An adaptive fault line selection method based on wavelet packet comprehensive singular value for small current grounding system

In this paper, an adaptive fault line selection method based on the wavelet packet comprehensive singular value for small current grounding system is presented. First of all, wavelet packet decomposition is utilized to decompose transient zero sequence current (TZSC) of 2 cycles, then the comprehensive singular values are introduced to describe the fault information. Secondly, normalize the comprehensive singular values to compute the fault membership values. At last, according to the difference between the maximum membership value and the second maximum membership value, the selected fault line can be output. The simulation results show that the proposed method cannot be affected by fault line type, fault resistance and fault initial phase angle, and also has good anti-noise capability.