Insulation properties of cross-linked polyethylene cables cured in inert gas

Abstract

A new method of cross-linked polyethylene cables, vulcanization in inert gas, was researched and developed. In this paper, the principle of the new method of the gas curing process is explained. And then the electrical and physical properties of the cables cured in inert gas are outlined and are compared with those of the cables cured in steam. It is found that the curing method and condition have heavy influence on the micro-structure of the XLPE (cross-linked polyethylene) insulation and electrical strength. In conclusion, we can cure the polyethylene cables in the flow of the high temperature and high pressure inert gas. A.C and impulse breakdown voltage of the cables cured in inert gas (gas-cured cable) were respectively higher about 50∼70% and 20∼ 70% than those of the cables cured in steam (steam-cured cable). By our new method of the gas curing process perhaps insulation thickness will be reduced to 70∼60% of that of the present steam-cured cables. It will be of great advantage to use this method in manufacturing EHV XL-PE insulated power cables.