Electric Field Distribution and Leakage Currents in Glass Insulator Under Different Altitudes and Pollutions Conditions using FEM Simulations

The influence of pollution and atmospheric altitude on the dielectric performance of a glass insulator was studied by means of finite element analysis simulations. Contamination levels were represented by thin layers with different values of conductivities and thicknesses. Altitudes differences were simulated by equivalent voltages using correction factors. The results showed that by increasing the conductivity and altitude values, there was a considerable increase in the concentration of the electric field and leakage currents, changing from capacitive to resistive regime of electrical potential distribution along the insulator surface. The proposed levels of contamination and altitudes were analyzed by increasing the dimensions of the insulator according to IEC standards. In the case of the capacitive regime (conductivities lower than 10-4 S/m) there was a decrease in the electric field intensity up to 21% compared to an insulator at sea level. In resistive regime, a decrease up to 34.5% was obtained for leakage currents considering conductivities calculated according to the site pollution severity shown in the IEC standard. Despite the decrease of the leakage current after the increase of the insulator dimensions based on the standards, it did not mitigate all theoretical leakage current calculated along the insulator surface. Future work will focus on experimental research to validate this theoretical results.