Three-dimensional magnetic properties of soft magnetic composite material at different frequencies

Due to their intrinsic isotropic magnetic properties, soft magnetic composite (SMC) materials are applied in electrical machines in which the magnetic energy can be transported in three dimensions (3-D). However, in real applications, complicated magnetic properties such as anisotropy and nonlinearity, are found, in particular, at ahigh frequency range. This paper studies the 3-D magnetic properties of SMC materials under complicated magnetizations, such as circular, elliptical, and spherical excitations. The magnetic flux density vector B loci, magnetic field strength vector H loci, and core losses at magnetization frequencies ranging from 50-1000 Hz were measured and discussed using an improved 3-D testing system. Experimental results show that rotational core losses are greater than alternating losses at the same magnitude of flux density. In addition, rotational loss increases sharply around the saturation point, but is not observed in alternating loss. © 2011 American Institute of Physics