Shockwave phenomena in an inhibited gas‐to‐liquid hydrocarbon transformer oil under lightning impulse voltages

Abstract

Gas‐to‐liquid (GTL) transformer oil is increasingly considered as an alternative to conventional mineral oils, due to its consistent performance, high purity and essentially free of sulphur. This high interest has led to growing research attention on streamer and breakdown performance of GTL oil. A large effort has been made to characterise the streamer phenomena of GTL oil. However, the secondary effect of shockwaves, which are produced synchronously with the propagation of streamers, is not well studied. Shockwave phenomena in a GTL oil under standard lightning impulse voltages were studied using a 10 mm point‐plane gap and the Schlieren photograph technology. Shockwave propagation velocity and shape were measured in order to quantitatively describe the pressure profiles inside the streamer channels.