Abstract: Abstract: When a single-phase ground fault occurs in the distribution network, empirical mode decomposition (EMD) is applied to the transient zero sequence currents uploaded by FTU installed along feeder lines. Adaptively obtain a limited number of intrinsic mode function components (IMF) from high frequencies to low frequencies. Select the highest frequency IMF component for Hilbert transform to detect the instantaneous frequency mutation point and mark it as the fault moment. The first-order difference value of the highest frequency IMF component at the fault time is obtained, and the difference product is made between the adjacent detection points. The positive and negative values form a section location criterion.