Design and analysis of a single-stage three-leg resonant converter with PFM-ADC control

This article introduces an innovative three-load AC–AC converter topology and employs a hybrid control technique, incorporating pulse frequency modulation and asymmetrical duty cycle control. The innovation addresses inherent limitations in conventional induction heating systems. The proposed topology incorporates three legs, delivering power to multiple loads operating at distinct frequencies based on the unique physical characteristics of each load. The first converter leg maintains a fixed 50% duty cycle, optimising output through the implementation of PFM. Meanwhile, the remaining two converter legs operate by ADC to attain maximum power with independent power control for different vessels. The primary objective is to efficiently heat both non-ferromagnetic and ferromagnetic vessels. The PSIM platform simulation results are in close agreement with hardware results, validating the effectiveness of the proposed approach.