Numerical calculation of electric fields, losses and interfacial charge densities in water-treed dielectric composite structure

Results of the computer modeling and an analysis of electrical processes in a water-treed polyethylene (XLPE) are presented. The water-treed region is considered as a binary composite structure in frequency domain. Electric fields, energy losses and interfacial charge densities are calculated and are examined using a simplified layered model and 3D model of a real water-treed XLPE insulation. It is shown that the interfacial charges in the bulk of the composite structure build up mostly due to differences in conductive properties of the constituent phases, and the distributions of the electric fields and losses are determined also by the morphology of the water-treed region.