Hitachi, Ltd.

Japan Ae Power Systems Corporation

Mitsubishi Hitachi Power Systems, Ltd.

Tatsuro Kato

Fumihiro Endo

Kazuo Kobayashi

Takeshi Ito

Toshiaki Rokunohe

Tomoaki Utsumi

Kazuhiro Saito

Ayumu Morita

Norihito Yanagita

Hiroaki Hashimoto

Yasuaki Aoyama

Hajime Urai

Tomohiro Moriyama

Ryoichi Shinohara

Yoichi Oshita

Takeshi Iwata

Youichi Ohshita

Katsuhiko Shiraishi

Hisashi Urasaki

Kenji Aoyagi

The invention is intended to provide a circuit breaker or a circuit breaker operating method enabling a current interruption action to be performed efficiently. A circuit breaker is characterized in that includes a fixed contact and a movable contact that comes in and goes out of contact with the fixed contact; a main circuit conductor that is electrically connected to the fixed contact and the movable contact; an operating mechanism including a mover configured by concatenating permanent magnets or magnetic materials alternately having opposite N and S magnetic polarities along the direction of motion axis of the movable contact and magnetic poles disposed to face the N and S magnetic polarities of the mover and wound with windings; a current detector that detects a current flowing through the main circuit conductor; and a control device that varies the amount of a current to be supplied to the windings of the magnetic poles, depending on a current value detected by the current detector.

Circuit breaker and circuit breaker operating method

An object is to provide a switchgear having a simple structure. To solve the problem, a switchgear according to the invention is characterized by having a fixed side electrode, a movable side electrodeconfigured to come into contact with or separate from the fixed side electrode, and an operating mechanism configured to allow drive force for movement of the movable side electrodeto be generated, wherein the operating mechanism for operating the movable side electrodeincludes one operating mechanism, and the one operating mechanism allows the movable side electrodeto stop at three or more positions.

Switchgear

Disclosed are equipment and method for diagnosing the sliding condition of a rotating electrical machine that make it possible to achieve early detection of abnormal sliding with a simple configuration containing flexibly arranged elements and reduce the downtime and maintenance cost of the rotating electrical machine. The equipment for diagnosing the sliding condition of a rotating electrical machine includes a light source that emits light onto the sliding surface of a collecting brush relative to the surface of a rotating body of the rotating electrical machine, a light-receiving section that receives the light reflected from the sliding surface, and a determination section that processes a signal from the light-receiving section. The determination section detects an increase in a specific wavelength component of the reflected light to determine whether the sliding condition of the rotating body surface of the rotating electrical machine is abnormal.

Equipment and method for diagnosing sliding condition of rotating electrical machine

In a wind power generator, a nacelle is located on an upper portion of a support rod, a rotor head having wind turbine blades fitted thereto is rotatably supported to a front end side of the nacelle, and a main shaft rotating integrally with the rotor head, a gear box coupled with the main shaft which rotates while the wind turbine blades receive a wind power, a power generator having a rotor driven by a shaft output of the gear box, a brush, and a slip ring, and a humidity management device controlling humidity inside of the power generator having the brush and the slip ring, are installed in an interior of the nacelle.

Wind power generator

The present invention is provided to satisfy insulation and conductivity performance requirements, to reduce the size of a gas insulated bus, and also to make conditioning for a particle more reliable. In a gas insulated bus having a conductor supported in a cylindrical metal container via an insulator, insulating gas being contained in the metal container, the metal container has an expanded diameter part formed over a given range in an area of the metal container in which the insulator is positioned and a reduced diameter part formed over the entire area of the metal container except for the expanded diameter part. Thus, when the temperature of the insulator increases during conduction, heat from the insulator is transferred to the metal container via a large space in the expanded diameter part and released to the air through a large outer surface of the expanded diameter part of the metal container.

Gas insulated bus and particle removal method for gas insulated bus

A gas-insulated apparatus is equipped with multiple sensors for sensing a partial discharge signal caused by a foreign substance, and a frequency analyzing section for analyzing the frequency of the sensed partial discharge signal. A defect type judging section estimates the defect type of the foreign substance from the signal obtained through the frequency analysis or from the voltage phase distribution of partial discharge synchronized with the frequency of the voltage applied to the gas-insulated apparatus, and a location determining section estimates the defect location and signal intensity from the multiple partial discharge signals. A defect size calculating section estimates the defect size for each defect type from the signal intensity and field distribution at the defect location. Dielectric breakdown risk evaluation is performed based on the defect size and type, and the insulation failure risk is diagnosed from the partial discharge.

Method and system for monitoring partial discharge in gas-insulated apparatus

In the measurement of partial discharge, a voltage detected by an antenna is input to a spectrum analyzer and a phase difference between an operating voltage and a power supply of the spectrum analyzer is obtained by phase domain analysis using the spectrum analyzer. Based on the phase difference and the voltage phase shift associated with the input impedance of a signal converter circuit, the time axis displayed on the screen of the spectrum analyzer is compensated. After the compensation has been carried out, the voltage detected by the antenna is input into the spectrum analyzer and the partial discharge pattern which synchronizes with the operating voltage is measured by phase domain analysis using the spectrum analyzer.

Method and system for measuring partial discharge

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushingsAs this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube

Gas insulating apparatus and method for locating fault point thereof

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushingsAs this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube 15.

The present invention combines sensor portionsof the device for measuring either current flowing through the line from the power inlet to the power outlet or voltage, or both, and bushingsinstalled at either the power inlet or the power outlet, or both, so as to reduce the size of the gas insulating apparatus. Specifically, the above-mentioned sensor portionsare installed in the space inside the porcelain tubethat constitutes the bushings. As this space, it is preferable to use the space on the outer-periphery side of the electric field relaxation memberprovided inside the porcelain tube

Gas insulated device and failure rating method

The present invention provides a method of diagnosing a partial discharge in a gas-insulated apparatus and a partial discharge diagnosing system for carrying out the same to achieve highly accurate diagnosis through the detection of a partial discharge signal and diagnosing the partial discharge signal through multiple conditional branching. The partial discharge diagnosing system of the present invention consists: a partial discharge signal detector for detecting a partial discharge signal representing a partial discharge produced in the gas-insulated apparatus, a signal analyzer for receiving the partial discharge signal detected by the partial discharge detector and analyzing the partial discharge signal, a diagnostic unit for determining a cause of the partial discharge on the basis of results of analysis made by the signal analyzer, and a display unit for displaying results of diagnosis. The diagnostic unit is provided with a diagnostic means to make multiple conditional branching to a plurality of second diagnostic apparatus according to result of diagnosis made by a first diagnostic apparatus, and obtains a result of diagnosis made by the second diagnostic apparatus, thereby achieving highly accurate diagnosis by detecting the partial discharge signal and subjecting the partial discharge signal to multiple conditional branching.

Method of diagnosing partial discharge in gas-insulated apparatus and partial discharge diagnosing system for carrying out the same

With a circular signal receiving antenna unit (,) constituted by combining two pieces of semicircular conductive plates on a plane in a metallic vessel (,) for the gas insulated apparatus, the electromagnetic waves due to the partial discharge can be detected with a high sensitivity for a broad frequency band. The detected signals are measured by a measuring unit (,) via a hermetical seal coaxial terminal (,) and a coaxial cable (,). The antenna portions of the semicircular plates are designed to extend over a large area. Thus, a capacitance with a potential measurement portion can be increased and a potential measurement with high sensitivity can be performed.

Partial discharge detector of gas-insulated apparatus

The present invention provides a method of diagnosing a partial discharge in a gas-insulated apparatus and a partial discharge diagnosing system for carrying out the same to achieve highly accurate diagnosis through the detection of a partial discharge signal and diagnosing the partial discharge signal through multiple conditional branching. The partial discharge diagnosing system of the present invention comprises: a partial discharge signal detector for detecting a partial discharge signal representing a partial discharge produced in the gas-insulated apparatus, a signal analyzer for receiving the partial discharge signal detected by the partial discharge detector and analyzing the partial discharge signal, a diagnostic unit for determining a cause of the partial discharge on the basis of results of analysis made by the signal analyzer, and a display unit for displaying results of diagnosis. The diagnostic unit is provided with a diagnostic means to make multiple conditional branching to a plurality of second diagnostic means according to result of diagnosis made by a first diagnostic means, and obtains a result of diagnosis made by the second diagnostic means, thereby achieving highly accurate diagnosis by detecting the partial discharge signal and subjecting the partial discharge signal to multiple conditional branching.

Growing community of inventors

Hitachi, Japan

Tatsuro Kato