Selection of Soft Magnetic Composite Material for Electrical Machines using 3D FEA Simulations

This paper analyzes the impact of Soft Magnetic Composite (SMC) material properties on the losses and efficiency of electrical machines and presents a method for SMC grade selection. Three electric machines are simulated using 3D Finite Element Analysis (FEA): radial flux, axial flux and transverse flux Permanent Magnet (PM) machines. The core losses in SMC parts are calculated using a hybrid method that includes the joule loss of the induced 3D eddy currents in the SMC stator core as well as geometry-independent losses calculated by analytical equations based on toroid tester data. The results show that the selection of SMC material solely based on one given material property such as, permeability, core loss or resistivity results in suboptimal motor performance. On the other hand, the simulation results show that an SMC material with balanced properties achieved the highest efficiency and best overall performance. Finally, an SMC core with balanced properties was developed and tested in a toroidal measurement setup.