The Effectiveness of Mitigation Schemes on Electric Field Intensity (Stress Control) for Overhead Line Glass Insulator

Abstract

This paper presents the simulation results of electric field distribution within suspension insulators ondifferent stress control techniques under dry-clean andpolluted conditions. Finite element method (FEM) isadopted to estimate the electric field behaviour along theinsulator profile. For this study, COMSOL Multiphysicsversion 5.3a is used to perform the modelling and executingthe field analysis. The effectiveness of zinc-oxide (ZnO)micro-varistor and grading ring as mitigation tools for theelectric field intensity enhancement was examined in thisstudy. The reference data from the dry-clean condition wasused as the benchmark to examine the effect of pollution onelectric field distribution on the insulator surface. It wasfound that the application of the combined techniques ofZnO micro-varistor and grading ring is the best scheme forstress control as it reduced the electric field intensity up toalmost 84% for both dry-clean and polluted conditions. Thisstudy also found that the positioning the grading and coronaring is crucial as it will affect the electric field intensitydistribution