Polyethylene as a high voltage cable insulation

In 1894 the first oil-impregnated paper-insulated lead-sheathed cable was used for high-voltage power transmission in the United States. For approximately fifty years no serious challenger appeared on the scene, and even at present, more than seventy years later, paper-insulated cable is still very much in use for all voltages from 15 kv up, and in one form or another is the only insulation used commercially in the 230–345 kv range. However, in the range from 5 kv (or lower) up to 138 kv, a 30-year old material, polyethylene, has seen increasing service. This paper will outline the requirements for a high-voltage cable insulation, and will investigate the extent to which polyethylene meets these requirements.