Electric field calculation in HV cable terminations employing heat-shrinkable composites with non linear characteristics

The use of the heat shrinkable tubes has been proposed as a possible solution to the problem of controlling the longitudinal component of the electrical field at the interface between the screen and the primary insulation in HV cables. However, typical materials adopted such as carbon black-loaded polyolefins show non linear characteristics, which have to be taken into account for a proper termination design. In this paper an analysis of the electric field in a cable termination using heat-shrinkable stress-relief tube is performed on the basis of a numerical procedure in which the material is simulated with a network of non linear resistors and linear capacitors