Space Charge and DC Fields of Multilayer Dielectrics in Plane-Parallel Geometry

Space charge always assumes critical importance when it pertains electro-thermal problem of a dielectric subjected to dc stresses for dc cable insulation in particular. The significance of space charge only increases when multilayer dielectrics, cable joints in particular, are concerned. Interfacial polarization, complex electric field distribution and dynamic boundary temperatures greatly increase the probability of breakdown of a multilayer dielectric. Hence as an extension to the authors’ previous works this paper focuses on computation of space charge and its effects related to electric field and temperature profiles of a multilayer dielectric. Poisson’s equation along with Maxwell-Wagner interfacial polarization equation were used to obtain space charge distribution at different boundary temperatures and fields. Net charge accumulation in individual layers at different boundary temperatures and fields were determined.