Homogenization Approaches for Laminated Magnetic Cores Using the Example of Transient 3D Transformer Modeling
A specific issue in transformer modeling using the finite element method is the consideration of electric sheets or other laminated core materials which are used to reduce eddy currents. It would be impractical to explicitly model a large number of sheets as this would lead to a large number of elements and hence to unacceptable computational costs. Homogenization procedures overcome this problem. They substitute the laminated structure by a solid having nearly the same electromagnetical behavior. In our study, we have implemented several of them in a transformer model using COMSOL Multiphysics®. Simulation results obtained with the different homogenization approaches are compared to experimental test results. This reveals the accuracy and the application limits of the investigated homogenization approaches.