Independent synchronization and control of three phase grid converters

This paper deals with independent control and synchronization for three phase grid connected converters. Two different implementations of phase-locked loop (PLL), i.e. the conventional three phase PLL denoted here as dqPLL and the single phase PLL are discussed. The difference between these two algorithms and their influence on the current reference are highlighted. Additionally, the implementation of two linear controllers, namely proportional-integral (PI) and proportional-resonant (PR) in order to obtain independent control is also discussed. Equations of the controllers in both cases are derived. Finally, simulation results are presented in each case