DYNAMICAL ADAPTIVE PULSE-WIDTH-MODULATION CONTROL OF DC-TO-DC POWER CONVERTERS - A BACKSTEPPING APPROACH

Adaptive regulation of pulse-width-modulation (PWM) controlled DC-to-D C power supplies is proposed using a suitable combination of dynamical input-output linearization and the 'backstepping' controller design m ethod. A nominal parameter, input-dependent, state coordinate transfor mation of the average PWM converter models leads to a type of pure par ameter feedback canonical form associated with the Fliess generalized observability canonical form of such average models. A backstepping de sign procedure can then be immediately devised which leads to a dynami cal adaptive regulation scheme for the generation of the stabilizing d uty ratio function. The validity of the proposed approach, regarding c ontrol objectives and robustness with respect to unmodelled, yet unmat ched, and bounded stochastic perturbation inputs, is tested through di gital computer simulations.