FEM analysis of electric field distribution for polymeric insulator under different configuration of non-uniform pollution

Considering the extensive use of high voltage insulators, the reliable performance of insulators is challenged by various weather conditions such as pollution. According to recent researches under unidirectional wind, polymeric insulators are mostly exposed to non-uniform fan-shaped pollution. In many contamination patterns, the internal surface is covered with higher contamination than the external surface, and the non-uniform contamination shape on the insulator is similar to a ring-shape. In this paper, two conventional types of non-uniform pollution known as fan-shaped and ring-shaped are modeled for a 20 kV polymeric insulator, and a comparison is made in terms of the electric field between the two configurations using different thicknesses and electrical conductivity of the pollution layer. The electric field, during the arc length of the insulator, is studied under clean conditions, uniform contamination, and two types of non-uniform contamination. In addition, the effect of various thicknesses and conductivity of the pollution layer on the electric field distribution of this polymeric insulator is analyzed. The results show that the electric field distribution in non-uniform ring-shaped pollution is much more effective than the fan-shaped type by changing the thickness of the contamination layer. Moreover, ring-shaped pollution has a more uniform field distribution with fewer thicknesses of contamination layer.