Impact of Inner Electrode Diameter on Surface Flashover under Nanosecond Pulsed Coaxial Electric Field

Either surface flashover voltage over interfaces between Nylon 1010 or polymethyl methacrylate(PMMA) and transformer oil nonlinearly increased and was immediately saturated with diameter of coaxial inner electrode under nanosecond pulsed coaxial electric field, and more larger inner electrode diameter more closer flashover voltage for both. Surface flashover properties are closely related to the electric field at the triple junction of solid-liquid-electrode and the field gradient along the interfaces between solid and liquid, so that the greater inner electrode diameter the higher flashover voltage was owed to resultant depressed field strength at triple junction and averaged potential distribution along interfaces.