A review of the composite dielectric insulated underground transmission cable

The authors present a brief assessment of the experience gained with synthetic dielectrics as applied to solid extruded cables and review the up-to-date work carried out on the development of oil-filled commercial cables insulated with polypropylene laminated paper (PPLP). The primary emphasis is placed on the relative comparison of laminated-paper-insulated conductors for their electrical design and performance characteristics to that of conventional oil-impregnated paper cables. The excellent electrical characteristics of the PPLP material have been successfully demonstrated on full-size cables in different parts of the world, leading to the conclusion that PPLP is a superior high-voltage dielectric with a great potential of substitution for the conventional kraft paper insulation. The effective tolerance of this material for operation at substantially higher electrical stress levels has also been shown. The potential for savings with PPLP is shown to be great