A Direct Three-Phase to Single-Phase AC/AC Converter for Contactless Electric Vehicle Charger

摘要

This paper proposes an attractive direct line-frequency three-phase to a higher frequency single-phase AC/AC converter for a contactless electric vehicle charger. It removes a DC-link capacitor of a conventional AC/AC converter but has a smaller number of bi-directional switches than a matrix converter. It operates using injection and free-oscillation modes based on a zero-current switching mechanism. Circuit descriptions including a topology, commutations and a modulation strategy are discussed using some illustrations and diagrams. An on-off control is used to simplify control of resonant current. Simulation results to study some effects due to different coupling factor and load are then presented to show converter's performance and capabilities in contactless power transfer.