基于主频零序功率的配电网故障选线新方法

在复杂的小电流接地系统发生单相接地故障时,现有的利用相关性选线的方法有时因判据裕度不足而产生误判.针对裕度不足的问题,本文提出了基于主频零序功率的配电网故障选线方法,其以主频零序功率作为特征量来选线,计算出各馈线所对应的主频零序功率综合相关系数,其中故障线路综合相关系数小于零,而健全线路综合相关系数大于零.大量仿真结果表明,此方法在一定程度上提高了选线判据裕度和选线准确率,且不受合闸角和故障电阻的影响.

A New Method of Fault Line Selection for Distribution Network Based on Zero Sequence Power of the Main Frequency

In the complex small current grounding system,when single phase earth fault occurred,the existing line selection methods of using the correlations maybe have problems because of insufficient criterion margin.For the lack of margin,this paper proposes a new method of fault line selection for distribution network based on the characteristic of zero-sequence power with main frequency.Then,we calculate the integrated correlation coefficient of zero sequence power with main frequency on every line.The integrated correlation coefficient of the fault line is less than zero,and the integrated correlation coefficient of the sound line is more than zero.The simulations show that the new method can improve the selection criterion margin and the accuracy of line selection,and it is not affected by the closed angle and fault resistance.