Measurement of partial discharge pattern on typical defects in GIS

Gas insulated switchgear (GIS) is the most important equipment in the power grid. Especially, for insulation failure, the monitoring, analysis and pattern recognition technology of partial discharge in GIS is the most important. Thus a 220 kV GIS bus bar cavity was taken as an object to design three PD physical models. The PD signals on different defects were detected with the IEC60270 method. The effects of the applied voltage on the center-phase distribution and average amplitude of the discharge pulses were investigated. The experimental results indicated that the phase-resolved PD (PRPD) patterns, average amplitude and central phase changing of PD signals had very similar distribution characteristics and those of different defect had different ones. The results provide a test basis for the recognition of PD types and a deeper study of the mechanism of PD.