Improved 3D Electromagnetic Analytical Model for Translational Motion Induction Heater with Consideration of Finite Length Effects

In this paper we present an electromagnetic model to compute translational motion eddy current in a conductive plate of an induction heater. The movement of the plate in a dc magnetic field created by a PM inductor generates induced currents that are at the origin of a heating power by Joule effect. The magnetic field expressions due to the PMs is obtained by solving the three dimensional Maxwell equations by the method of separation of variables, using a magnetic scalar potential formulation and a magnetic field strength formulation. The motional eddy currents are computed and the finite length extremity effects are taken into account using the image's method. The proposed model takes into account the reaction field due to induced currents. The obtained results are close to those obtained from the 3D FE simulations and experiments.