Measurement and modelling of core losses of soft magnetic composites under 3D magnetic excitations in rotating motors

Soft magnetic composite (SMC) materials are especially suitable for construction of low cost high performance motors with three dimensional (3D) magnetic fields. The 3D finite element analysis (FEA) conducted in the design of a claw pole transverse flux motor (TFM) with an SMC core reveals very complicated B (flux density) loci in the core when the motor rotates. In order to understand and account for the effects of the patterns of B loci on motor parameters and performance such as core losses, a 3D magnetic property testing system was built for magnetic measurement on a cubic SMC sample. 3D rotational core loss models in SMC materials and rotating motors are developed and verified by the experimental results.