A Line Selection Method Based on Capacitor Switching by Complex Wavelet

When the single-phase to ground fault occurs, the initial current traveling wave of fault line and normal lines will change steeply, if the capacitor of bus isn´t considered. When the capacitor of bus switches, the initial current traveling wave of normal line will change slightly, but that has no effect on the fault line which still keeps abruptly change. Based on that, this paper proposes a new line selection method to identify the fault line by using the capacitor switching strategy when the fault occurs. Though complex transform, many disadvantages of real wavelet transform can be avoided. This method can enlarge the differences between normal line and fault line, and reinforce the detection accuracy in a great extent. The simulation tests verify the efficiency and sensitivity of the proposed algorithm.