Hitachi, Ltd.

Chubu Electric Power Company, Inc.

Tokio Yamagiwa

Fumihiro Endo

Toshio Ishikawa

Jun Ozawa

Yukio Kurosawa

Koji Sasaki

Toshiaki Rokunohe

Hiroshi Arita

Youichi Ohshita

Tomoaki Utsumi

Yuzuru Kamata

Hiroki Honma

Yoshinori Tagawa

Shuzo Iwaasa

Hiroshi Yamada

Isao Takahashi

Akira Hashimoto

Kiyoshi Okumura

Izumi Yamada

Hashime Nagai

Ryouichi Shinohara

Mitsuo Sawairi

Toshiaki Ueda

Hideo Kawamoto

Masanori Tsukushi

Yasuro Hori

Shingo Shirakawa

Kunio Hirasawa

Junzo Kida

Shinichi Kondo

Toshio Akatsu

Sadao Mori

Manabu Takamoto

Katsuji Shindo

Satoshi Watahiki

Yoshihito Asai

Takahide Matsuo

Isao Nishida

Masaki Murashita

Hirohiko Yatsuzuka

Naoki Amano

Toru Tsubaki

Koji Kurokawa

Masayoshi Hashiura

Osamu Isshiki

Masaru Watanabe

Naoyuki Yamamoto

Yoshiaki Matsui

Shinji Fukuda

Masao Hosokawa

Shigetaka Takeuchi

Masahiro Shimokawa

Minori Satoh

Naoki Kasahara

Kenji Annou

Youichi Oshita

Yoshiaki Inui

Rikizo Ishikawa

Kaoru Endo

Takaaki Kawada

Masaru Fukuoka

Yoshikatsu Enokida

Masao Morita

Genzi Takahashi

Yosinori Tagawa

Akihiko Horide

Shigeyuki Sugimoto

Sadanori Neo

Kenji Anno

Kazutoshi Asano

To provide a gas insulation switch reducing the SF gas use amount without damaging the insulation performance and arc extinguishing performance, the present invention uses SF gas as insulating gas to be charged in the grounding tank of a unit having a switching unit of the breaker the disconnecting switches and and the grounding switches and for example, the line unit and uses gas having a smaller warming coefficient than that of SF gas, for example, nitrogen gas or air as insulating gas to be charged in the grounding tank of a unit having no switching unit, for example, the main bus units and and the connection bus unit

Gas insulation switch

This invention is to provide a transforming system capable of satisfactorily protecting the equipment of a substation even if a aerial electric power lines is struck directly by an intense electric shock of a large energy, such as an electric shock of a waveform similar to that of a thunderbolt stroke having a long duration of wave tail. So, this invention, a transforming system comprises, a lightning arrester, a ground fault device installed near a service entrance through which the power lines are led in, a voltammeter placed on the gas-insulated switchgear, and a control device receiving a signal from the voltammeter and providing a signal for controlling the grounding device. And when detecting of said thunderbolt arising in said aerial electric power line, a control device which order said ground fault device to make the ground fault condition.

Power transforming system and method

An insulated device diagnosing system is capable of judging the deterioration, lifetime, and defects of a device. The intensity at each voltage phase angle is measured at a plurality of specific frequencies, taking high voltage phase angles as the abscissas. The deterioration, lifetime, and the kind and extent of abnormality of the device are judged from the pattern and intensity of the spectral distribution, which is obtained by peak-holding the measured intensity for a defined time period. According to the present invention, partial discharge can be measured highly sensitively and precisely to diagnose the deterioration, lifetime and the extent of defect of the device. As a result, the insulation reliability of the device can be improved, and the part of the device that should be repaired/replaced can be grasped before disassembly of the device, thereby cutting the maintenance cost.

Insulated device diagnosing system that prepares detection data from partial discharge signal such that periodic elements are given to different specific frequencies of the partial discharge signal

A gas insulation switch has a container charged with insulating gas which contains an electric conductor and at least a pair of contactors. The container is divided into a plurality of sections. For the sections which have no switching devices or separable contactors, a different insulating gas is used as compared with that for the sections having breakers or separable contactors. In particular, in the section of the container, such as a grounding tank, that contains only electric conductors without separable contactors, an insulating gas having a smaller earth warming coefficient or global warming coefficient than that of SF,gases is used. On the other hand, for the section of the grounding tank which contains a breaker or switch having separable contactors, an SF,insulating gas is used. Since SF,gas is known to have a high earth or global warming coefficient, as compared with air or nitrogen gas, the SF,gas is only used as the insulating gas in the grounding tank for the sections in which superior arc extinguishing performance is required. Accordingly, the gas insulation switch has a reduced requirement for SF,gas.

A gas-insulated electrical apparatus includes tanks into each of which insulation gas is sealed, including bus-bars, bus-bar disconnectors connected to the bus-bars, circuit breakers connected to the bus-bar disconnectors, and line disconnectors connected to the circuit breakers, each line disconnector being further connected to a transmission or a transformer; wherein each bus-bar disconnector and each line disconnector include a respective pair of a fixed-contact and a moving-contact, the fixed-contact and the moving-contact being concave and convex, respectively, and each of the moving-contacts in the bus-bar disconnector and the line disconnector is located at the side of a corresponding circuit breaker between the bus-bar disconnector and the line disconnector, a contact-parting speed in the line connector being lower than that in the bus-bar disconnector.

Gas-insulated electrical apparatus

A bushing has a central conductor, and a plurality of internal shield rings. Gaps are formed between the shield rings such that equipotential lines extend through gaps. Electric field concentration in a tangential distribution on a part of the surface of the bushing corresponding to an upper part of an internal shield ring is relieved to prevent corona discharge under wet conditions, and antipollution performance and withstand voltage characteristics can be improved.

Bushing

In a gas insulated electric apparatus having gas sections filled with insulating gas, a locating device determines a position of a gas section in which an insulation abnormality is detected, on the basis of a detection signal from sensors disposed in each of predetermined gas sections. At the same time a hindering degree diagnosing device diagnoses the degree and the kind of the insulation abnormality, by comparing a detection signal from the sensors with data stored in a data base. A valve control generates a valve control signal, responding to the locating device and the hindering degree diagnosing device, and in response to the valve control signal, a trip circuit generates a valve opening signal to open an electromagnetic valve disposed in a gas section in which an insulation abnormality is detected. An insulating gas injecting and evacuating device injects an insulating gas, different from the initial insulating gas with which the gas sections are filled beforehand, into the gas section for which the electromagnetic valve has been opened by the valve opening signal, or evacuates a predetermined amount of the insulating gas with which the gas sections are filled beforehand, so as to increase insulation strength.

Gas insulated electric apparatus

A gas insulated switchgear has a container which is filled with an insulating gas, a conductor disposed with the container, an insulator for supporting the conductor. An outer periphery of the insulator is made smooth so as to improve a dielectric strength of the device. The insulator is made of an organic substance base and an inorganic material filler added to the base. In order to improve the dielectric strength, the filler is atomised or the insulator is coated.

Gas insulated switchgear

Insulated device diagnosing system for diagnosing device based upon

Light from a light source is fed to a sensing probe through a polarization plane-reserving fiber, and is split into two light beams, that is, a reference beam and a measurement beam. The reference beam is passed through a reference medium, and the measurement beam is passed through a pressure-sensitive medium, which may be in the form of gas. Then, the reference beam and the measurement beam are fed to a light-receiving portion via the polarization plane-reserving fiber, and are converted into electrical signals. The electrical signals are inputted into a signal processing portion, and the optical path length difference between the reference and measurement beams, passed through their respective mediums, is determined, and the pressure of the pressure-sensitive medium is detected from this optical path length difference.

Optical pressure detection method and apparatus

A gas filled electric conductor arrangement has an inclined surface (3A) at the bottom side of an electric conductor (3) that is formed by gradually reducing the cross section (D1, D2) of the electric conductor from one insulator spacer (2A) at one side toward another insulator spacer (2B) at the other side. Because of an angle (.theta.) of the inclined surface (3A), the spacing distance between the electric conductor (3) and the bottom surface (1A) of a grounded tank (1) increases depending upon the distance away from one insulator spacer (2A). Thereby, conductive foreign particles (50) are designed to be moved away from the surface of the insulator spacer (2A) and become trapped by a conductive foreign particle (1) disposed at the center bottom surface (1A) of the grounded tank.

Enclosed electric conductor arrangement

A ground fault current limiter, in which reactors are connected in series to a neutral point for compensating for capacitances to ground of a power switches capable of turning ON/OFF at a high speed are connected in parallel with respective reactors, occurrence of a ground fault is detected from a phase difference between a zero-phase sequence current and a zero-phase sequence voltage at time of sampling, an optimal compensation quantity of capacitances to ground is computed based on the zero-phase sequence current and the zero-phase sequence voltage at time of occurrence of a ground fault, and ON/OFF of the switches are controlled thereby to alter the reactor quantity so as to correspond to the compensation quantity.

Ground fault current limiter and method of limiting ground fault current

A gas insulated device includes a grounded tank filled with an insulating gas and having a conical insulator spacer securely mounted therein to define an interior space. A through-type electric connector extends through and is supported by the insulated spacer and an electric conductor is electrically connected to the through-type electric conductor by a conductor connector. The conductor connector closest to the insulator spacer is positioned such that electric flux lines exiting from the conductor connector intersect with the surface of the insulator spacer in a region in which an electric field has a strength equal to or less than 70% of the strength of the strongest electric field on the surface of the insulator spacer generated by a lightning impulse applied to the gas insulated device.

Gas insulated device, gas insulated switchgear, gas insulated bus line,

The number of hidden layers is no larger than 2 and a sum is determined for each case. A relationship between the sum of the inputs and teaching data for each case is expressed in a table in a descending order of the sum of inputs for each output of an output layer, and the teacher data for the maximum sum and the number of times of change in the teacher data are considered. A configuration (the number of hidden layers and the number of neurons thereof) is determined based on those data, and the coupling weights can be analytically calculated by using the table. Where the number of times of change of the teacher data is odd, some inputs do not route a second hidden layer.

Method of configuring a neural network and a diagnosis/control system

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Hitachi, Japan

Tokio Yamagiwa