Gas Heating in Positive- and Negative- Impulse Surface Discharges in Atmospheric Air

Flashover on the surface of dielectric materials gives extensive damage to the insulation system, resulting in reduced withstand voltage and system downtime as the damaged component is located and replaced. Therefore, the flashover on dielectrics has been studied for many years with the object of finding ways to reduce its incidence. Especially, a transition mechanism for streamer-to-leader is still the object of intensive experimental and theoretical studies. In the case of long-gap gaseous discharge, there is a proposed explanation that the transition-to-leader is occurred due to the joule heating of a streamer channel. While, there is no compelling explanation in the case of surface discharge. In this work, the change of gas temperature in positive- and negative- impulse surface…