Development of a Series HVDC Cable Accessories Based on Silicone Rubber

The main insulation materials for cable accessories include silicone rubber (SR) and ethylene propylene diene monomer (EPDM) rubber. Compared with EPDM rubber, SR material has become the preferred material for AC cable accessories due to its good electrical, thermal and mechanical properties. Because the electric field distribution mechanisms of DC cables and AC cables are different, the electric field distribution depends on the insulation dielectric constant under AC voltage and the insulation resistivity under steady-state DC voltage. The application of SR materials in DC cable accessories has been affected to a certain extent by factors such as resistivity and space charge accumulation. The authors of this paper modified SR materials and developed medium-voltage, high-voltage, and ultra-high-voltage DC cable accessories, verifying that the electrical, thermal and mechanical properties of SR are also suitable for DC cable accessories.