Investigation on Influence of Thermal Aging on Water Tree Inception in XLPE Cable Insulation

Thermal aging may influence not only the electrical,physicochemical and other properties of the XLPE cable insulation,but also the initiation and propagation of water tree inside it.This paper aims to investigate how the thermal aging influence the water tree behavior of XLPE cable insulation and which factor is the most influential to water treeing phenomena inside it.The experiment investigations on the influence of thermal degradation to the water treeing behavior of XLPE cable insulation show that thermal oxidation is the most influential to the initiation and growth of water treeing from the surface of XLPE cable insulation among all the probable factors caused during thermal aging and that thermal oxidation is observed to inhibit the growth of water tree inside XLPE insulation and to have so-called tree-retarding effect although it tends to provide the inception points for water treeing.