基于小波包分析的配电网故障选线新方法

New Criterion of Faulty Line Detection for Distribution Networks Based on Wavelet Packet Analysis

分析了小电流接地系统中基于小波包分析的故障选线方法的优势和不足,提出了基于小波包分析的故障选线新方法。首先对采样的零序暂态电流信号做增强处理,然后利用小波包分析方法进行故障选线。基于上述原理研制了配电网接地选线装置,给出了装置的硬件结构及软件流程,试验结果表明,该方法有效地提高了小电流接地选线的准确性。

This paper analyses the deficiencies and advantages of the faulty line detection method based on wavelet packet analysis in indirectly grounding power system and presents a novel faulty line detection method based on wavelet packet analysis. First the zero sequence transient current signal sampled is enhanced,and then the signal enhanced is decomposed by using wavelet packet analysis to realize faulty line detection. A device based on the principle above for detecting grounded feeder is developed. The block diagram of its hardware and the flow of its software are given. The experiment results indicate that this method has effectively raised the accuracy of the faulty line detection in indirectly grounding power system.