Decoupling of Currents in Travelling Wave Induction Heating

Abstract

Travelling wave induction heating (TWIH) suffers from severe interference between the coils, which significantly reduces its efficiency. A strategy for decoupling the currents in TWIH is presented, based on the anti-series or anti-parallel connection of several inductors. The study investigates the coupling effect in terms of amplitude and phase shift as functions of current and frequency, respectively, including resonance behavior. In addition, the effects of deviations of the inductor properties are analyzed. Measurements indicate that the strategy produces very good results, almost eliminating the coupling effect, increasing the efficiency, and simplifying control. Simulated and measured results of the heating pattern are compared and efficiency values and power densities are presented.