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AssigneeHitachi, Ltd.
InventorsToshio Ishikawa, Shuzuo Iwaasa, Tomoaki Utsumi, Fumihiro Endo
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A method and apparatus for locating an abnormality in a gas-insulated electric device, operative to locate the spot of an insulation abnormality, which emerges inside a metallic container, from outside of said metallic container. A plurality of detectors (S.sub.0 -S.sub.n) disposed at certain positions in the metallic container produce detected signals, from which spectrum strengths (YH) in a high frequency band of 500 MHz or above are evaluated, and a position which renders a maximum spectrum strength is calculated from the relation between the spectrum strengths and the installation positions of the detectors and is determined to be the spot (x) of partial discharge.
A method of locating an abnormality in a gas-insulated electric device, in which a high-voltage conductor is supported by an insulation support member inside a metallic container filled with insulation gas, operative to locate the spot of a partial discharge emerging in said metallic container by means of a plurality of detectors (S.sub.0 -S.sub.n) installed at positions within said metallic container and which detect the partial discharge, wherein said detectors detect an electromagnetic wave caused by the partial discharge, the frequency spectrum of the electromagnetic wave is analyzed to evaluate the spectrum strength (YH), a position (x) which renders a maximum spectrum strength is determined from the relation between spectrum strengths of said detectors and installation positions of said detectors and an attenuation factor (.alpha.) of said electromagnetic wave generated and traveling within said metallic container, and said position (x) is determined in a longitudinal direction of said metallic container to be the spot of the partial discharge.
An apparatus of locating an abnormality in a gas-insulated electric device, in which a high-voltage conductor is supported by an insulation support member inside a metallic container filled with insulation gas, operative to locate the spot of a partial discharge emerging in said metallic container by means of a plurality of detectors (S.sub.0 -C.sub.n) installed at positions within said metallic container and which detect the partial discharge, wherein said apparatus comprises at least two detectors disposed with a certain distance therebetween for detecting an electromagnetic wave cause by the partial discharge;
Dependencies are inferred from the claim text.