A new approach to the electric aging of dielectrics

Abstract

A simple model partially based on the rate theory is proposed to describe the electric aging of polyethylene (PE) and cross-linked PE (XLPE) cable insulation. It is assumed that the stress (electric or mechanical) reduces the height of the energy barrier controlling the process under study. The model describes very different effects of high electric fields on the properties of polymers. It relies on two parameters whose physical significance is discussed in the light of electric aging of PE and polarization reversal of PVDF. A preliminary study indicates that very long lifetimes of polymers can be achieved provided the applied field is lower than the critical field controlled by the chemical and morphological structure of the material.<>