基于磁场检测与多判据融合的架空线路接地故障定位方法

Single phase to ground fault location method of an overhead line based on magnetic field detection and multi-criteria fusion

针对当前配电网故障区段定位难的问题,提出了一种基于故障点前后磁场差异的故障定位新方法。首先,分析了杆塔处x轴与y轴磁场的分布及其与相电流的关系,同时考虑了三相导线排列差异与数据窗长短对磁场的影响。其次,通过故障点上下游x轴与y轴的磁场差异作为定位依据,分别从不同角度对双轴磁场进行相似度分析,由此构建5种定位新判据。最后,将5种定位判据通过D-S证据理论进行融合,将概率最大的区段判定为故障区段。所提方法综合了各判据的优势,克服了单一判据的适应性问题。通过对高阻故障、噪声干扰等多种工况进行仿真测试,验证了所提方法的有效性。

It can be difficult to locate the fault section of a distribution network.To help tackle this,a new fault location method based on the magnetic field difference between behind and ahead of fault point is proposed.First,the distribution of the x-axis and y-axis magnetic field at the tower and its relationship with phase current are analyzed.At the same time,the influence of the arrangement difference of three-phase conductors and the length of data window on the magnetic field is considered.Secondly,based on the magnetic field difference between the x-axis and y-axis upstream and downstream of the fault point,the similarity analysis of the biaxial magnetic field is carried out from different angles,and five new positioning criteria are constructed.Finally,the five location criteria are fused by D-S evidence theory,and the section with the greatest probability is determined as the fault section.Because of the advantages of each criterion,this method overcomes the adaptability problem of a single criterion.The effectiveness of this method is verified by a simulation test of a high impedance fault,noise interference and other working conditions.