A Robust Nonlinear Control Scheme for a Sag Compensator Active Multilevel Rectifier Without Sag Detection Algorithm

In this paper, a robust nonlinear control scheme is proposed for the single-phase active multilevel rectifier (SPAMR) subject to voltage input sags. The scheme is based on the input-output model of the rectifier system combined with exact linearization achieved via generalized proportional-integral (GPI) control. The GPI controller provides enhanced robustness for the SPAMR against unexpected voltage sags and load changes. The main contribution of this paper resides on avoiding the need for voltage sags detection algorithms while improving the dynamic response of the SPAMR. Simulation and experimental results obtained on a 1-kVA SPAMR laboratory prototype are presented.