Phase Locked Loop for unbalanced utility conditions

A Phase-Locked-Loop (PLL) to deal with unbalanced utility conditions is introduced in this paper. The classical 3-phase PLL structure [1], [2] is studied first to gain a better understanding of the effect of the unbalance on the PLL [3]-[8]. Then, enhancements are proposed to improve the ability of the PLL to deal with unbalance. Finally, simulation and experimental results are presented.