Novel method for synchronization to disturbed three-phase and single-phase systems

An Autoadjustable Synchronous Reference Frame for extracting the positive-sequence fundamental component of the voltage in the point of common coupling is proposed in this paper. It operates suitably under unbalanced and distorted input voltages, with no steady state error in amplitude, phase and frequency tracking. The dynamic response of the method in case of frequency or amplitude variations is good, achieving the steady state in only two cycles of the fundamental period. The method allows a simple adaptation for being used in single-phase systems too. Simulation and experimental results are presented to test the novel method.