Partial discharge detection method and apparatus

摘要

To accurately determine the presence or absence of a partial discharge generated in gas-insulated equipment by eliminating influence of external noise. The method of determining partial discharge, wherein gas-insulated equipment, which is configured so that a cylindrical metal tank (1) sealed with insulating gas is partitioned by insulating spacers (2) and a center conductor (3) is supported by the insulating spacers (2), is observed for determining the presence or absence of a partial discharge generated in the metal tank (1), the method performs: extracting a signal of a frequency band in which only a TE11 mode propagates by a TE11 envelope detector (8) from electromagnetic wave signals detected with an electromagnetic wave detector (4) at a plurality of outer circumferential positions of the insulating spacer (2); obtaining an intensity distribution of outer circumferential electromagnetic waves in the metal tank (1) with an intensity detector (10) from the intensity of the extracted signal and the circumferential measurement position information; and determining the presence or absence of a partial discharge by comparing with a distribution peculiar to the TE11 mode by a determining device (11).