Calculation of the transient temperature distribution in a TFIH device using the impedance boundary condition

This paper presents a method of alternately switched coils in transverse flux inductive heating devices (TFIH) and their finite element formulation in order to improve temperature distribution. In the present paper, the application of the boundary impedance method in eddy-current computation in thin conducting sheets is combined with the transient calculation of the resulting temperature distribution. In this nonlinear coupled electromagnetothermal problem the T&oarr;,Ω formulation is used to calculate the time-harmonic electromagnetic field. The Fourier´s thermal conduction equation is extended by terms for conduction, convection and radiation. In addition a quasi-steady state formulation for high switching frequencies is introduced