Investigation on electrical treeing characteristics of thermally aged XLPE cable

Power cable insulation is subjected to thermal aging during its service life due to applied load or environmental conditions. Thermal aging may influence not only the electrical and physiochemical properties but also the initiation and propagation characteristics of electrical trees. In this paper we have investigated the electrical treeing behavior of XLPE cable insulation after accelerated thermal aging by using a physicochemical approach. Our results show that thermal aging have a strong influence on electrical tree growth. Thermo-oxidation-induced changes retard the electrical tree growth instead of promoting it. The probable factors which contribute towards this electrical tree retarding behavior are discussed in detail.