Characterization Tests and analysis of cross-linked polyethylene (XLPE) used in high voltage cables insulation under thermal constraint

High voltage cables are permanently subjected to electrical and thermal operating constraints, leading to their progressive degradation and deterioration. The control and the identification of the thermal aging parameters of high voltage insulation require the use of several characterization techniques. In this work we have presented some results carried out from the use of different characterization techniques to study the mechanical and dielectric behaviors under thermal aging of cross-linked polyethylene (XLPE) used as insulation of high voltage cables. The evolution of XPE morphology under thermal aging was quantified with several physic-chemical characterization techniques such as FTIR, DSC and X-ray. The effect of thermal aging on the trapping and conduction mechanisms of XLPE under electron beam irradiation was also studied in the last part of this paper using SEM. The carried out thermal aging experiments consist to perform XLPE samples to elevate temperatures arranged from 80°C to 140°C until 5000h.