Electromagnetic Time Reversal Fault Location Method Based on Characteristic Frequency of Traveling Waves

In its application to locate ground faults, the electromagnetic time reversal (EMTR) method uses voltage from only a single point. However, when a high-impedance fault (HIF) occurs, the reflected signal from the fault point is weak, leading to an error between the simulated and actual fault location results. This paper proposes a new EMTR method based on the characteristic frequency of the traveling wave reflecting from the fault point. First, the transient signal spectrum under different fault resistances was analyzed, and the reasons for the inapplicability of the existing EMTR method under HIF conditions were discussed. Subsequently, a single-end signal expression with fault resistance was deduced, and the applicability of the EMTR method, which involves calculating only the energy of the fault current at the characteristic frequency, was verified. A reduced-scale experiment and a simulation in PSCAD were performed, and the EMTR method and proposed method were compared. The results showed that the proposed method can be applied to different complex lines, and it outperforms the conventional EMTR method in the event of HIFs.