Faulty Phase Detection Method Under Single-Line-to-Ground Fault Considering Distributed Parameters Asymmetry and Line Impedance in Distribution Networks

Accurate faulty phase detection under single-line-to-ground (SLG) fault is the basis of emerging voltage-based arc suppression technology. Most conventional recognition criteria assume distributed line-to-ground parameters are symmetrical, therefore suffering invalidity in actual distribution networks especially high-resistance ground-fault conditions. This paper firstly analyzes magnitude and angle variation models phase-to-ground voltages before after SLG fault. Considering asymmetrical line impedance, specific voltage rules corresponding to on each then discussed. Based rules, a robust practical method for identification proposed, which does not need parameters. Finally, correctness availability proposed verified by simulation. Comparative study shows has better accuracy applicability with methods when asymmetry resistance high.