Analysis and design of QFT-based robust control of a boost power converter

The application of quantitative feedback theory (QFT) to design robust controller for a DC-DC boost converter operating in continuous conduction mode (CCM) is investigated in this paper. The controller is designed to provide good attenuation of the load disturbances in spite of practical limitations on the achievable closed-loop performance (i.e. right-half-plane zero) and in the presence of other design constraints including closed-loop tracking and robust stability. A prefilter is subsequently designed in order to improve the transient and steady state control responses. Tracking control characteristics are analyzed through computer simulation for a peak-current-mode (PCM) controlled boost converter in order to demonstrate the effectiveness of the proposed control methodology.