.

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Hitachi, Japan

Minoru Sakaguchi