The fault location method and technology with high accuracy is essential for safe and reliable operations of power systems with long transmission lines. According to propagation characteristics of transient traveling wave under line-to-ground faults, a method of fault location for HVDC transmission lines based on the Hilbert-Huang transform (HHT) is proposed in this paper. Combining the advantages of Hilbert amplitude and instantaneous frequency, a new quantity PAF is proposed, so that the detection of the arrival time of the wave head is more accurate and reliable, and the locating accuracy is thus improved. The accurate model of Changji-Guquan ±1 100 kV UHVDC transmission system, including the frequency dependent phase model of transmission lines, is built in PSCAD/EMTDC, and the simulation results under different fault locations and different transition resistances indicate the significant precision and robustness of this method.

fault location,HHT,HVDC transmission lines,transient traveling waves