A Fast Analog Controller For A Unity-Power- Factor AC/DC Converter

Unlike the slow control schemes associated with state-of-the-art UPF converters, where disturbances are attended to by control action taken only once per line cycle, the fast controller studied in this thesis makes use of the fact that control action can be exercised at a much faster rate (the switching frequency). As a result the fast controller, which is based on a large-signal periodically-varying model of a UPF power converter is able to achieve a much faster response time to disturbances. In addition, the fast controller may facilitate system improvements over conventional slow controllers such as the reduction of the output bus capacitance. A comparison is done between the conventional slow controllers and the fast controller. The robustness, stability and practical feasibility of the fast controller are examined. An analog implementation of a slow controller based on a large-signal model and the fast controller are presented. Thesis Supervisor: George C. Verghese Title: Professor of Electrical Engineering Thesis Supervisor: Steven B. Leeb Title: Assistant Professor of Electrical Engineering