Analysis of Partial Discharge Behaviour under Staircase-based Sinusoidal Voltage Waveforms

This paper presents a comparison in Partial Discharge (PD) behaviour when an air corona setup is subjected to different waveforms, namely an idealized 50 Hz sinusoidal and staircase-based sinusoidal waveforms near inception voltage and at a higher voltage. In this study, it has been observed that the PD repetition rate and the Phase-Resolved PD (PRPD) pattern with the staircase waveform better resemble that of a pure sinusoidal waveform if the number of voltage levels of the staircase waveform is sufficiently increased. When observed more closely at the PRPD pattern near inception voltage, PDs tend to occur near the slope of the staircase waveform, even when the step voltage is small.