Non-linear control and FCS — MPC applied to multi — Cell AFE rectifier with efficient behavior in steady state

One of the major drawbacks of Finite Control Set - Model Predictive Control (FCS - MPC), is the high switching frequency, besides a spread harmonic spectrum. Despite of this, the FCS - MPC provides excellent speed to changes of references and disturbances. In this work we present a control strategy based on FCS - MPC that allows a reduction of the switching frequency in steady state, increasing the efficiency of the converter from 91% to 94.4%. This is done by means of a converter status detection (stationary or transient). The above is implemented in a multi - cell AFE rectifier topology. The control strategy is performed by a master - slave loop, in each power cell. El outer loop manages the DC voltage link with nonlinear control, for ensure stable operation of the system. The inner loop controls the input current in each power cells through FCS - MPC. Simulations results show a correct performance of the proposed scheme.