What are the main functions of the inner and outer semi-conductive shields in power cables?
The inner semi-conductive shield eliminates the air gap between the conductor and the insulation, equalizing the electric field on the conductor's surface. The outer semi-conductive shield eliminates the circular, flat air gaps that form between the insulation and the metal shield when the cable is bent or subjected to cold or heat, equalizing the electric field on the insulation's surface. Both layers function primarily to equalize the electric field and prevent partial discharges on the inner and outer surfaces of the insulation.
