Affiliations: [a] Institute of Material Science and Engineering, China
Jiliang University, Hangzhou, Zhejiang, China | [b] Magnetic Measurements Laboratory (retired), PTB
Braunschweig, Braunschweig, Germany | Institute of Electrodynamics, Microwave and Circuit
Engineering, University of Technology, Vienna, Austria
Correspondence:
[*]
Corresponding author: J. Sievert, Institute of Material Science
and Engineering, China Jiliang University, Hangzhou, Zhejiang, China. E-mail:
johannes.sievert@t-online.de
Abstract: The standardized Epstein frame is a magnetic circuit for the
normative measurements of magnetic properties of electrical sheet steel
following the Wattmeter method. It was designed for convenient practical use in
industry rather than as an accurate physical representation of magnetic power
loss of the material. In principle, the Wattmeter method is based on the use of
a homogeneous ring sample as the magnetic circuit. The double overlapping
corners of the Epstein frame constitute a significant divergence from the
topology of the homogeneous ring, and, thus, are the source of a substantial
systematic error. This paper applies the simple method of summation of the
reluctances of the complete magnetic circuit (CRS) for the determination of
this error. The results for various types of electrical steel and for the
frequency range of 40 Hz to 100 Hz are considered. Results of variations of the
Epstein strip stacking scheme are also recorded.
