固有频率与行波时域定位结合的多端直流混合输电线路故障定位方案

为解决多端直流混合输电线路故障定位以及传统故障定位存在的波速影响的问题,本文对不同拓扑结构的线路提出定位方案。利用变分模态分解与Teager能量算子结合固有频率和行波时域定位确定了新型的定位方案,同时利用固有频率识别不同拓扑下的故障区域,并将Schavemaker电弧模型应用于弧光高阻故障影响分析中。PSCAD/EMTDC平台仿真结果表明,本文方案能准确定位不同区段的故障,综合的定位误差为+/-500 m。在方案稳定性分析中,结果表明在高阻、高噪声以及弧光高阻情况该方案仍能表现良好。最后,将本文方案与行波双端时域定位方案对比,本文方案可有效避免线路参数变化的影响。

Fault Location Scheme for Multi-terminal DC Hybrid Transmission Line Combined with Natural Frequency and Traveling Wave Time-domain Positioning

To solve the problem of the impact of wave speed in the fault location of multi-terminal DC hybrid transmission lines as well as in the traditional fault location,a location scheme for lines with different topological structures is put forward in this paper. By using the variational mode decomposition(VMD)and the Teager energy operator,a novel location scheme is determined with the combination of natural frequency and the traveling wave time-domain positioning. At the same time,the fault region under different topologies is identified by means of natural frequency,and the Schavemaker arc model is applied to the analysis of arc high-impedance fault(HIF)response. Simulation results on the PSCAD/EMTDC platform show that the proposed scheme can accurately locate faults in different sections,and the comprehensive positioning error is +/-500 m. In the stability analysis of the proposed scheme,results show that it can perform well even under conditions of high resistance,high noise and arc high-impedance. Finally,the proposed scheme is compared with the traveling wave dual-terminal time-domain positioning scheme,indicating that it can effectively avoid the influences of variations in line parameters.