Improved quasiresonant ZVS-PWM inverter with active voltage-clamped capacitor for high-frequency induction heating

This paper describes an advanced prototype of voltage-fed zero voltage soft-switching PWM resonant inverter with an active voltage clamped capacitor, which is used in the field of consumer power electronics put into practice for high-frequency high-power induction-heated appliances. This application-specific quasiresonant inverter using the latest generation IGBTs for soft-switching can regulate its output power under a principle of a fixed frequency ZVS-PWM strategy. Its operating principal and unique features are presented as compared with a conventional quasiresonant ZVS inverter, together with its power regulation characteristics on the basis of its computer-aided simulation and experimental results. The steady-state performances of this inverter developed for multiburner type induction-heated food cooking appliance induction-heated boiler and induction-heated fryer are discussed and evaluated from a practical point of view and evaluated in experiment.