基于小波多尺度分析的输电线路直击雷暂态识别

研究和识别输电线路直击雷的暂态特征对研制基于暂态量的保护及提高其可靠性都具有十分重要的意义。该文首先从保护的角度对输电线路各类直击雷的特点进行深入的研究分析；通过小波变换对输电线路直击雷、短路故障等暂态信号的多分辨率分析，发现其暂态电流附加分量的能量分布特点反映了对应暂态过程的内在特征，可用以构成判据实现输电线路非故障性雷击暂态的准确、可靠识别，从而大大提高保护的抗雷电干扰能力。大量EMTP仿真计算验证了所提方法是正确、有效的。

IDENTIFICATION OF TRANSIENTS ON TRANSMISSION LINES CAUSED BY DIRECT LIGHTNING STROKES BASED ON MULTIRESOLUTION SIGNAL DECOMPOSITION

Study on transient characteristics of overhead transmission lines due to direct lightning stroke is significant to the development of transient based protection and its reliability improvement. The features of different kinds of direct lightning strokes and their effects on protection are discussed in the paper. Multiresolution signal decomposition is applied to analyze the transients on transmission lines generated by direct lightning strokes and by faults. Based on the differences in energy distribution of the transient current superimposed components, an approach is proposed to identify direct lightning strokes without faults correctly and reliably. It can be used to improve the reliability of transient based protection. The Electromagn- etic Transient Program (EMTP) simulations demonstrate the proposed approach correct and effective.