Flexible Grounding Line Selection Based on Power Variation

Aiming at the difficulty of flexible grounding line selection, a fault line selection method based on the phase change characteristics of zero sequence power is proposed. Based on the equivalent circuit of single-phase grounding fault in flexible grounding system, the difference characteristics of zero-sequence active power between intact line and fault line before and after neutral point parallel connection with small resistance are analyzed. It is found that there are significant differences between the waveforms of low-frequency reactive components of intact lines and faulty lines. The difference of steady-state zero-sequence active power between lines is compared by Hausdorff distance algorithm, and the implementation scheme of fault line selection is designed through the fault line selection criterion of Hausdorff distance parameters. The correctness and effectiveness of the proposed line selection scheme are verified by the calculation and analysis of Matlab simulation and experimental waveform records.