SWITCHED SLIDING-MODE CONTROL FOR ZCS SERIES-RESONANT AC/DC CONVERTER

Abstract

A combined buck and boost zero-current-switched series-resonant AC/DC converter for DC output voltage regulation with a high power factor is proposed. The proposed single-phase AC/DC converter enables a zero-current switching operation of all the power devices, allowing the circuit to operate at high switching frequencies and high power levels. A dynamic model for this AC/DC converter is developed in a discrete-time domain and an analysis for the internal operational characteristics is explored. Based on this analysis, a switched sliding-mode control technique is investigated with its advantages over the other type of current-control technique are discussed. With the proposed control techniques, unity power factor without current overshoot and a wide output voltage range can be obtained.