Study on the Development of Discharge Pattern of Defect in Resin-Impregnated Paper Bushing Materials

Resin-impregnated paper(RIP) capacitive bushing is one of the important electrical equipment in the field of high-voltage power transmission. However, there is a lack of research on the change rule of insulation parameters under long-term operating conditions of the RIP bushing containing internal defect and the diagnosis of insulation defect of the RIP bushing. For the laboratory casting of RIP specimens containing metal foreign object defect, non-metal foreign object defect and bubble defect three types of specimens were studied in the partial discharge starting voltage and constant voltage long time defect in the process of the development of the characteristics of the discharge spectrum, comparing the discharge before and after the development of the tanδ-f curve of the law of change, in which the starting voltage of local discharge for metal foreign object defect is 10.2 kV, the starting voltage of local discharge for non-metal foreign object defect is 14.1 kV, and the starting voltage of local discharge for bubble defect is 13.7 kV. The discharge of metal foreign object defect undergoes two phases of increasing discharge frequency and increasing discharge amount, the discharge amount of non-metal foreign object defect is always maintained at 300–400 pC during the development of discharge, and the discharge phase gradually becomes wider with the increase of the withstand time, and finally becomes all-phase discharge, and the discharge amount of the bubble defect specimens increases gradually with the increase of the withstand time during the development of discharge, and the discharge peaks appear at 112.5°-157.5° and 292.5°-337.5° subsequently. °-157.5° and 292.5°-337.5° discharge peaks. According to the above specimen discharge development research results, for the RIP bushing long time defect discharge development research to provide the experimental basis.