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

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.