基于行波多路径的多端直流系统故障测距方法
Fault Location Method Based on Multi-path Traveling Wave in Multi-terminal DC System
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摘要: 针对多端直流系统中故障行波传播路径复杂、波速不确定性显著的问题,提出一种融合变分模态分解(Variational Mode Decomposition, VMD)与多路径行波信息的故障测距方法。首先,利用VMD对故障暂态信号进行自适应分解,从中提取表征行波突变特征的高频模态分量,实现波头时刻的高精度识别;其次,基于多端直流网络中行波多路径传播机理,构建与传播速度无关的多组测距方程,获得故障距离估计;最后,引入基于路径长度的反比加权策略对多路径结果进行融合校正。仿真结果表明,所提方法在不同过渡电阻及复杂拓扑条件下均表现出良好的定位精度与鲁棒性。Abstract: 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.
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