Output-feedback model predictive controller for voltage regulation of a DC/DC converter

In this study, an output-feedback model predictive controller (MPC) is presented for capacitor voltage regulation on the basis of a non-linear DC/DC converter. The proposed output-feedback MPC scheme is constructed by combining a state-feedback MPC scheme with a Luenberger-type observer. The proposed MPC does not carry out any online optimisation. Although the converter model is non-linear, the proposed observer gain ensures global exponential convergence of the state estimation errors. On the basis of this observer, an output-feedback MPC scheme is designed by certainty equivalence. It is also shown that the capacitor voltage globally converges to its reference while fulfilling input constraints. In order to eliminate the capacitor voltage offset error, a PI controller is employed in the outer loop. The experiment results demonstrate that the closed-loop performance is satisfactory despite the load resistance variations.