Series resonant inverter with active snubber circuit for improved efficiency operation applied to domestic induction heating

Efficiency is a key design parameter for domestic induction heating systems. To achieve this aim, resonant converters featuring soft switch on transitions are commonly used. In this paper, a cost-effective active snubber circuit is proposed to optimize the switch off transition. This allows the converter to operate under a wide range of operating conditions, with optimized asymmetrical control strategies, and allows the designer to select slower power devices with optimized conduction parameters. The proposed circuit has been tested with a 4-kW series resonant inverter.