Simulation on Faulty Line Selection of Small Current Grounding System Based on Wavelet Transform

A method of single phase ground fault line selection in distribution networks with the application of wavelet transform technique is presented in this paper. The modulus maxima of the wavelet transform are extracted to determine the moment of the single phase ground fault. The magnitude and polarity of wavelet transforms, which belong to zero-sequence currents on all lines, are compared to each other at the same moment in order to identify the faulty line. Relative system models could be built and simulated in the environment of PSB in Matlab6.5. The following results can be indicated from the simulation: the method is not affected by fault conditions and can select the faulty line exactly. It can be applied in neutral non-grounding system and neutral extinction coil grounding system.