基于Prony相对熵的输电线故障综合定位方法

Composite Method of Transmission Line Fault Location Based on Prony Relative Entropy Theory

针对小电流接地系统发生单相接地故障时定位困难问题,提出一种基于Prony相对熵的输电线故障综合定位新方法。首先,对各检测点故障后T/4内的零序电流进行分段Prony拟合,提取暂态零序电流Prony主导分量;然后,求取相邻检测点的相对熵值,依据故障点同侧两点零序电流波形相似度高,而故障点两侧两点相似度低的特点,定位出故障区段;最后,在故障区段内,利用注入法进行故障距离测定。新方法综合了故障区段定位法和故障测距法的优点,既能减少上传的数据量,又不会丢失电流信号的主要特征,减轻了通信压力,提高了故障定位的精度。

In view of the transmission line fault location problem of single-phase grounding fauh in non-solidly ground- ed system, a composite method of fault line location based on Prony relative entropy theory is proposed in this paper. Firstly, piecewise Prony algorithm is used to fit the transient zero-sequence current signal of each detection point in the first T/4 cycle after fault occurs ; secondly, transient zero-sequence dominant components are extracted and the relative entropy values of adjacent detection points are computed ; then, the fault section is located by use of the feature that the transient zero-sequence current from the same side of fault point possesses high similarity while the opposite sides of fault point possesses low similarity. Lastly, the fault distance is computed based on signal injection method in the fault section. The composite method combines the advantages of fault section location and fault distance location. It needs less amount of data transmission, but at the same time, keeps the main feature of current. Thus it can reduces the burden of data communication and improves the precision of fault location, because.