Bounds and estimates on eddy current losses in soft magnetic composites

Abstract

Soft Magnetic Composites can be considered as a periodic pattern of circular fibers or spheres inside a matrix. In this paper, lower and upper bounds for eddy current (EC) losses are analytically deduced for these types of microstructures. Bounds are obtained from simple magnetic field averaging operations within the inclusions. The averaging manipulations rely on the determination of the effective permeability of the composite, which can be estimated using a homogenization strategy. Lower and upper estimates of EC losses are then obtained for more generic microstructures based on the definition of this effective permeability. Results are compared to Finite Element calculations. The model is then validated with experimental results from the literature.