Wavelet analysis and application on the technology detecting single phase-to-ground fault line for distribution network

The single phase-to-ground fault is the most frequent accident in distribution network. In order to achieve detecting fault line, the wavelet packet decomposition method was used in this paper. The first step is to analyze the transient characteristics of fault line and the wavelet packet decomposition of transient ground capacitive current. Then the energy method is used to extract the feature band, so judging fault line can be done by analyzing the relationship of amplitude and polarity with singularity and modulus maxima theory. In the end, the feasibility of this method is verified with MATLAB software.