Electrical Aging Phenomena of XLPE and EPR Cable Insulation Energized by Switching Impulses

During the operation of power system, the insulation of high voltage extruded cables will be placed under high electrical stress, including overvoltages caused by switching surges. In the study, 15 kV XLPE and EPR power cable samples are energized by switching impulses. The aging phenomena of cable insulation are observed by the measurement of partial discharge level and AC breakdown voltage during the aging process. The study helps to determine the reliability of power cables, as well as a better understanding of the aging mechanism. Many factors other than aging by switching surges have to be considered as an aging force for the insulation degradation.