Extended frequency analysis of the loss under rotating induction excitation in Soft Magnetic Composites (SMC)

This article reports new results about the magnetic loss in Soft Magnetic Composites excited with rotating field. Indeed, these materials are very promising in electrical engineering applications, such as new topologies of electrical machines in which multidimensional induction loci are ubiquitous. Therefore, it has been provided an experimental characterization of a commercial SMC sample devoted to electrical machine applications, up to the kilohertz range, under alternating and circular induction loci. To this end, an experimental system has been designed and optimized for this kind of loss measurements, and the results have been subjected to the loss separation procedure, focusing the attention on the ratio between circular and alternating loss. The ratio between the excess loss obtained under rotating and alternating inductions of same peak amplitude has been found almost frequency independent. This result is then applied to successfully predict the loss under more complex induction loci, such as the elliptical case.