Electric field computation on an insulating surface with discrete water droplets

Knowledge of the electric field along the external surface is a fundamental requirement for reliable assessment of electric discharge produced surface changes, degradation and flashover of outdoor insulation. Presented in this paper is a method of electric field computation on an insulating surface in the presence of discrete water droplets. The computational method is based on the charge simulation technique. The electric field intensification produced by water droplets is calculated and correlated with electric discharge activity that occurs on outdoor insulators under contaminated conditions. The results are useful for analyzing the performance of outdoor insulating devices, especially non-ceramic insulators, under contaminated conditions.