Soft-Transient Modulation Strategy for Improved Efficiency and EMC Performance of PFC Converters Applied to Flexible Induction Heating Appliances

摘要

Recent developments in domestic induction heating include flexible cooking surfaces that are demanding power factor corrector (PFC) converter for improved performance. In this paper, a soft-transient hybrid modulation strategy along with the converter control strategy is proposed to increase the efficiency and remove the zero-cross distortion, reaching a good balance between efficiency and EMC performance. The proposed modulation strategy works with zero voltage switching (ZVS) at constant frequency in the mains cycle decreasing the switching losses and avoiding the intermodulation noise. Besides, for the same reason, avoiding acoustic noise, this frequency can be variable in order to synchronize the load inverter and the PFC stage. A 3.7 kW prototype is implemented and the experimental waveforms and efficiency are measured to prove the feasibility of this proposal.