Geometrical approach for a predictive current controller applied to a three-phase two-level four-leg inverter

Current model predictive control for a grid-connected four-leg voltage source converter application is presented in this paper. The solution of the optimum criterion defined by predictive control is considered as the reference current. This current will be applied based on projections of the different current control vectors corresponding to the switches states. Geometrical properties of the predicted current projections are used to achieve a current control strategy operating at fixed switching frequency. A laboratory model of the four-leg converter and its load has been constructed and its performance has been tested through experiments.