A Homogenization Technique to Calculate Eddy Current Losses in Soft Magnetic Composites Using a Complex Magnetic Permeability

Soft magnetic composites (SMCs) are a promising alternative to laminated steel in many electrical engineering applications. This is largely owing to their low level of eddy current (EC) losses. The electromagnetic behavior of SMC in electromagnetic devices cannot be easily predicted using standard numerical techniques, such as the finite-element (FE) method, mostly due to the computational cost required to model the material microstructure. Another difficulty lies in the high contrast between matrix and inclusion properties. In this paper, we propose a homogenization strategy to estimate EC losses in SMC. It is based on the calculation of a homogenized complex magnetic permeability. The imaginary part reflects the EC losses, while the real part describes the standard magnetic permeability. The complex permeability approach is applied to SMC with fiber or spherical inclusions. EC losses obtained from the complex permeability approach are compared with FE calculations, with very satisfying agreement.