Electrical accelerated aging of EPR cable insulation energized by ac voltage and switching impulses

Ethylene Propylene Rubber (EPR) is one of the most common polymeric materials used in medium voltage power cable insulation. It is generally accepted that the cables will encounter electric stress, thermal stress and environmental stress during their service lives. All of the stresses will activate changes in the bulk properties of insulation materials, known as electrical aging, which will lead to the failure of cables. In the experiments for the study, the accelerated aging of EPR cable insulation is carried out by applying elevated ac voltage and switching impulses. The status of cable insulation is monitored through measurement of partial discharge parameters, dissipation factor, capacitance, and ac breakdown voltages. The study compares the accelerated aging of EPR cables by switching impulses and elevated ac voltage, which helps to understand the lifetime characteristics of EPR cables insulation.