Partial discharge current pulse characteristics of needle-plate electrode based on the high bandwidth measurement method

In order to obtain the nanosecond partial discharge pulse current signal of needle-plate electrode, a new measurement method of wideband PD pulse current has been proposed in this paper. By the numerical calculation of current parameters, the optimized needle-plate electrode structure and the accurate finite element simulation, the experimental platform of the fast PD pulse current detection was set up and its bandwidth was up to 1.81GHz. Then the PD characteristics of needle-plate electrode in pure N2 and different SF
₆
/N
₂
gas mixtures under power frequency voltage were investigated. The testing results indicate that, there are significant differences between PD current pulse when the gas atmosphere is changed and secondary electron emission process plays an important role for the PD current pulse waveform.