Considerations on the design of a low power induction heating system

Abstract

The paper presents considerations useful to design low power induction heating system. Despite of the fact that an induction heating system exhibits nonlinearities, the paper uses a linear model in order to obtain an easier way of design. Thus, the series resonant inverter used in the induction heating system is modelled as a high frequency alternating voltage source. The same assumption is made on the load circuit that includes the induction coil and the ferromagnetic device subjected to the thermal processing. The model of the load is reduced to a linear resistive inductive circuit for a specific temperature, based on the simulation results offered by Flux 2D program. The program Flux 2D solve the thermal problem coupled with the eddy currents problem and the simulation results are used to derive the resistive and inductive effect of the load. In general, since the values of the equivalent resistance and inductance for the load are small, the authors take into account all the main parasitic elements of the electronic component parts that appear on the power path of the induction heating system. Paper comprises simulation and experimental results of a low power induction heating system that are in good agreement with the theoretical analysis.