Investigating the influence of material properties on the efficiency of an induction heating load transformer using FEM simulations

Abstract

The heating-coil and workpiece combination of an induction heating circuit can be seen as a transformer, i.e. the load transformer. It is common practice to neglect the influence of the magnetizing inductance, and therefore represent the load transformer with a series resistance and inductance. The efficiency will increase if the resistance of the workpiece increases according to this assumption. The validity of this assumption is investigated using finite element method simulations. The results showed that for materials with a high resistivity and relative permeability, e.g. the commonly used carbon steels, the magnetizing inductance should not be neglected. Experimental results are not presented due to the complexity of the problem.