Simulation of Surface Charge Accumulation on Polymeric Insulators at Low Pressure Conditions

Surface charging of polymeric materials has been a field of study for many years. The accumulated charge due to corona discharges disturbs the local electric field distribution, which further may lead to flashover. The influence of different factors such as surface roughness, humidity, electron irradiation, etc. on surface charge accumulation has been studied in order to predict the performance of polymeric insulators for various applications. At higher altitude, the insulators are subjected to low pressure conditions (where discharges will aggravate), so it is equally important to analyze their performance at low pressures. In this work we report the Multiphysics simulation carried out on surface charge accumulation on polymeric insulators at low pressure conditions. The surface charge density and the surface potential distribution are computed taking into account the plasma chemistry at different pressure values. It is evident from the results that the surface charge accumulation follows an increasing trend with the decreasing pressure owing to more discharge activities. For the selected geometry and the transient simulation parameters it is observed that the surface charge density attains the saturation roughly around 2000 ns.