多频带分析的配电网单相接地故障选线

Detecting a fault line under a single-phase to ground of distribution network based on analysis of multi-frequency bands

针对多年来一直未得到根本解决的配电网单相接地故障选线问题,在分析故障选线现状和基于小波包选线方法的基础上,提出了多频带分析的选线方法。根据各线路暂态零序电流信号小波包分解的能量分布情况,提出对各线路选择能量集中的特征频带或组合特征频带;并根据故障线路和非故障线路暂态零序电流大小关系原理,比较各条线路特征频带或组合特征频带的暂态零序电流的能量以确定故障线路。现场数据和大量的Matlab仿真试验结果表明:该选线方法可以准确、可靠地实现配电网单相故障的选线。

Addressing the problem of choosing a fault line under single-phase to ground of distribution network, we presented a new criterion based on analysis of the development of fault line selection and a method using wavelet packets. The feature frequency band, or the combined feature frequency bands of each line, in which the transient capacity current was concentrated was chosen for maximum energy. Based on the principle that the transient capacity current＇s energy of the fault line was larger than the that of normal lines, fault line selection can be carried out adaptively by contrasting the energy of the transient capacity currents of all lines in each chosen frequency band. The simulation results and spot testing data shows the proposed method can detect the fault line in distribution networks precisely and reliably.