ADAPTIVE DYNAMICAL INPUT-OUTPUT LINEARIZATION OF DC TO DC POWER CONVERTERS - A BACKSTEPPING APPROACH

Dynamical adaptive regulation of pulse-width-modulation (PWM) controll ed power supplies is proposed using a suitable combination of average dynamical input-output linearization and the 'backstepping' controller design method. Nonlinear average models of de to de power supplies ar e not transformable to parametric pure nor parametric strict feedback canonical forms by means of parameter-independent state co-ordinate tr ansformation. A more direct approach is therefore proposed for impleme nting the fundamental ideas related to the so called 'non-overparametr ized' adaptive backstepping algorithm which avoids explicit transforma tions to the above mentioned canonical forms. Dynamical adaptive feedb ack controllers are developed for the regulation of the input-inductor current towards desirable constant values. The validity of the propos ed approach, regarding control objectives and robustness with respect to unmodelled, yet unmatched, and bounded stochastic perturbation inpu ts, is tested through digital computer simulations. (C) 1997 by John W iley & Sons, Ltd.