Novel constant frequency time ratio controlled series load resonant high frequency soft switching inverter

Series load resonant high frequency soft switching inverter with constant frequency power regulation function is presented. Proposed inverter supplies high frequency power to load by push pull operation which is provided by series load resonance and two ZCS switching cells as main switches. Main switching cell consists of reverse blocked active power switch and unidirectional lossless inductor snubber. Power regulation under constant output frequency is achieved by the PWM-ZVS auxiliary switch. The principle of ZCS operation using overlapping commutation and power regulation scheme are described. Test circuit is designed for actual induction heating application based on the numerical analysis. The characteristics of the power regulation with PWM provided by auxiliary switch in constant frequency are evaluated and verified experimentally. The soft switching operation for all switching devices is ensured through the high frequency induction heating application