Multisampled hybrid model predictive control for pulse-width modulated systems

Abstract

This paper deals with the model predictive control (MPC) of pulse-width modulated (PWM) systems. Hybrid models that predict the switched behaviour of PWM systems are investigated in order to formulate control objectives such as minimising the non-linear distortion or the power losses as it is typically desired in many power electronics applications. To obtain tractable problems, the PWM system dynamics are approximated by hybrid models where the time is quantised. The switching constraints are modelled employing binary variables. Two MPC schemes with different receding horizon policies are investigated to solve the resulting MILP or MIQP at each sampling period. Applying the proposed multisampled hybrid model predictive control scheme to a buck converter system, it is shown that recomputing the optimal solution to the problem at regular intervals during the switching period provides a better rejection of disturbances.