Hitachi, Ltd.

Japan Ae Power Systems Corporation

Tomohiro Moriyama

Jun Nukaga

Toshiaki Rokunohe

Akira Yamagishi

Li Lu

Yasutomo Saito

Satoshi Ichimura

Fumihiro Endo

Tatsuro Kato

Takayuki Nakakawaji

Makoto Hirose

Kazuhiro Satou

Hiroyuki Akata

Yoshio Hamadate

Ryoichi Shinohara

Yoshiaki Seya

An oil leakage detector of the present invention includes an image processing unit wherein the image processing unit calculates the values of saturation and intensity of each pixel in the color image of the object after an ultra-violet light is irradiated thereon, draws an intensity-saturation characteristic line of the saturation expressed in an X-axis and the intensity expressed in a Y-axis, sets an upper limit and a lower limit of intensity of each saturation as a threshold value based on an area without oil adhesion on the surface of the object, and determines, in the intensity-saturation characteristic line, an area corresponding to a pixel group where the intensity exceeds the threshold value of the upper limit and a pixel group where the intensity falls below the threshold value of the lower limit, to be an oil leakage adhered area.

Oil leakage detector and oil leakage detection method and image processing unit

A leakage oil detection system includes a measurement device including a light source that causes a measured object which includes a leakage oil attachment part to be irradiated with ultraviolet rays, and an imaging device that detects fluorescence emitted from the leakage oil attachment part which is irradiated with the ultraviolet rays, and performs imaging on the measured object; and an analysis device that includes a driving control unit that controls operations of the light source and the imaging device, a recording unit that records an imaged image of the measured object which is imaged by the imaging device, and an image processing unit that calls the imaged image which is recorded in the recording unit and performs an image process to detect leakage oil.

Leakage oil detection system

Provided is a lubricant for a gas insulated switchgear, with which properties of a base oil such as heat resistance, evaporation loss, fluidity under a low temperature, and chemical stability (oxidation resistance and HF resistance) are balanced at a level higher than the conventional level, and long service life and high reliability of the gas insulated switchgear are achieved. A lubricant for a gas insulated switchgear according to the present invention, contains: a base oil containing a polyalphaolefin having a kinematic viscosity at 40&#xb0; C. of 50 mm/s or more; and a thickener containing bisamides.

Lubricant for gas insulated switchgear, and gas insulated switchgear

A system and method for detecting leakage oil with a high degree of accuracy while avoiding the complexity of the system and the influence of noise light comprise: ultraviolet light sources arranged to irradiate an oil-filled device from a plurality of different incidence angles, and are switched on and off at the respective incidence angles in sequence, and include a wavelength exciting oil; an imaging device to photograph the oil-filled device irradiated with ultraviolet light emitted from the ultraviolet light sources when the ultraviolet light sources are switched on; a recorder to record respective images photographed by the imaging device; and a display to display the respective images. The respective images are compared, a site where a light emitting position does not change always is judged as a leakage oil site, and a site emitting light or not emitting light occasionally is judged as a noise light site.

Leakage oil detector system and method

Oil leakage detector and oil leakage detection method

Disclosed is a power switch gear that includes: a fixed electrode and a movable electrode disposed opposite to each other in a tank filled with insulting gas; and a movable conductor electrically connecting the fixed electrode and the movable electrode together. The fixed electrode and the movable electrode have a contactor through which current flows to the movable conductor. At least one of the fixed electrode and the movable electrode has ring-shaped sliding members, the ring-shaped sliding members being disposed, on both sides of the contactor. At least one grease pool is provided between the contactor and the sliding members.

Power switchgear

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.

Growing community of inventors

Tokyo, Japan

Tomohiro Moriyama