Transient Energy Analysis based Single-Phase-to-Ground Fault Location in Distribution Networks

When single-phase-to-ground faults occur in neutral ineffectively distribution networks, the fault signals are weak, and it is difficult to locate the faulty line-section. In this paper, using the phasor measurement units (PMUs) in distribution networks, a fault location method is proposed based on the energy analysis of the transient zero-sequence current. The characteristics for transient zero-sequence current in faulty and healthy line-section are analyzed. The selected frequency band (SFB), where the transient zero-sequence currents lead or lag zero-sequence voltage at the same frequency 90 degrees, is determined and used to distinguish the faulty line-section. A new criterion on the basis of the relationship and the corresponding fault location technique is designed. Simulations and experiments verified the feasibility of the fault location method.