An adaptive passivity — Based controller for a power factor precompensator

We develop in this paper a passivity-based control scheme for the feedback regulation of a class of switched power converters commonly addressed as power factor precompensators. In such applications, aside from load voltage regulation to a prespecified constant level, a vital additional control objective consists in keeping the input power factor close to unity. By forcing the converter input current to follow a sinusoidal reference signal which is in phase with the supplied voltage, one may approximately satisfy both control objectives within a single power stage. A further complication in our design is to consider the output load, usually modeled by a resistance, as unknown.