Assessment of Leakage Current on Polymeric Insulator Using Finite Element Analysis

This paper develops a Finite Element Model (FEM) for a 138 kV High Temperature Vulcanized (HTV) Silicone Rubber (SiR) transmission insulator in which, in a first step, leakage current is calculated for different non-uniform continuous and discontinuous pollution deposits and then features based on the phase shift between the leakage current and the applied voltage are extracted for each kind of pollution layer to identify the existence of dry bands on the insulator surface. A phase shift of 84.75° lag between the leakage current and applied voltage was found for a pollution layer with dry bands inserted. This results evidence that the phase angle can be used to detect the dry band formation by measuring the leakage current and its phase angle.