Evolution of stress control systems in medium voltage cable accessories

Underground cable accessories used in medium voltage cable systems need a highly reliable stress control system in order to maintain and control the insulation level which is designed for estimated life times longer than 30 years of service. The term "electrical stress control" refers to the cable termination function of reducing the electrical stress in the area of insulation shield cutback to levels that preclude electrical breakdown in the cable insulation. This paper describes the evolution of stress control systems and their benefits, based on different materials and concepts. The main focus on this paper will be on the unique metal-oxide-matrix stress control system, which has never been attempted before.