A half-bridge series resonant inverter for induction cookers using a novel FPGA-based control strategy

Abstract

Asymmetrical pulse width modulation (APWM) with frequency tracking control strategy is proposed for half bridge series resonant inverter for induction cookers, by which inverter is operated at zero-voltage-switching (ZVS) over wide load range. The FPGA-based full digital control system construction and operation are described. Steady state characteristics, such as normalized output power, turn-off current and average current through switches, are calculated. Some design considerations including selection of snubber capacitor, determination of dead time, ZVS boundary and presetting of phase-locked loop (PLL) are discussed. Finally, experiment results are given