A Single-Phase Class-E Direct AC-AC Converter Using Conduction Mode-Exchanged Pulse Density Modulation for Induction Heating System

抄録

This paper presents a new prototype of a single-phase class-E direct ac-ac converter for induction heating applications. In contrast to the multi-stage and traditional single-stage power conversion systems, the proposed direct ac-ac converter not only simplifies the topology of power conversion, but also enhances the efficiency, soft-switching, and EMI performance, optimizing the overall system performance. This converter features a power control methodology utilizing the reverse conducting and reverse blocking modes of a bidirectional switch based on pulse density modulation, which is suitable for a wide range of soft switching and fixed frequency operations. The performance of the direct ac-ac converter is investigated by experiments using a 1.2kW/56kHz prototype, where the high-frequency load power regulation and power conversion efficiency are revealed as well as soft switching were verified. The practical effectiveness of the power converter and power control scheme are evaluated.