The Study of Wavelet Analysis in Line Selection of Single-Phase Earth Fault in Medium Voltage Distribution Network

On the basis of detection fault line research about abstraction transient fault information in ground system, the fault line could be selected because of its high frequency transient current. After we discussed and analyzed the wavelet criteria of the detected signal in theory, the significant amplitude of correlation analysis in the selected fault line can be proved. We put forward a fault line identifying principle based on the difference of magnitude with wavelet transform. At the same time, the model of the selection fault line in ground system can be simulated by MATLAB. In the paper, some obviously detected fault line features and the extraction zero-sequence currents of wavelet transform amplitude used in route selection have been tested in medium voltage distribution network with small current grounding system.