Research on common grounding electrode in HVDC

Compared to regular independent ground electrode, common grounding electrode has its own technical challenges and more complex aspects to be considered in the design. The characteristics between common grounding electrode and regular independent ground electrode are presented in this paper. The different forms that common grounding electrode can adopt and the applicability of each form are analyzed. The main operating mode, the selection of the system conditions, the designed life, the maximum allowable temperature rise and the maximum allowable step voltage of common grounding electrode are of particular analysis here. All that above can be used as references for future design of common grounding electrode. Finally, it is theoretically analyzed that establishing the disconnecting switch on the lead-in line of common grounding electrode can facilitate the maintenance of the grounding line and common grounding electrode, also it can reduce the impact between the DC systems associated by common grounding electrode.