Robust control of a DC-DC boost converter: H2 and H∞ techniques

Abstract

This study proposes H2 and H∞ robust controllers to be applied to a DC-DC boost converter operates in the continuous conduction mode (CCM) in a DC microgrid system. Towards this end, the DC-DC boost converter is modelled based on the state-space averaging method with possible uncertainty in its parameters and also considerable variation in the input voltage. By deriving the open loop perturbed transfer function, an unstructured uncertainty bound for the nominal system is presented. Next, two robust controllers (i.e., H2 and H∞) are designed to regulate the DC bus voltage in the presence of drastically variations in the input voltage, the input inductor, the output capacitor, and the DC bus load. Simulation results demonstrate that the proposed controllers are strongly robust against uncertainties and can be applied to a practical DC microgrid.