Hilbert-Huang变换在T型输电线路故障定位中的应用

Applied research of improved Hilbert-Huang transform in fault location of T-type transmission line

根据T型线路故障时各端测得的行波波头到达时刻来建立判别矩阵D,以此来判断故障支路。将单端与双端定位方法相结合,解决了T型线路交汇点附近(小于1 km)故障支路难以判断的问题。针对Hilbert-Huang变换过程中经验模式分解(EMD)处理数据时可能造成端点效应和模态混叠,提出使用白噪声聚类经验模型分解(EEMD)以及一种改进的EMD算法来代替,用分解前后信号的总能量来评估几种分解过程的准确性。定位结果表明EEMD以及改进的EMD算法在T型线路故障定位中的定位精度高于EMD算法,能满足定位的输电线路的定位精度要求。

The time matrix F according to the transient traveling wave＇s arrival time to each ends could be used to establish the distinguish matrix D. The fault slip could be determined. Taking the single-end and double-end location methods into connection, the problem of the fault slip near the point of intersection （less than lkm） could be determined. In the process of the Hilbert-Huang transform, empirical mode decomposition （EMD） may result in the end effect and modal aliasing when processing data. Ensemble Empirical Mode Decomposition （EEMD） was proposed. The EMD was substituted by an improved EMD. The accuracy of the decomposition processes according to the total energy of the signal before and after the decomposition was assessed. Positioning results show that EEMD and improved EMD are better than EMD in the fault location of T-type transmission line, and the positioning accuracy can meet the requirement of fault location.