A study on controlling electrical stress of underground cable by semi-conductive shielding

This paper presents a study on controlling electrical stress of high-voltage underground cables by semi-conductive shielding. Except impurities and cavities of the insulation material, most high-voltage underground cable insulation failures are caused by unusual energy dissipation conditions on the interface of insulation and semi-conductive layers. This paper investigates the principles of using semi-conductive shielding to control electric flux distribution and to constrict voltage between the shielding and the surface of insulation layer. In addition, termination fault analysis and study cases for using electrical stress control devices are also presented to show how the semiconductive shielding can be used to mitigate the nonuniformly distributed high electrical stress and to improve the voltage withstand level of the insulation layer.