Simulation modeling of an insulation system with the development of a partial discharge in the volume of a solid dielectric

Partial discharges are electrical discharges in an insulation system confined to only a portion of the dielectric. They develop into gas bubbles formed in the volume of the solid dielectric. The Partial discharges are one of the main causes of insulation aging. Their single action has no practical effect on the insulation, but their prolonged action, accompanied by an increase in their intensity, leads to a slow destruction of the insulation and to its complete penetration. The article proposes a modeling of an insulation system with the development of a partial discharge in a solid dielectric.

I. Introduction

Partial discharges (PD) within an insulating material are usually initiated within gas filled bubbles within the dielectric. Because the dielectric constant of the void is considerably less than the surrounding dielectric, the electric field across the void is significantly higher than that across an equivalent distance of dielectric. If the voltage stress across the void is increased above the corona inception voltage for the gas within the void, PD activity will start within the void. The report proposes a modeling of an insulation system with the development of a partial discharge in a solid dielectric volume. The model is made according to a replacement circuit diagram. Process development in the insulation of a flat capacitor is reviewed.