State-of-the-art and future trends in soft magnetic materials characterization with focus on electric machine design – Part 1

Abstract

The first of this two-part article illustrates the state-of-the-art in soft magnetic materials characterization starting with very early developments and giving a retrospective view of research carried out in this field. One famous measurement setup is the Epstein frame, named after Josef Epstein. Around 1900, he published a German article about “The magnetic testing of laminated steel”. As it is highly likely interesting to researchers worldwide, the authors reconsidered his contributions in English language. Consequently, the most common measurement setups are introduced. Besides the Epstein frame, these are the single sheet tester and setups analyzing ring-shaped specimens. These setups allow for a 1-D characterization of the material, while it usually features anisotropic properties and cross-coupling of the magnetization axes. For this reason, 2-D and even 3-D setups are considered and presented here. This article provides a thorough introduction to the field of material characterization. It is the basis for modeling the material characteristics, which is presented in the second part, which also includes recent developments for considering manufacturing impact. It is of particular interest when dealing with mass-produced electric machines. Eventually, these articles shall constitute valuable references for both engineers new to this field as well as experienced researchers.

Iron Loss Calculation Methods for Numerical Analysis of 3D-Printed Rotating Machines: A Review

“…According to the standards, the tested samples need to be demagnetised before the measurement by applying an excitation that corresponds to more than ten-times the coercive field strength and gradually reducing it to zero. Using the measured voltages u 1 and u 2 , the magnetic field strength (H), magnetic induction (B), and power loss (p s ) can be calculated using the following equations [83]:…”