Abstract:The abnormal signals of partial discharge of 110 kV GIS basin-type insulator are detected and analyzed by UHF, ultrasonic, gas composition analysis and GIS intensive care system etc, and the discharge source is accurately locked in disconnector gas chamber through time difference positioning. Combining the characteristics of UHF spectrum and the location of discharge source, it is determined that there is an insulation discharge near the basin-type insulator in the gas chamber. After the gas chamber is opened, there are traces of ablation at the bonding between the basin-type insulator and the conductive rod of disconnector in the gas chamber. The poor assembly process of bonding causes burrs and air gaps in this part so as to form an uneven strong electric field and cause partial discharge. The discharge of basin-type insulator is a typical case of insulation discharge, which can provide a reference for the analysis and treatment of similar abnormal situations in the future.