Model Predictive Control of an UPS using periodic invariance

This paper deals with the Model Predictive Control of Uninterruptable Power System(UPS) using two level converter. The controller uses the d-q plane model of the system to predict the behavior of the state including output voltage at each sampling time. An equilibrium state and corresponding equilibrium inputs for the given reference output voltage is determined from the system model. Using the derived equilibrium input values, invariant sets for the deviation from the equilibrium state is defined with respect to the pertuation on the equilibrium inputs. A receding horizon control strategy is developed based on the invariant sets.