Load adaptive modulation method for all-metal induction heating application

Induction heating (IH) load made from a non-ferromagnetic material have not been a target of an IH cooktop application, because a small resistance of the non-ferromagnetic material induces large resonant current on a series resonant converter. However, heating capability for various pot materials is essential to improve the functionality of IH products. In this paper, a load adaptive modulation is proposed to heat the pot of non-ferromagnetic and ferromagnetic materials. The proposed control method can change the magnitude of input voltage and operational frequency of power converter according to the pot resistance. The operational principle and design method are analyzed to implement the proposed control method. The validity is experimentally verified using a 2-kW prototype series resonant converter.