Power distribution network single-phase earth fault section positioning method based on asynchronous signals

The invention relates to a power distribution network single-phase earth fault section positioning method based on asynchronous signals, and the method comprises the steps: determining a single-phase earth fault moment, and collecting the zero-sequence current of each section in two power frequency periods after the fault occurs; performing decomposition by using a pole symmetry mode decomposition method to obtain an intrinsic mode function and a margin function of which the frequencies are from high to low in each section; calculating a minimum DTW distance of a margin function between adjacent sections, and normalizing the minimum DTW distance as a data feature of single-phase earth fault section positioning; and calculating the LOF of the data features by using an LOF algorithm, and judging a fault section according to the size of the LOF. According to the method, only zero-sequence current of two power frequency periods after the fault is needed, data acquisition is simple, applicability is high, fault se