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Aiming at the superior control performance, systematic development approach, physical intuitiveness, and straightforward digital implementation, this dissertation extends the particular set of physics-based (or model-based) controller design (PBCD) techniques from inverters and machine drives to three-phase AC-DC power converters, in particular, to boost and buck rectifiers.
The dissertation assembles the PBCD techniques into a framework, extends the framework to the boost/buck rectifiers, and verifies the resulting controls through theoretical analysis, simulations, and Control Hardware-In-The-Loop (CHIL) experiments. The framework includes several previously unreported features that allow control design for non-minimum-phase systems, operating point (OP)-adaptation, and tuning without time scale separation, among others. Theoretical/CHIL experimental comparative evaluation has been carried out for a boost rectifier with resistive load, showing the PBCD advantage over the conventional control methods in various control metrics, such as command tracking, disturbance rejection, and closed-loop pole sensitivity to parameter variations.
Apart from the improved control performance, the PBCD framework exhibits a systematic development approach and physical insight. To showcase the systematic development, the dissertation develops and verifies the automated companion tool for PBCD synthesis - a function that automatically synthesizes the complete PBCD control structure provided the plant model. To verify the tool, a control structure has been synthesized for buck rectifiers with resistive/constant DC voltage loads. The control synthesis tool is envisioned to support the adoption of the developed framework in research and industry settings by streamlining and accelerating PBCD control development.
To showcase physical insight, for the unity power factor boost rectifier with resistive load, the dissertation establishes the PBCD equivalence to the modern linear control techniques such as state-feedback and structured H∞ control. Findings herein can serve as an intuitive connection of industry practices to these modern controls.
Overall, the dissertation presents PBCD as a well-balanced control design framework for three-phase boost/buck-type AC-DC power converters. For the considered boost rectifier case studies, PBCD achieves good dynamic performance, enables DC-link minimization, and physically interprets state-feedback and structured H∞ controls, all while preserving systematic development, physical intuitiveness, and straightforward firmware implementation.