Fault-location method for HVDC transmission lines based on phase frequency characteristics

A novel high-voltage direct-current (HVDC) line fault location method based on phase frequency change characteristics is proposed. The idea of the method is the travelling waves for the fault happened on different positions have different phase distortion characteristics, when they spread to the measuring terminal. By using the discrete Fourier analysis, the phase frequency characteristics were obtained. The frequency data of 40 to 60 Hz and the corresponding phase angle ratio data are selected, forming a N x 3 matrix, each row of data represents the relationship between the fault location and phase angle ratio, fitting each row of data, respectively, the mathematical relationship between the fault location and phase angle ratio can be obtained, finally realise DC line fault location by seeking average. Finally, a lot of different faults are simulated and analysed on the PSCAD platform to verify the effectiveness and robustness of the proposed method.