UDE-based robust voltage control of dc-dc power converters

A method of linear robust controller design based on Uncertainty and Disturbance Estimator theory is proposed in the paper for nonlinear uncertain single input single output systems with external disturbances and applied to output voltage control of a unidirectional universal buck-boost converter. The controller forces the system to maintain nearly nominal performance through the whole range of operation space by quickly estimating and canceling the uncertainties and external disturbances. Despite the non-triviality and relative complexity of the method, the resulting controller structure is simple, allowing low cost low part count analog implementation. Extended simulation results are presented to demonstrate the effectiveness of the proposed method.