Influence of Capacitive Effects on the Characteristics of Creeping Discharges Propagating over Solid/Liquid Interfaces under Impulse Voltages

This paper is aimed at the study of the influence of the capacitive effects on the characteristics of creeping discharges propagating over solid/liquid interface namely the morphology, the density of branches, the final length and the electrical charge associated with this kind of discharges. The capacitive effects are investigated through the thickness and dielectric permittivity of solid insulator. Different solid insulating materials are investigated; the considered liquid is a mineral oil of naphtenic type. It´s shown that the surface density of branches and the final lengths of discharges as well as the electrical charge increase when the dielectric constant of insulator is increased and/or the thickness of insulator is reduced indicating thus the implication of the capacitive effects.