Abstract Aiming at the single phase to ground fault in small current grounding system, the transient component of zero sequence current of each line is complex, non-stationary, nonlinear, and the serious problem of noise interference, a new fault line selection method for small current grounding system is proposed. This method decomposes the zero sequence current of each line by EMD (empirical mode decomposition) algorithm, extraction of high frequency components, and using FIR filter to filter the high frequency component of zero sequence current of each line, selecting the most obvious effective band. Finally, by comparing the energy of the effective frequency band to select the line. The simulation results show that the method is accurate and reliable.
2017, Vol. 18 
