Analysis of Loss according to the Ferromagnetic Materials of an Induction Heater for Electric Vehicles

Abstract

Electric vehicles (EVs) are required to have an independent heater system capable of heating the battery and the room. The heat sources of the induction heater are the copper and core losses. If an induction heater is generated from a high copper loss, the insulation level of the coil increases, which will cause a price increase. Therefore, it is important to increase the core loss generated from the work piece (WP, heating element). Ferromagnetic materials are mainly selected for the WP of induction heaters. The core loss is the sum of the hysteresis, eddy current, and excess losses generated from the ferromagnetic materials in a time-varying magnetic field. The hysteresis loss is proportional to the hysteresis loop. This loop is determined by the B-H curve, coercive force, and residual flux. The eddy current loss is determined by the induced voltage in the WP, and the excess loss is determined by the harmonics of the current.
System: In this paper, three ferromagnetic materials with different BH curves, residual magnetic fluxes, and coercive forces were selected. Also, the loss characteristics of the three ferromagnetic materials were analyzed through the modeling of the parallelogram hysteresis loop and finite element method (FEM) simulation. Finally, the analysis results were verified through experiments..