Analysis and design method for parallel quasi resonant inverter in induction heating applications

In this paper, mathematical analysis of parallel quasi resonant (QR) inverter is performed, and a design method is proposed. The design method allows for quickly determining and evaluating required sets of quality factor, duty cycle, reflected load, normalized resonant frequency and state variable quantities in steady state. Consequently, it determines resonant tank parameters required for achieving zero voltage switching at desired values of peak switch voltage, peak resonant current, switching frequency, duty cycle and output power. An experimental induction heating system is implemented for 2.5 kW power rating and validates the analysis and design method.