Effect of Electrical Aging on the Trap Parameter of HVAC XLPE Cable Insulation

Abstract

The effect of electrical aging on the trap parameter of HVAC XLPE cable insulation was investigated in this work. Thermally Stimulated Current (TSC) was used to measure depolarization current. The variation of trap parameter was calculated by means of start-up method based on the Gaussian fitting curve of TSC data. It was found that, the activation energy and the amount of trap charge obtained from TSC peak at 243K and 348K were increased after electrical aging, which may be benefit to characterize the degree of aging. The amount of trap charge in the two peaks increases as the increase of oxide dipole after electrical aging. And charge trapped described by the TSC peak at melting temperature increased after aging. It is considered that the increase of charge in the TSC peak can be attributed to the release of trap charge in the melt crystallization process, which corresponds to the α relaxation process in XLPE insulation.