Small signal modeling of a two-output high-frequency series-resonant induction heater

This paper proposes the analysis of a small-signal model of two-output high-frequency series-resonant induction heater. There are 2 control loops: power control by duty-cycle and frequency control to maintain the zero-voltage switching condition for all operating period. This prototype controls power by using 3 branches of full bridge series-resonant inverter: one branch for common control and others for each independently two-output whose power controlled by the asymmetrical voltage cancellation methodology. The small-signal equivalent circuit model is confirmed by PSpice with good agreement in simulation data.