A novel algorithm for HVDC line fault location based on variant travelling wave speed

This paper presents a novel fault location algorithm based on variant travelling wave speed for HVDC (High Voltage Direct Current) transimission line. The algorithm effectively reduces the large fault locating errors, casuused by adopting consitent wave speeds, under off-design conditions. Fistly, it is illustrated how travelling wave speed varies with fault distance, and then how the variant speed effect fault locating accuracy is analysized. At last, the new algorithm is proposed to gurrantee the accuracy at any fault distance. The validity of the algorithm is verified by the relevant simulation results in EMTDC.