Theoretical and numerical examination of equivalent resistances in zone-control induction heating system

When a workpiece is heated by eddy currents using a zone-control induction heating (ZCIH) system, there exists both inductance and resistance in the induction heating circuit. To efficiently control a ZCIH system, the detailed behavior of the self inductance and equivalent resistance of each coil and the mutual inductance and equivalent resistance between the coils should be clarified beforehand. This paper proposes the concept of the self- and mutual-equivalent resistances in the eddy current circuit and discusses the theoretical physical meaning and properties of these parameters. We also derive a theoretical formula for these parameters using a simple assumption and then examine their properties.