The distribution network with small current grounding mode can ensure high power supply reliability, but it is difficult to locate single-phase grounding fault line. Most of the faults in distribution network are single-phase to ground fault. It is important to locate the fault line timely and accurately for the normal operation of the power grid. In this article, a fault line selection method based on signal injection is proposed. The dynamic selection of parameters and injection frequency in

more »

... eal-time monitoring distribution network by injection method is analyzed. The accuracy of signal frequency domain conversion is improved by using all phase Fourier transform. Taking the active power consumption of injected signal after fault as the criterion, the accuracy of line selection is improved. Through theoretical analysis and simulation, as well as experiments in a 600V distribution system, the fault line can be accurately selected. INDEX TERMS Fault line selection, signal injection method, non-effectively earthed neutral, single-phase to ground fault.