基于行波模态分解的特高压直流输电线路双端行波测距方法  

A double-terminal fault location method for UHVDC transmission lines based on traveling wave mode decomposition

作　　者：王洪彬[1,2] 周念成 王伟[2] 王强钢 于大川[1] 周丹莹 吕元正 WANG Hongbin;ZHOU Niancheng;WANG Wei;WANG Qianggang;YU Dachuan;ZHOU Danying;LÜYuanzheng(State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Chongqing 400044,China;State Grid Chongqing Electric Power Research Institute,Chongqing 401123,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400044 [2]国网重庆市电力公司电力科学研究院,重庆401123

出　　处：《电力系统保护与控制》2024年第1期109-120,共12页Power System Protection and Control

基　　金：国家自然科学基金项目资助(U22B6006);国网重庆市电力公司科技项目资助(2022渝电科技10#)。

摘　　要：基于晶闸管换流器的特高压直流输电系统(ultra-high voltage direct current based on line commutated converter,LCC-UHVDC)的故障定位算法对智能电网的安全稳定运行起着重要作用。针对长距离特高压直流输电系统故障测距方法精准度低、快速性差的问题,提出了一种基于变分模态分解法(variational mode decomposition,VMD)和Teager能量算子(Teager energy operator,TEO)的双端行波故障测距方法。首先,研究了LCC-UHVDC线路故障电压行波的传播特性。利用零模电压随线路传播衰减明显的特征,通过VMD算法提取采样点处零模电压行波的时频特性。针对VMD参数选择不当导致的模态混叠问题,利用K-L散度(Kullback-Leibler divergence)对提取的模态指标进行优化。然后采用TEO对分解后信号进行瞬时能量谱提取,精确标定波头到达时间,最后采用双端迭代测距法迭代求解故障距离。在PSCAD/EMTDC搭建±800 kV LCC-UHVDC仿真模型进行验证。结果表明,所提方法在不同故障位置、过渡电阻和故障类型下具有较强的鲁棒性。The fault location algorithm of an ultra-high voltage direct current(LCC-UHVDC)transmission system based on a thyristor converter plays an important role in the safe and stable operation of the smart grid.There are shortcomings of low accuracy and poor speed of fault location methods for long distance UHVDC transmission systems.Thus a double terminal traveling wave fault location method based on variational mode decomposition(VMD)and Teager energy operator(VMD)is proposed.First,the propagation characteristics of a fault voltage traveling wave in LCC-UHVDC lines are studied.Based on the characteristic that zero-mode voltage attenuates markedly with line propagation,the time-frequency characteristics of a zero-mode voltage traveling wave at a sampling point are extracted by a VMD algorithm.To solve the mode aliasing problem caused by the improper selection of VMD parameters,Kullback–Leibler(K-L)divergence is used to optimize the extracted modal indices.Then,TEO is used to extract the instantaneous energy spectrum of the decomposed signal,and the arrival time of the wave head is calibrated accurately.Finally,the fault distance is solved iteratively by the two-terminal iterative fault location method.The±800 kV LCC-UHVDC simulation model is established in PSCAD/EMTDC for verification.The results show that the proposed method has strong robustness with different fault locations,transition resistance and fault types.

关 键 词：特高压直流输电 变分模态分解 TEAGER能量算子 故障测距 电压行波 

分 类 号：TM75[电气工程—电力系统及自动化] TM721.1