基于改进的HHT变换和信心度的配电网故障选线

摘要

Aiming at the problems that fault recognition rate is low and the reliability is difficult to make quantitative analysis of fault line identification method for power system, a fault line identification approach based on improved Hilbert-Huang Transform and identification confidence degree is proposed. Zero sequence current of each line can be decomposed by applying the improved HHT and the instantaneous phase angle and amplitude information of fault feature point are obtained, and fault line selection voting mechanisms are got by comparing phase and angle relationship. Feature points instantaneous amplitude is used to judge the credibility of the vote and define the identification confidence degree, and then the result of fault line identification is obtained. ATP/EMTP simulator is adopted to build five-feeder distribution network simulation model, with which different fault position, initial fault phase, earth resistance are simulated and the proposed method is validated. The simulation results show the proposed approach has high accuracy, shorten calculation time, and is not affected by the fault position, initial fault phase, and earth resistance.%针对现有的供配电系统的故障选线方法存在故障识别率不高和可靠性难以定量分析的问题，提出了一种基于改进的希尔伯特黄变换(HHT)和信心度的供配电系统故障选线的新方法。利用改进的Hilbert-Huang变换分解各个线路的零序电流，得到故障特征点的瞬时相角和幅值信息，通过比较相角关系制定故障选线投票机制。利用特征点瞬时幅值判断投票的可信性，并制定了合理的选线信心度，得到故障选线结果。在ATP/EMTP仿真软件中搭建了一个5馈线的配电网仿真模型，对不同的故障位置、过渡电阻和故障初始角进行仿真分析，对提出的方法进行了验证。验证结果表明，该方法可以正确快速地识别故障线路，极大缩短计算时间，并且不受过渡电阻、故障位置和故障初相角的影响。