Accelerated electrical degradation of 15 kV EPR cable under dry and wet condition energized by switching impulses

Medium voltage power cables are manufactured with various insulating materials. Ethylene Propylene Rubber (EPR) is one of the most common materials used in cable insulation among them. It is known that power cables in service are subjected to moisture due to wet environment which may reach the insulation and accelerate environmental aging of insulation. In the experiments set for this study, the accelerated electrical degradation of the cable is carried out by applying switching impulses; the cable was situated in dry and wet condition. Partial discharges parameters, capacitance, and dielectric loss factor were observed at regular interval during aging of the cable. AC breakdown voltage test was performed at the end of aging. This study compares the accelerated aging of EPR cable by switching impulses under dry and wet conditions, which helps to estimate the lifetime aging characteristics. However, many other conditions have to be taken care of besides wet condition for precise estimation.