Design and Qualitative Robustness Analysis of an DOBC Approach for DC-DC Buck Converters With Unmatched Circuit Parameter Perturbations

A disturbance observer-based control (DOBC) approach is proposed in this paper for control design and qualitative robustness analysis of PWM-based DC-DC buck power converters. A disturbance compensation gain is constructed for the composite control algorithm to cancel the unmatched uncertainties in the output voltage channel. Rigorous criterion is provided to show the quantitative robustness between controller parameters and circuit uncertainties. The DOBC approach delivers not only a promising disturbance rejection performance but also a superior property of tracking performance recovery. The feasibility and efficiency of the proposed approach is validated by experimental results based on LabVIEW real-time control test setup.