基于多频带分析的自适应配电网故障选线研究

该文应用小波包具有良好的领域分频特性，以适当频率带宽对配电网发生单相接地故障后备条线路的暂态零序电流进行分解，得到其在不同频段下的输出。按照能量最大的观点确定各条线路暂态电容电流分布最集中的特征频段，并根据故障线路暂态电容电流的极性与非故障线路不同的原理，通过比较所有线路在各自特征频段下的小波包分解系数的极性来自适应地实现故障选线。理论分析及大量的ATP仿真结果表明：该选线方法可以准确、可靠地实现配电网单相故障的选线。

STUDY ON ADAPTIVELY CHOOSING FAULT LINE UNDER SINGLE-PHASE TO GROUND FAULT BASED ON ANALYSIS OF MULTI-FREQUENCY BANDS

Applying the good property of frequency division of wavelet packets, each lines transient zero sequence current, which appears in the distribution networks occurring a single phase to ground fault, is decomposed to obtain the outputs of different frequency bands in this paper. The characteristic frequency band of each line, in which the transient capacity current is most concentrated, is chosen according to the view of maximum energy. Based on the principle that the transient capacity currents polarity of the fault line is contrary to the ones of normal lines in its characteristic band, the fault line choosing can be adaptively carried out by contrasting the polarities of the wavelet packets decomposition coefficients of the transient capacity currents of all lines in each characteristic frequency band. The results of theoretical analysis and ATP simulations show that the proposed method can choose out the fault line in distribution networks exactly and reliably.