Flashover inception voltage characteristic on polyimid surface under surge voltage application

To understand the flashover characteristics on polyimide (PI) surface, the flashover inception voltage under the surge application (Surge-FOIV) on the PI surface was measured in this paper. The FOIV under the DC voltage application (DC-FOIV) was also measured. The Surge-FOIV was higher than DC-FOIV. This is attributed to lower occurrence probability of an initial electron and/or lower growth probability of an electron avalanche under the surge application. In addition, the Sure-FOIV increased as both of half value width and repetitive frequency of the surge voltage waveform became bigger. It was considered that the surface charge injected from the electrode acted as home charge to the injection electrode, and the local electric field in the vicinity of the injection electrode relaxed. Furthermore, The Surge-FOIV also changed with the surge rate (surge/(dc+surge)) in dc voltage superimposed surge voltage. It was considered that the surface charge on the PI affect to the Surge-FOIV.