| The reliability of distribution network plays a vital role in the economic development. With the larger size of the distribution network and cable lines increased, the arc caused by single-phase ground fault is more difficult to extinguish. So the most of distribution network use the method of resonant grounding, although this method reduces the ground current and easy to extinction the arc, the accuracy of fault line selection device faces a great challenge. Therefore, it is necessary to study fault transient zero sequence current when resonant grounded power occurs single phase grounding, in order to accurate select fault line and improve power system's stability.Considering the problem of difficult to selection the fault line in the resonant grounded system, proposed three new methods based on improvements wavelet entropy for selection. In the basis of analysis variation for transient ground fault current zero-mode, added real-time amplification features to the wavelet energy entropy can more obvious the characterization failure point, made correlation analysis to the wavelet time entropy can more prominent the different characteristics between fault line and non-fault line, made cumulants to the wavelet singular entropy overcome the problem of fault detection not obvious by the large transition resistance grounding, then improve the sensitivity and the anti-jamming capability to the signal analysis. The D-S evidence theory integration the three improved wavelet entropy obtained a more reliable result. Simulation shows that the method can accurately determine the fault line.Finally, software of single-phase resonant power system fault line selection is designed, the paper uses LabVIEW to make interface, The interface designed Visual C++, and using MATLAB carries on backstage operation processing. The device can display the results by digital and graphic. It not only has a good interface, but also can improve the efficiency of software development.
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