Dielectric strength of crosslinked polyethylene insulation part II effect of impregnation and in situ polymerization

10 November 2016

conference paper
Published by Institute of Electrical and Electronics Engineers (IEEE)

p. 195-205
https://doi.org/10.1109/ceidp.1978.7728214

Abstract

Crosslinked polyethylene, an ideal insulation for high voltage transmission and distribution cables, often contains a large number (≈10⁶ per cm²) of microvoids.¹ The electric stress intensification occurring at these voids can lead to electrical² and electrochemical treeing.³ We reported in an earlier communcaiton⁴ that impregnation of slabs cut from a 138 kV cable with mineral oil and polyethylene wax increases the dielectric strength. These imprégnants are liquid at the peak service temperature (90°C) and hence they may exude during the service life of the cable. We propose that impregnating the cable with a monomer-catalyst solution and polymerizing the monomer insitu may heal the voids permanently. In this paper we will present the results of impregnation of crosslinked polyethylene slabs with two monomers (lauryl methacrylate and vinyl toluene) and their subsequent insitu polymerization through free radical initiation. The effect of impregnation on void filling and breakdown strength will be discussed.

Keywords

This publication has 0 references indexed in Scilit: