Gas Heating and Streamer-to-Leader Transition of Impulse Surface Discharge on Quartz Glass in Atmospheric Air

Flashover on the surface of dielectric materials often causes extensive damage to the insulation system, resulting in reduced withstand voltage and system downtime as the damaged component is located and replaced. Therefore, understanding the flashover mechanism on dielectrics is of great significance to reduce incidences. In this work, the change in gas temperature in an impulse surface discharge during streamer-to-leader transition was measured in atmospheric air by the spectroscopic method. In the experiment, a quartz glass having a conductive indium tin oxide-coated back-surface was used as an insulation material having a back electrode. As a result, the increase in gas temperature in a discharge channel was confirmed when the discharge phase transformed into a leader.