Application of UHF and HFCT partial discharge detection in GIS cable terminal defect

Power cable is widely used in urban power grid, whose safe and stable operation is of great significance to reliable power supply. By means of UHF (Ultra High Frequency) and other live detection methods, the cable faults can be detected in time, avoiding equipment damage and power failure. In this paper, a partial discharge defect of GIS cable terminal is found by UHF and HFCT (High-frequency CT) methods. The location of discharge power is determined by amplitude location and time difference location. The defect type is diagnosed by long time accumulative PRPD. The disassembly result shows that there is discharge trace on the surface of epoxy resin, there are yellow liquid drop and impurities on the terminal, and there are white mark and powder after drying of silicone oil. The disassembly result verifies the validity of online detection method and provides reference for preventing similar defects.