Influence of Surface Resistivity on Flashover Properties of Epoxy Insulator in Arc-decomposed SF6 Gas

This paper studies the relation between AC surface flashover voltages (FOVs) of an epoxy insulator and the surface resistivity in arc-decomposed SF
₆
gas. It was found that as lowering the surface resistivity the FOV decreased and approached a constant value below the surface resistivity 109 ohm/square. The FOV characteristics and the discharge traces suggest that the flashover phenomena are divided into three regions depending on the surface resistivity, which can be explained by a transition from a capacitive field to a resistive field of the insulator and also by the surface non-uniform deterioration due to the arc-decomposed gas