Study on line selection in non-effectively grounded system based on wavelet transform and Wiener filter

This paper, based on wavelet transform theory and Wiener filter technology, proposes a new method for single-phase fault line selection in small current system. This method selects the fault line by conducting wavelet transform on the steady zero-sequence current signals of the fault and removing the noise disturbance by Wiener filter and with the information after the noise is removed. In this method the useful information can be derived effectively from the signal interfered by noise, which overcomes the difficulty of the low SNR of the fault signals. The results of simulation with dynamic simulation and field record reveal that this method can meet the practical requirements.