Controller design method for a cascaded converter system comprised of two DC-DC converters considering the effects of mutual interactions

This work analyzes the stability conditions of a cascaded converter system comprised of two dc-dc converters and proposes a new controller design procedure for the two converters considering their dynamic interactions. First, it introduces a single converter small-signal model and its mathematical representation and derives the required transfer functions from it. Next, it uses the single converter model to reach the cascaded converter system model and derives the principal equations for analyzing stability and controller design. Finally, it proposes a new design method based on the analysis of the derived equations. The simulation and experimental results are also provided, which verify the design procedure.