| Synergetic control theory, which first emerged in 1994, is applied to DC converter-based power systems. This dissertation research represents the first application of a critical concept of synergetic control theory, the continuous time subset, to a system of parallel-connected buck converters affected by piece-wise disturbances. As the work shows, the theory is capable of handling the most challenging features of these systems, such as nonlinearity, multi-connectivity, high-dimensionality and coordination. The new synergetic control strategies that are presented here account for nonlinearity of the system, control interaction of paralleled units and coordinate their operation.; Synergetic control theory introduces invariant-manifold-based control design procedure, resulting in analytical control laws that contract the system state space and account for system nonlinearities and limitations. These control laws ensure global or semi-global stability of the closed loop system and improve the system's transient response and performance.; The capability of synergetic control theory to account for nonlinearities in the system is shown on examples of one- and two-buck converter systems that feed constant power loads. Next, the theory's capability to control interaction among paralleled buck converters and its capability for optimizing system efficiency is shown on systems containing an arbitrary number of parallel connected buck converters that feed resistive loads and a power distribution system containing eight paralleled buck converters, respectively.; Through simulation, it is shown that synergetic control, compared to feedback linearization, has better transient response and robustness against parametric variations, and that it also nullifies output voltage and current sharing errors. New general synergetic control strategies and stability conditions are presented for an active and a droop current sharing methods. To optimize system efficiency for droop current sharing, the number of converters operating in parallel was changed. The simulation shows that this optimization improves efficiency of the system under light loads.; Ultimately this research enables creation of control strategies for dynamic power management at different levels of a DC electric power distribution system, and improved operational flexibility and reliability of paralleled converter based power systems. |
