High-impedance fault location method of three-phase distribution lines based on electromagnetic time reversal

Abstract

• Expanding the application scenario of the criterion of the minimum mirrored FCSE. • Accurately locating the single-phase HIF and identifying the fault phase. • Not affected by noise, GPS time synchronization, and the time delay of the device. • Location and diagnosis of single-phase HIF, phase to phase HIF, and three-phase HIF. Accurate location of high-resistance grounding faults in distribution lines is of great significance for improving the power supply reliability of power systems. In this study, a simulation model of a 10 kV three-phase distribution line is built using a numerical simulation platform. Further, a fault location method of three-phase distribution lines is proposed on the basis of the criterion of the minimum mirrored fault current signal energy (FCSE). The positioning accuracy of the high-impedance fault (HIF) is studied under different influencing factors. The results show that the proposed method can accurately locate the single-phase HIF of the three-phase distribution line, and the positioning error is within 50 m. However, it can only locate the fault when the fault resistance is 5 kΩ and below. In addition, the positioning accuracy of the proposed method for the HIF is not affected by noise and the sampling frequency, although the location accuracy under different fault inception angles is affected by fault resistance. Further, when the GPS time synchronization error is within 2 μs or the time delay of the transient signal device is within 2 ms, accurate positioning of the single-phase HIF can be realized. Moreover, by analyzing the three-phase FCSE distribution calculated in the reversed time, positioning and diagnosis of three HIF types, namely the single-phase grounding fault, phase-to-phase fault, and three-phase grounding fault, can be realized. Finally, fault phase identification of the single-phase HIF can also be achieved.