The Epstein frame is a well-known standardized system used to characterize soft magnetic materials. The users of this device usually consider that all the strips of a same grade placed in the frame are homogeneous, and they do not take into account the potential impact of the heterogeneity of the sheets on the quality of the characteristics deduced from the measurements. The aim of this paper is to quantify the individual heterogeneity of Epstein samples of the same FeSi grade (BH curve, losses, permeability), and to analyze, by both experimental and numerical ways, if the layout of the sheets can impact the Epstein core losses.
European Commission. Commission Regulation (EU) N°548/2014 of 21 May 2014 on implementing Directive 2009/125/EC of the European Parliament and of the Council with regard to small, medium and large power transformers, Off. J. Eur. Union, 2014.
2.
AppinoC., International comparison on SST and Epstein measurements in grain-oriented Fe-Si sheet steel, Int. J. Appl. Electromagn. Mech.48(2–3) (2015), 123–133.
3.
AhlersH.SievertJ. and QuQ.C., Comparison of a single strip tester and Epstein frame measurements, J. Magn. Magn. Mater.26(1–3) (1982), 176–178.
4.
NémethS.HargitaiC.SzaboL. and PappL., Field and loss measurements in Epstein frame and sheet testers, J. Magn. Magn. Mater.160 (1996), 183–184.
5.
XingY.ZhouS.ChenW.DongB.DongY. and WangJ., Epstein frame investigation on soft magnetic properties of Fe-based amorphous strips, Insight - Non-Destructive Test. Cond. Monit.63(10) (2021), 604–609.
6.
FreitagC.JoostC. and LeibfriedT., Modified Epstein frame for measuring electrical steel under transformer like conditions, ICHVE 2014 - 2014 Int. Conf. High Volt. Eng. Appl. (2014), 2–5.
7.
SievertJ., New data on the Epstein to single sheet tester relationship, Prz. Elektrotechniczny (7) (2013), 5–7.
8.
SievertJ., The measurement of magnetic properties of electrical sheet steel - Survey on methods and situation of standards, J. Magn. Magn. Mater.215–216 (2000), 647–651.
9.
de la BarrièreO.AppinoC.RagusaC.FiorilloF.LobueM. and MazaleyratF., 1-D and 2-D loss-measuring methods: Optimized setup design, advanced testing, and results, IEEE Trans. Magn.54(9) (2018), 1–15.
10.
AntonelliE.CardelliE. and FabaA., Epstein frame: How and when it can be really representative about the magnetic behavior of laminated magnetic steels, IEEE Trans. Magn.41(5) (2005), 1516–1519.
11.
ParentG.PeninR.LecointeJ.P.BrudnyJ.F. and BelgrandT., Determination of specific losses in the limbs of an Epstein frame using a three Epstein frame methodology applied to grain oriented electrical steels, Sensors16(6) (2016).
12.
MarketosP.ZurekS. and MosesA.J., A method for defining the mean path length of the epstein frame, IEEE Trans. Magn.43(6) (2007), 2755–2757.
13.
SundariaR.DaemA.HemeidaA. and SergeantP., Effect of different cutting techniques on magnetic properties of grain oriented steel sheets and axial flux machines, IECON Conf. 20191 (2019), 1022–1027.
14.
SzymuraS. and ZawadaA., Effect of cutting operation on core-loss of grain-oriented silicon iron, J. Mater. Sci.16 (1981), 3194–3198.
15.
PaltaneaG.ManescuV.NemoianuI.V.GavrilǎH. and AndreiP.C., Influence of cutting technologies on the magnetic anisotropy of grain oriented electrical steel, in: 2017 Electric Vehicles International Conference, 2017.
16.
LeuningN.SteentjesS. and HameyerK., Impact of grain size distribution on the magnetic deterioration due to cutting of electrical steel sheets, J. Magn. Magn. Mater.497 (2020), 166080.
17.
BaliM.De GersemH. and MuetzeA., Epstein frame measurement based determination of original non-degraded and fully degraded magnetic characteristics of material submitted to laser cutting, in: 2015 IEEE Energy Convers. Congr. Expo. ECCE 2015, 2015, pp. 6096–6101.
18.
YanawatiY., Nominal power loss on 0.35 mm and 0.50 mm thicknesses of non-oriented steel sheets using Epstein tester frame, in: 2013 IEEE 7th International Power Engineering and Optimization Conference (PEOCO2013), 2013, pp. 600–602.
19.
IEC. Magnetic materials – Part 3: Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of a single sheet tester, Geneva, 2010.
20.
IEC. Magnetic materials – Part 2: Methods of measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstein frame, 2008.
21.
MechlerG.F. and GirgisR.S., Magnetic flux distributions in transformer core joints, IEEE Trans. Power Deliv.15(1) (2000), 198–203.
22.
PeninR.ParentG.LecointeJ.P.BrudnyJ.F. and BelgrandT., Impact of mechanical deformations of transformer corners on core losses, IEEE Trans. Magn.51(4) (2015), 5–9.
23.
BertottiG., General properties of power losses in soft ferromagnetic materials, IEEE Trans. Magn.24(1) (1987), 621–630.
