Overhead line fault positioning method and system based on double-frequency signals

The invention relates to an overhead line fault positioning method and system based on a dual-frequency signal. The method comprises the following steps: S1, inputting a dual-frequency AC signal to an overhead line; s2, collecting a dual-frequency alternating current signal and a power frequency interference signal at the position of the current overhead line to obtain an initial collection signal; s3, sequentially performing signal windowing, signal zero padding, Fourier transform operation, amplitude correction recovery calculation and amplitude filtering calculation on the initial acquisition signal to obtain a processed signal; s4, resistive current and capacitive current at the current position of the overhead line are calculated based on the processed signals; s5, determining a total current value calculation formula based on the fault positioning mode, processing the post-signal based on the total current value calculation formula, the resistive current, the capacitive current or based on the total cur