Research and Application of Small Current Grounding Line Selection Device Based on Wavelet Packet Principle

Small current grounding fault frequently occurs in distribution network.In this paper,the design and installation of a new small current grounding line selection device is used to troubleshoot such fault.By using wavelet packet principle in the device,a dual processing chip of advanced reduced instruction set processor and digital signal processing chip with complex programmable logic device structure is used to achieve the combination of high efficiency and reliability.The device cannot be affected by the fault time and the compensation degree,and also has higher ability of restricting the transition resistance,which can achieve no dead zone fault line selection for providing good solution method of small current grounding fault.The research and application of the device in the practical operation can prove the superiority of line selection principle and the verification of line selection accuracy.