Robust LMI control of a buck-boost converter with low ripple propagation

This paper proposes a new robust control strategy to prevent the current ripple propagation into the dc-dc converter input, thus avoiding converter malfunctions. Concretely, we apply the new strategy to a buck-boost converter. The strategy is based on LMI control and use readily, fast convex optimization algorithms to obtain the solution. The control objective is maximizing the current disturbance rejection, where current ripple propagation and usual, prescribed dynamic performances are ensured. The paper describes the control design procedure, besides an illustrative example and simulation verifications. Simulation waveforms are in perfect agreement with objective function and performances constraints of the control design. That is, the current ripple propagation is almost zero and other prescribed constraints are satisfied.