ZVZCS SRI Guides Optimal Use of Copper and Core for Air-Cooled Nanocrystalline Transformer for Induction Heating

Abstract

In induction heating applications, active and passive power components play important roles for proper functioning of the power controllers. For suitability study, the characterization of active power components is well defined and documented. Characterization of capacitors is also well defined. They are commercially available as well. High-frequency power magnetic components, such as transformers and inductors, are not readily available. For better power density and reliable operation of controllers, their qualitative evaluation is necessary. The parametric set to define the suitability of finished high-frequency magnetic components is large and wide, have multiple and complex heat sources. For input materials, multiple choices are available. Two main ingredients in high-frequency magnetic components are the magnetic core and litz-wire conductor. This article, using inherent features of ZVZCS SRI topology, explores practical methods to validate the optimal design of the high-frequency power transformer for induction heating applications. The method is able to evaluate the usable current density of the litz wire conductors as well as the upper limit of usable flux density of nanocrystalline cores.