Space Charge Formation in XLPE - the Influence of Electrodes and Pre-conditioning

The composition of the inner and outer “semicon” shields in modern ac cables, and the temperature/pressure conditions under which the various manufacturing procedures are carried out, would be expected to influence space charge accumulation under dc stress significantly. However, few systematic investigations of the influence of these factors, on space charge accumulation or other electrical properties of XLPE, have been reported.

In this paper we present space charge profiles for a range of XLPE planar samples under dc stress. Three different types of semicon electrodes were investigated, as well as vacuum-evaporated gold. The samples were also subjected to three different heating/pumping conditioning procedures.