Development of high dielectric constant materials for cable accessories and design of XLPE MV cable terminations

A principle of “floating potential” for stress control on cable terminations has been designed, and compared to a typical resistive stress relieving of cable termination for crosslinked polyethylene (XLPE) cable power systems. For this case a computer program based on finite elements was developed for determining the electric field in configurations with both capacitive and resistive distribution of potentials. A tape having resistive stress characteristic has been used on the cable, and the coating materials comprised three types: SiC, ZnO and BaTiO₃. Finally, the samples of both terminations (classic one and with “floating potential”) made of these coating materials were tested in service conditions of load cycling. Good correlation has been proven between theoretical results and results obtained in experimental testing