Simulation-Based Comparative Analysis of Electric Field Distribution and Flashover Risk in High-Voltage Glass Insulators under Pollution Levels

Abstract

High-voltage (HV) insulators are essential components in power transmission systems, ensuring electrical insulation and operational reliability. However, their performance is significantly affected by environmental pollution, which leads to surface contamination, non-uniform electric field distribution, and an increased risk of flashover. This study addresses the problem of insulation performance degradation under varying pollution conditions by investigating the relationship between pollution severity, electric field distribution, and flashover risk in a 132 kV transmission line insulator system represented by a single 11 kV glass disc model. The purpose of this research is to evaluate the effect of pollution severity on electric field behaviour and identify critical regions that are susceptible to electrical stress and flashover initiation. A finite element method (FEM)-based numerical simulation was conducted using COMSOL Multiphysics. A two-dimensional axisymmetric model was developed. Pollution conditions were modelled as a surface conductive layer with varying severity levels, representing clean, light, moderate, and heavy contamination.The principal results show that increasing pollution severity significantly distorts the electric field distribution along the creepage distance of the insulator. Electric field intensification is observed at critical regions such as the pin, sheds, and triple junction (air–glass–metal interface). Heavy pollution conditions result in severe field non-uniformity, which increases partial discharge activity and flashover susceptibility. The study concludes that pollution severity has a strong nonlinear influence on electric field distribution and insulation performance in high-voltage systems. The findings highlight the importance of considering environmental contamination in the design, operation, and maintenance of transmission line insulators.