The HEM research group has successfully developed the based on SiR inslulating ±500kV HVDC cable accessories. The rated transmission power of our design can reach 3GW in a ±500kV HVDC-VSC cable system. In Oct 2020, these cable accessories have successfully passed the type tests with ±500kV DC Submarine Extruded Cable at a qualified testing facility (ISTCW, Shanghai Intelligent Service and Technology Co. Ltd., CNRS certification see below). Previously, DC cable accessories of the same voltage level developed by other manufacturers were all based on EPDM rubber insulation.

CNRS certification