基于VMD-HT算法的输电线路故障行波测距研究

Research on Traveling Wave Fault Location of Transmission Line Based on VMD-HT Algorithm

传统的双回线行波测距主要在参数对称的模型上进行研究,为解决工程实际中参数不对称同塔双回线的行波测距问题,提出了一种基于VMD-HT算法的故障测距方法。因参数不对称同塔双回线各线间、相间存在耦合,先将六相电流解耦得到6个独立电流模分量,对比分析后得到特征模量,再将特征模量进行VMD-HT变换,提取出故障行波波头初始到达线路两端的时刻,根据双回线测距公式算出故障位置。PSCAD和Matlab实验对比仿真表明,所提算法比三次B样条小波包变换和希尔伯特黄变换(HHT)算法具有更好的测距效果,模型由双回线推广至四回线,误差仍在允许范围内,验证了所提算法的正确性和普适性。

The traveling wave fault location of traditional double-circuit transmission lines are mainly studied on the model with symmetric parameters.In order to solve the problem of traveling wave fault location of doublecircuit lines on the same tower with asymmetric parameters in engineering practice,a fault location method based on VMD-HT algorithm was proposed.Due to the coupling between lines and phases of the double-circuit transmission lines on the same tower,the six phases’currents were first decoupled to get six independent current mode components,and the characteristic mode components were obtained after comparative analysis.Then,the characteristic mode components were transformed by VMD-HT to extract the initial arrival time of the traveling wave head arriving at both ends of the lines,and the fault location was calculated according to the double-circuit lines location formula.Comparison and simulation of PSCAD and Matlab experiments show that the proposed algorithm has better accuracy of fault location than cubic B-spline wavelet packet transform and Hilbert Huang transform(HHT)algorithm.The model is extended from double-circuit transmission lines to four-circuit transmission lines,and the error is still within the allowable range,which verifies the correctness and universality of the proposed algorithm.