Abstract Taking the actual permanent fault of DC line as an example, this paper analyzes in detail the treatment process of DC control and protection after the permanent grounding fault, the reason why the fault is not isolated in time and the circulation circuit of fault current. In order to isolate the fault more timely, considering the shunt capacity of the neutral bus switch, this paper proposes two strategies: phase-shifting restart and power drop back, analyzes and compares the advantages and disadvantages of the two strategies. Different strategies can be selected according to the configuration of the primary equipment on the project site. Finally, the feasibility and effectiveness of the proposed strategies are verified by real time digital simulation (RTDS) experiments.
2021, Vol. 22 
