Design of a measurement system for investigating the magnetic characteristics of soft magnetic materials for non-sinusoidal periodic excitations

This article is about the design of a measurement system for measuring the iron losses in soft magnetic materials exerted by periodic flux density characteristics. The losses are due to hysteresis and eddy currents effects. The aim is to predict the iron losses which occur in electric machines. Common loss modeling techniques are derived by considering sinusoidal flux density characteristics. As nowadays highly-utilized machine designs with special winding topologies are employed, the periodic flux density characteristics in a big part of the ferromagnetic components are far off from being sinusoidal. Hence, the here presented measurement system and the associated control are especially developed for analyzing any periodic flux density characteristics. A further part of this article is dedicated to the comparison of state-of-the-art iron loss modeling techniques and measurement results. Several scenarios with different flux density harmonic magnitudes and frequencies are considered. It turns out that currently available loss modeling techniques show significant modeling errors for non-sinusoidal periodic flux density excitations. Thus, future work has to be on deriving more accurate models by considering their applicability for computer-aided engineering software.