Experimental Characterization and Mathematical Modelling of Surface Flashover of Solid Insulator in Air

This paper is aimed at the propagation of discharges over a surface of insulator and the development of an analytical flashover model in air at atmospheric pressure. The experimental results show that the critical conditions of flashover are over the half of creeping distance. Basing on electrical equivalent circuit and the impedance criterion, we developed a relationship giving the flashover voltage UFOV. This relationship suggests that flashover voltage is function of the discharge thermal parameters, the capacitance and the resistance of solid insulator and the propagation condition of the discharge. The UFOV computed using relationships we established elsewhere are found in a good accordance with the experimental ones.