On the Use of Fuzzy Logic to Control Paralleled DC-DC Converters [chapter]

Bogdan Tomescu, Hugh F. Van Landingham
2002 Studies in Fuzziness and Soft Computing  
The objective of the thesis is to introduce a new fuzzy logic control application, develop the associated mathematical theory and prove the concept and its advantages through comparative simulation with existing, classical, methods. A stable fuzzy logic controller for the master-slave current sharing loop of a paralleled DC-DC system is presented that exhibits a considerably improved large signal performance over the presently employed, small signal designed compensators, both in terms of
more » ... response and control effort. Because of high system complexity, the present small signal designs are unable to give a good response for large load changes and line transients. Fuzzy logic, by dealing naturally with nonlinearities, offers a superior controller type, for this type of applications. The design uses a PID expert to derive the fuzzy inference rules, and simulation results show a good parameter insensitive transient response over a wide range load-step responses, e.g., from 25% to 75% of the nominal load. Current sharing control is formulated as a tracking problem and stability is ensured through adaptation or supervisory control on a Lyapunov trajectory. The technique benefits also from the heuristic approach to the problem that overcomes the complexity in modeling such systems and, hence, offers a practical engineering tool, amenable to both analog and digital implementations. iii Dedication This thesis is dedicated to my family: my parents, Marin and Maria, my grandparents, my uncle and aunt Milu and Tanţi and all other close ones, present and past, whose unconditional love made my journey possible. iv ACKNOWLEDGEMENTS I would first like to thank my family and friends for their warm support and patience during the research and writing of this thesis and throughout my career path. This includes all my friends, school and work colleagues and managers, both here in the US as well as from my early years in Europe, who encouraged my work and made valuable suggestions; their friendship is unforgettable. Next, I would like to especially thank my teachers, exam committee members and peers who inspired and guided me. My advisor, Prof. Hugh Foch VanLandingham, whose educational wisdom and understanding was my strongest support for this dissertation. He has shown me, once more, that management, teaching, research and fun can be all part of a good and balanced life. Prof. Fred C. Lee and associated CPES staff, for allowing me the exceptional opportunity of starting research and study at Virginia Tech -VPEC. In this regard, working also with Prof. Dushan Boroyevich significantly broadened my research interests.
doi:10.1007/978-3-7908-1783-6_4 fatcat:gnlutlh5obhlblkkxxgcnri6rm