基于虚拟电容动态极性判据与FIR滤波器的谐振接地系统高阻故障定位方法OA

To address the challenge of locating high-impedance fault in resonant grounding systems,which are susceptible to unbalanced components and measurement noise interference,a fault location method based on virtual capacitance dynamic polarity criteria and Finite Impulse Response(FIR)filters is proposed.Through a theoretical analysis of high-impedance fault transient mechanisms,the method reveals a transient process dominated by zero-sequence network parallel resonance.It establishes dual polarity-amplitude criteria for virtual capacitance at upstream/downstream fault points,utilizing their sign differences for preliminary fault section screening.By combining differential filters with sliding accumulation filters,the method extracts fault components of zero-sequence voltage and current,respectively,suppressing power-frequency imbalance and high-frequency noise.The dynamic polarity criterion enhances signal robustness through feature fusion.A recursive location algorithm with an adaptive threshold elimination mechanism is further designed to achieve precise positioning under complex operating conditions.Simulation results demonstrate that the proposed method achieves accurate location across various transition resistances,fault inception angles,and strong noise environments,while maintaining complete robustness against unbalanced components.