The influence of thermal aging on absorption phenomena in cross-linked polyethylene cable insulation

Absorption-controlled charge and discharge currents in cross-linked polyethylene (XPE) cable insulation before and after thermal aging have been measured. The experimental dependences were analyzed in terms of the equivalent Voigt scheme. Known parameters of the Voigt scheme were used to calculate the frequency dependences of relative dielectric permittivity, loss factor, and loss tangent of XPE films in the region of low frequencies ($\omega$ = 10$^{-3}$–1 s$^{-1}$) at high temperatures. Results of analysis of the absorption characteristics of XPE were applied to modeling of the process of thermal aging of cable insulation.