A novel DSP-based adaptive line synchronization system for three-phase utility interface power converters

Fast and accurate phase tracking is essential for the control of three-phase utility interface power converters. Conventional methods are compromises between the tracking errors and dynamic response. This paper proposes that the errors caused by phase unbalance and harmonics cannot be handled alone by the loop filter, whereas they can be minimized through advanced digital signal processing techniques. One solution is the adaptive line synchronization method presented in this paper. The results show superior performance in nonideal and fault conditions. The advantages are verified by simulation and experiments