Location Method of High-Impedance Fault Based on Transient Zero-Sequence Factor in Non-Effectively Grounded Distribution Network

High-impedance faults (HIF) occur frequently in non-effectively grounded distribution network. Because of small fault current, it is difficult to detect and locate HIF accurately by traditional methods. This paper proposes a location method based on transient zero-sequence characteristic factors. Firstly, the transient zero-sequence circuits of ungrounded and resonant grounded systems are simplified based on the analysis of transient frequency bands. Then, the transient factor and the ratio are defined and calculated according to the characteristics of transient zero-sequence quantities. Subsequently, the location criterion and scheme are proposed based on the difference in factor ratios, which are suitable for both ungrounded and resonant grounded systems. The defined factor and ratio are not affected by fault resistance, which makes the detection ability of HIFs strong. The reliability is improved using double-end information and multiple electrical quantities. The anti-noise ability is improved by selecting the transient frequency band. Compared with centralized methods, the data synchronization requirement and communication pressure are low, and the location speed is faster. Finally, simulations in PSCAD validate the transient zero-sequence characteristics and the feasibility and effectiveness of the proposed location method.