A direct three-phase to single-phase AC/AC converter for contactless electric vehicle charger

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.