Galerkin-based sliding mode tracking control of non-minimum phase DC-to-DC power converters

Output voltage control of nonlinear DC-to-DC power converters is handicapped by the non-minimum phase character exhibited by these systems. The problem has been usually solved with indirect control strategies that work through the input current. In this article, we report a robust control methodology that uses Galerkin-based sliding manifolds, which use full state reference profiles and an estimate of the disturbed load parameter. The sliding surface incorporates a first-order Galerkin approximation of the input current that provides robustness to piecewise constant load perturbations by dynamic compensation: it allows on-line accommodation to the action of the load estimator. This results in high-accuracy tracking of periodic references at the output resistance of boost and buck-boost converters. Copyright © 2006 John Wiley & Sons, Ltd.