Influence of voltage and load current on dc bipolar corona pulses

Digitizing oscilloscopes were used to observe anode and cathode corona pulses on a laboratory scale HVDC bipolar transmission line. Data was collected with the transmission line energized at a nominal voltage of ±60 kV with no load current. The effects of increased voltage and added load current were then separately investigated. Histograms show distributions of corona pulse amplitude and time between consecutive corona pulses (corona pulse time separation). Increasing the transmission line voltage had the effect of increasing corona pulse amplitude and decreasing corona pulse time separation for both anode and cathode. Addition of load current decreased the corona pulse amplitude and increased the corona pulse time separation for the anode. The cathode corona pulse amplitude and pulse time separation decreased with the addition of load current