Dielectric response of laboratory aged PE cables

A time domain spectroscopy (TDS) measuring device has been developed at the Institut de recherche d'Hydro-Quebec (IREQ) to characterize the dielectric losses of HV polymeric insulation and a diagnostic is also proposed to assess the water-tree aging of polyethylene. The results obtained on new and aged miniature polyethylene (PE) cable samples show that: (i) the depolarization losses are strongly dependant on the polarization time and on temperature and (ii) the polarization and depolarization losses show a linear dependence with water-tree polyethylene degradation.