Quantitative Evaluation of Induction Efficiency in Domestic Induction Heating Applications

Efficiency of electromagnetic energy transference in coupled pot-inductor systems of induction cooktops is analyzed. The influence of different parameters such as pot properties, number of turns of the windings, frequency of the currents, cable types, and ferrite arrangements is studied by means of an analytical model. The proposed model is a combination of two independent models corresponding to the loaded planar coil impedance and the cable losses, respectively. The two models are related using the global magnetic field of the system. The analysis reveals that it is not possible to experimentally determine induction efficiency by measuring unloaded and loaded winding impedances. In this paper, we propose a practical method to obtain the induction efficiency and compare the results with theoretical predictions. Quantitative results corresponding to different pot materials, frequencies, type of cables, and ferrite arrangements are also presented.