Abstract

This paper proposes a control scheme composed by a linear control and a predictive algorithm with extended horizon for a three-level neutral-point-clamped (NPC) inverter topology for grid-tie photovoltaic applications. The proposed strategy is capable to balance the capacitor voltages at the DC link and to generate a sinusoidal current at the grid side with a unitary power factor. Differently to other approaches, the proposed scheme is easy to digitally implement, and does not need to retune the controller cost function weighting parameters, and reduces the computational effort. These advantages are added to the capability to operate photovoltaic modules at the maximum power point (MPP). Results validate the proposed control methods and the mathematical analysis.