A Fault Line Selection Method for Single pole-to-ground fault in Flexible DC Distribution Networks

When the high resistance ground fault occurs in the flexible DC distribution network, the fault characteristics are weak and easy to be affected by noise, which leads to the difficulty of grounding line selection. To address this problem, a grounding fault line selection method based on the Hamming distance correlation coefficient of two-terminal zero-mode current is proposed. Firstly, the zero-mode currents at both ends of the line are selected as fault data, then, the Hamming distance between the zero-mode currents at both ends of the line is used to judge the difference between the lines, finally, the Hamming distance correlation coefficient is constructed to judge the fault line. The method proposed in this paper was verified through MATLAB/Simulink simulations, demonstrating its robustness against factors such as transition resistance, noise interference, fault location, and communication delay. Compared to Pearson and Spearman correlation coefficients, using the Hamming distance correlation coefficient for fault line detection offers higher reliability.