Evaluation of a polyolefin paper-oil composite as an EHV cable insulation

Since the early days of electricity supply (1890), impregnated paper based cables have been used for transmission and distribution purposes.¹ Besides a long record of cable reliability, paper insulation has unique characteristics such as a ruggedness which provides easy taping and subsequent bending of the finished cable and a porous matrix which allows easy flow of the imprégnant assuring a virtually void free composition with a high breakdown strength. However, the inherent electrical properties of the oil impregnated paper composition give rise to a limited power transmission capability for paper-oil insulated power cables at extra high voltage. This limitation has stimulated research on new transmission systems and new materials. This report is concerned with one of these efforts, namely, synthetic paper insulation.