A model of the equivalent impedance of the coupled winding-load system for a domestic induction heating application

In this paper, an analytical model of the equivalent impedance of a planar circular induction system is derived. The considered induction system is composed of an n-turn planar winding loaded by a metallic material, and its equivalent impedance consists of the series connection of an equivalent resistor and inductor. The influence of the number of turns, the load electromagnetic properties, the frequency of the excitation currents and the geometrical dimensions is studied. Furthermore, the frequency-dependent resistance of windings, including both skin and proximity effects, is also included in the model. Validation of the proposed model is carried out through experimental measurements.