Direct-current line fault positioning method and related system and device

A DC line fault positioning method comprises the following steps: respectively collecting two end fault waveforms at two ends of a DC line; performing data preprocessing on the two-end fault waveforms to obtain two-end effective fault waveforms; inputting the effective fault waveforms at the two ends into a pre-established full-line transmission function and segmented line transmission functions at the two sides of the fault point to obtain an inverse transformation filter; performing waveform inversion on the two-end effective fault waveform according to the inverse transformation filter to obtain two-end fault correction waveform data; calculating a fault position value according to the time difference between the fault correction waveform data at the two ends; the full-line transmission function is calculated by utilizing a self-adaptive filtering algorithm based on artificial short-circuit data; the segmented line transmission function is obtained by comparing data at two ends and combining the whole line