Hitachi, Ltd.

Kunio Hirasawa

Masanori Tsukushi

Yukio Kurosawa

Yoshio Yoshioka

Tadashi Sato

Katsuichi Kashimura

Takeshi Takahashi

Osamu Koyanagi

Youichi Ohshita

Yoshimi Hakamata

Yasunori Ohno

Minori Satoh

Kenji Tsuchiya

Hideo Kawamoto

Tokio Yamagiwa

Fumihiro Endo

Hiroshi Arita

Hiroshi Suzuki

Mikio Sato

Isao Takahashi

Junzo Kawakami

Akio Nishikawa

Akira Hashimoto

Mitsuyasu Kido

Manabu Takamoto

Masatomo Ohno

Goro Daimon

Motoo Yamaguchi

Keiji Arimatsu

Tomoe Kurosawa

Tomio Chiba

Shunji Tokuyama

Ken-ichi Natsui

Masao Hosokawa

Kastuichi Kashimura

Yoshiaki Matsui

Hiromichi Hokuto

Youichi Oshita

Yuuichirou Yamane

Isamu Sone

Hiroshi Chida

Shunji Sato

Kooji Suzuki

Nobuya Sekimoto

A circuit breaker includes a tank grounded and filled with an insulating gas, a first electrical series-connected section having a main conductor and a main breaking section, and a second electrical series-connected section having a resistor and an advance closing contact device. The first electrical series-connected section is coupled electrically in parallel to the second electrical series-connected section. The fixed contact side of the main breaking section is supported by an insulating cylinder and the fixed contact side of the advance closing contact device is supported by an insulating plate from the fixed contact side of the main breaking section. A breaking unit, chiefly composed of the main breaking section and the advance closing contact device, is supported by insulating cylinders. A resistor unit is supported by an insulating cylinder. The assembly of each of the units can be performed completely outside the tank, thereby eliminating the need for performing any adjustment type of work within the tank.

Gas insulated high voltage circuit breaker including tulip contact

Breaking poles (1) and (2) are respectively secured to respective conductor bodies (4) and (5) and electrically connected thereto, and the conductor bodies (4) and (5) are fixedly secured and connected to each other by an interpole insulating support body (3). Interpole capacitors (7) are accommodated in the respective side walls of the interpole insulating support body (3). These parts for the breaking portion are accommodated within a grounded metal container (19) together with insulating gas and are secured to an operating box (18) via an insulating support body (17). The breaking poles (1) and (2) are designed to be transmitted an actuating force from the operating box (18) via an actuating insulation rod (not shown) and perform a breaking/making operation.

Gas insulated circuit breaker

An apparatus for controlling a switching device provided for breaking or closing a power line connecting a power source to a load in an electric power system includes a switching timing control unit for controlling the timing to apply a breaking signal to said switching device in response to a breaking signal externally applied thereto so that the contacts of said switching device are opened during a period of time when the current flowing through said power line first reaches its peak value from a zero value and for controlling the timing of applying a closing signal to said switching device in response to a closing command preferably externally applied thereto so that the contacts of said switching device are closed when the voltage of said power source becomes a predetermined value depending upon whether said load is capacitive or inductive, and an operating unit for opening and closing said contacts of said switching device in response to said breaking and closing signals, respectively.

Apparatus for controlling opening and closing timings of a switching

A switching mechanism for use e.g. in a circuit breaker of an underground electric substation has a movable rod which causes opening and closing of an electrical contact and a hydraulic operating system. The hydraulic operating system uses a hydraulic fluid which has a high flammability temperature or is incombustible. Thus, even if such fluid leaks from the hydraulic operating system, the risk of fire or explosion is minimized. The hydraulic operating system may have a sealed tank for the fluid, preferably with a variable volume expansion chamber. In a further development, the hydraulic operating system and possibly parts of the movable rod, is enclosed in a casing which is sealed and is filled with a gas which does not support combustion therein. Thus, the risk of fire or explosion is further reduced. The casing may have a variable volume expansion chamber.

Switch mechanism

In order to control a voltage using e.g. a tap transformer, the difference .DELTA.V between the actual voltage and a reference voltage is obtained and integrated over time. That integral is then modified by at least one parameter generated by fuzzy logic from control conditions of the voltage. In this way the fuzzy logic may find the optimum control strategy which keeps the actual voltage closest to the reference voltage without an excessive number of tap position changes. The reference voltage may vary with time, and therefore the control of the voltage with time may be evaluated, and the control conditions varied accordingly, e.g. by fuzzy logic, so that the control arrangement can exhibit learning. Normally, the integral is modified such that

Voltage or reactive power control method and control device therefor

A gas blast circuit breaker comprises an insulation nozzle for blowing extinguishing gas to an arc generated between a stationary contact and a movable contact. The nozzle has a throat section into and out of which one of the two contacts is movable and a divergent section provided downstream of the throat section. A slanting surface for increasing a reflectivity of energy intensity of the arc is formed on the divergent section of the nozzle. The nozzle is formed of a fluoroplastic material and boron nitride powder of not more than 15 vol. % is added as a filler.

Gas blast, puffer type circuit breaker with improved nozzle

The invention relates to a synthetic equivalent test circuit which can generate a 4-parameter transient recovery voltage TRV, for verifying a large current breaking performance of a power circuit breaker. A current source current is supplied to only a testing circuit breaker which is to be tested and an auxiliary circuit breaker. A small current with respect to the current source current is transmitted to the first and second auxiliary switches from a power source. When the small current form the current source or the resonance circuit flows, the first auxiliary switch is opened almost simultaneously with the auxiliary circuit breaker, the testing circuit breaker and operates so as to break the current at the time point of the final zero point of the current source current. Therefore, the connection of the voltage source circuit just before the final zero point of the current source current, that is, the current supply of the voltage source current and the breaking of a capacitor circuit current by the first auxiliary switch generates a 4-parameter TRV that can be accomplished easily.

Synthetic equivalent test circuit of circuit breaker

An ion source device comprises a plasma generating vessel for generating plasma therein, a plurality of magnets arranged on an outer periphery of the plasma generating vessel to establish a cusp field in the plasma generating vessel, means for supplying a power to generate the plasma in the plasma generating vessel, and an anode electrode arranged on an inner wall of the plasma generating vessel and adapted to be heated by electrons emitted from the plasma and maintain the heat.

Ion source device

An ion beam for use in fabrication and processing of semiconductors, thin films or the like. For making uniform the radial distribution of an ion beam extracted from the ion source, a plasma chamber is formed by extending a plasma producing chamber in the direction in which microwave energy is introduced. The plasma chamber thus formed is provided with second magnetic means for generating a magnetic field of multicusp geometry.

Ion source

There is disclosed a high-voltage DC circuit breaker apparatus with reverse current insertion system by line voltage charge, which comprises a commutation switch, a series circuit of a capacitor, a reactor and a switch connected in parallel with the commutation switch, a resistor connected so as to charge the capacitor by a line voltage. The charging time constant of the capacitor determined by the capacity of the capacitor and the resistor is used as a reference in a manner so that the rise time constant of the line voltage is smaller than the charging time constant of the capacitor, and the rise time constant of the line current is larger than the charging time constant of the capacitor, thereby interrupting the fault current without fail.

High-voltage DC circuit breaker apparatus

A SF.sub.6 gas insulating electric apparatus usable as a circuit breaker, etc., containing a SF.sub.6 gas insulator and a resin insulator, both of which insulators are present in an atmosphere to be exposed to arcs, characterized by making at least the surface portion to be exposed to arcs of the resin insulator from a polymer containing nitrogen atoms or a polyolefin resin, and if necessary together with an inorganic filler powder, is excellent in both surface and inner arc resistance and can maintain breaking performance for a long period of time.

SF.sub.6 Gas arc extinguishing electric apparatus and process for

A puffer type current interrupter employing a pair of symmetric electrodes with contact bosses provided on their confronting surfaces. An insulator nozzle is arranged such that the throat section for providing a jet of arc blasting gas is located in the periphery of the bosses. The electrode structure provides a uniform electric field between the electrodes, thereby gaining the breakdown voltage.

Puffer type current interrupter

Disclosed is a gas circuit breaker of resistance breaking type, which comprises a main breaking unit and a resistance contact mechanism electrically connected in parallel with the main breaking unit for resistively cutting off current. With the opening action of the main breaking unit, a spring used for opening the resistance contact mechanism is energized and the energized force of the spring is released by a releasing mechanism after the current in the main breaking unit is cut off, thereby to act as a drive force to open the resistance contact means.

Gas circuit breaker of resistance breaking type

A grounded support tank type gas circuit breaker comprising a cylindrical tank maintained at ground potential and filled with an arc-extinguishing gas, and a breaking unit disposed within the tank with its central axis extending along the axis of the tank. In the circuit breaker, a capacitor unit is disposed within the tank in axially aligned relation with the breaking unit with its axis extending along an extension of the central axis of the breaking unit, so that the capacitor unit can be easily incorporated in the circuit breaker by merely increasing the axial length of the tank.

Grounded support tank type gas circuit breaker

An electromagnetic puffer type gas circuit breaker comprises two opposing puffer type gas circuit breaking units mounted on midway support means, actuating means for driving the circuit breaking units, an electromagnetic actuating unit drivingly coupled to the actuating means, and current transfer mechanism for transferring and applying the interrupting current to the electromagnetic actuating unit during a circuit breaking operation. The current transfer mechanism is located, in operative connection to the actuating means, at a point above the midway support means and in a spaced relation to the electromagnetic actuating unit. The contact surface area of the current-conducting path portion leading to the transfer mechanism is a fraction of that of another current-conducting path portion for the passage of most of the rated current. These features provide ease of inspection and replacement of the current transfer mechanism and reduces the operating force requirement of the breaker.

Electromagnetic puffer type gas circuit breaker

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Hitachi, Japan

Kunio Hirasawa