Comparison of streamer propagation in mineral oils under lightning and step impulse voltages

Both step impulse and lightning impulse voltages were widely used to study streamer in liquid phenomena. This paper investigates the effects of voltage waveforms including step impulse (0.4/1400 μs) and lightning impulse (1.2/50 μs) on streamer propagation and breakdown under both positive and negative polarities. The results indicate that lightning impulse quenches the streamer propagation and leads to higher breakdown voltage compared to step impulse. However the acceleration voltages at 5 cm gap distance are the same between lightning impulse and step impulse. The observation is valid for both positive and negative polarities.