Dielectric response of unaged and service aged MV XLPE cables

In this paper, dielectric measurements performed on unaged and service-aged 28 kV MV XLPE cables manufactured with strippable insulation screens are reported. Time domain dielectric spectroscopy was used covering the frequency range of 10/sup -4/ to 10/sup -1/ Hz at various voltage levels up to U/sub 0/. The aim of this paper is to characterize the dielectric response of various types of MV XLPE cables in order to identify features that could indicate the degree of aging. Dielectric measurement results were compared with water tree examinations that were performed on the same cables.