Modeling of Anisotropic Laminated Magnetic Cores using Homogenization Approaches

A specific issue in transformer modeling using the finite element method is the consideration of electric sheets or other laminated core materials which are commonly used to reduce eddy currents. Instead of explicitly modeling the geometry of every single core sheet material homogenization procedures can be applied. They substitute the laminated core structure for a virtual bulk material which has the same outer dimensions and nearly the same electromagnetic behavior. In our study, we have implemented a selection of different homogenization approaches in an inductor model in COMSOL Multiphysics. Simulation results thereby obtained are compared to those from models with explicitly modeled core structure and also to experimental test results. This reveals the accuracy and the application limits of the investigated homogenization approaches.