A new power control scheme of class-D inverter for induction heating jar application with constant switching frequency

In this paper, a simple power control scheme for a constant frequency Class-D inverter with a variable duty cycle is proposed. It is more suitable and acceptable for high-frequency induction heating (IH) jar applications. The proposed control scheme has the advantages of not only wide power regulation range but also ease of control output power. Also it can achieve the stable and efficient zero-voltage-switching (ZVS) in whole load range. The control principles of proposed method are described in detail and its validity is verified through simulated and experimental results on 42.8 kHz IGBT for induction heating rated on 1.6 kW with constant frequency variable power.