Fault Location Method Based on Multi-path Traveling Wave in Multi-terminal DC System

For the problems of complex fault traveling wave propagation paths and significant uncertainty in wave velocity in multi-terminal DC systems, a fault distance measurement method integrating variational mode decomposition (VMD) and multi-path traveling wave information is proposed. Firstly, VMD is utilized to adaptively decompose the fault transient signal, extracting the high-frequency mode components that represent the wave mutation characteristics, achieving high-precision identification of the wavehead time; Secondly, based on the multi-path propagation mechanism of traveling waves in multi-terminal DC networks, multiple sets of distance measurement equations independent of propagation speed are constructed to obtain the fault distance estimation; Finally, a inverse weighting strategy based on path length is introduced to fuse and correct the multi-path results. Simulation results show that the proposed method exhibits excellent positioning accuracy and robustness under different transition resistances and complex topologies.