Creeping discharge and flashover of solid dielectric in air at atmospheric pressure: experiment and modelling

This paper is aimed at the study of the propagation of discharge at the surface of solid insulator and the development of an analytical model of flashover in air. The experimental results show that the critical conditions of flashover are met when the discharge reaches the half of creeping distance. Using electrical equivalent circuit and the impedance criterion, we developed a relationship giving the flashover voltage (FOV). This formula evidences the fact that flashover voltage depends on the discharge temperature, the capacitance and the resistance of solid insulator, and the propagation conditions of the discharge. We also show that the computed FOV are in a good accordance with the experimental data.