Comparison Of Partial Discharge Measurement Methods Under The Oscillating Lightning Impulse Voltage In Gis

Partial discharge measurement of a floating electrode defect in GIS under power frequency and the oscillating lightning impulse voltage are investigated in this paper. Partial discharge measurement under power frequency voltage is carried out based on IEC60270 standard by which a typical partial discharge characteristics of a floating electrode defect in GIS is demonstrated. The high frequency current transformer (HFCT), a UHF antenna and a coupling capacitor in series a coupling device are used to measure the partial discharge under the oscillating lightning impulse voltage whose waveform parameters are defined in IEC60060-3 standard. Partial discharge measurement of a floating electrode defect in GIS under the negative oscillating lightning impulse voltage is carried out in this paper. These results suggest that the sphere gap triggered interference and sphere gap reignited interference can not be detected by UHF method, but the HFCT PD sensor and the PD sensor with coupling capacitor in series a coupling device can detect them, moreover, UHF sensor has more dramatic signal-to-noise ratio than other PD sensors. Therefore, the UHF is a very promising PD measurement method under the oscillating lightning impulse voltage in GIS.