If partial discharge measurement is added to the impulse voltage test

the type and severity of a insu lation fault of equipment can be detected more sensitively through analyzing the partial discharge quantity and characteristics.In this study

four kinds of typical defect models of oil-paper insulation were fabricated to simulate the electric field distributions under switching impulse voltage.The current sensor of self-integral Rogowski coil type was adopted to measure the high-frequency current of partial discharge.The four defect models of oil-paper insulation were tested under lightning and switching impulse voltage to reveal their partial discharge characteristics.Results showed that for same defect model

different switching impulse voltages resulted in significantly different waveform characteristics of partial discharge in time domain;while under the effect of same waveform of switching impulse voltage

the time-domain waveform characteristics of partial discharge showed clear difference for different insulation defect models.These results may be used to establish spectrum database of discharge characteristics corresponding to certain insulation defect model for identifying the partial discharge of different insulation fault types.