Rao Zhangquan

Air-gap discharge energy change characteristics in oil-paper insulation and the research on the correlation with the variation of gas

A test platform was built for the research on airgap discharge and its development characteristics which based on the air-gap discharge model in oil-paper insulation, and repeated carried out 36 hours partial discharge experiments using constant voltage method under the same conditions. Calculated the maximum discharge energy Wmax and the average discharge energy Wavg of the different discharge time. At the same time, average discharge energy per second Wasec was proposed as a new feature in which the discharge repetition was considered, the analysis showed that Wasec can characterize the the development characteristics of partial discharge very well. One the other hand, the dissolved gases in the oil were analyzed, the correlation analysis between six kinds of characteristic gas and Wasec showed that the content of H2 has the highest correlation with Wasec during the development of air-gap discharge in oil-paper insulation, followed by CO and CH4. The changes in the contents of these three gases can roughly reflect the variation of the Wasec. It has great significance in engineering practice.