Computation of Electrical Potential Distribution along Insulator covered with Thin Conductive Pollution Layer

The electric field behavior, in particular the field intensification at the interfaces of dielectric materials of different thicknesses and properties, is very important in insulating systems. The main purpose of this work is to compute the electric potential distribution for insulator covered with a thin polluted layer. For more realistic and accurate field modeling, the pollution deposit is treated as a thin layer by introducing both conductivity and permittivity of this layer. FEM commercial software Comsol Multiphysics is first used to compute the potential distribution on a simple plate insulator model and then an analytic solution of the electric potential based on surface currents is proposed. Numerical and analytical results are compared for different ranges of conductivity and permittivity.