Study on fault phase selection based on FFT and phase-separation current phase difference of high-voltage transmission lines

The phase relationship of each phase on both sides of the short circuit point of the high-voltage transmission lines is analyzed in all kinds of fault conditions, and a reliable fault phase selection method based on phase-separation current phase is presented. In the fault phase selection process, the fault current component of each phase is computed first, and the phase difference is calculated by Fast Fourier Transform (abbreviation for FFT). Then the fault type is identified according to the fault current phase difference and the existence of the zero sequence current. Finally, the different fault conditions are verified by simulation, and the results indicate that the fault phase selection method presented in this paper is effective and feasible.