Effective versus standard Epstein loss figure in Fe-Si sheets

Ferrara, E.; Appino, C.; Rocchino, L.; Ragusa, Carlo Stefano; Barrière, Olivier de la; Fiorillo, F.

doi:10.3233/jae-172263

Cited by 2 publications

(7 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is noted that, by limiting the measurement to very short times (toff  ton) <<  ( = 49 s in Fig. 17) a straight line is a good approximation to (12) and we can retrieve P by (10). In the example reported in Fig.…”

Section: ) the High-flux Density 2d Magnetizermentioning

confidence: 76%

“…leff is found to be an increasing function of J0p in all the previous NO (0.5 T  J0p  1.5 T) and GO (1.0 T  J0p  1.8 T) alloys. It approximately ranges between 0.92 m and 0.98 m. Such an increase is understood and calculated in terms of Jp(x) profile and n(Jp) behavior [10].…”

Section: ) Epstein Framementioning

confidence: 92%

“…However, small deviations from uniformity of the magnetization inside the Epstein legs inevitably occur, impairing to some extent this conclusion. A detailed investigation on the evolution of effective magnetic field strength and polarization along the limbs, performed by means of localized H-and B-coils, on non-oriented, conventional grain-oriented (CGO) and high-permeability grain-oriented (HGO) sheets, actually shows non-negligible decrease of the polarization value Jp(x) across the limb length from center to corners in all materials [10]. Fig.…”

Section: ) Epstein Framementioning

confidence: 97%

“…In the limit Kext  0, this equation reduces to the linear relationship (10). The coefficient Kext is unknown, but it can be found by fitting the exponential decay of temperature observed after switch-off.…”

Section: ) the High-flux Density 2d Magnetizermentioning

confidence: 99%

“…They are therefore assumed as reference methods for the definition of the material quality in the specification standards. However, both Epstein and SST methods generate systematic contributions to the measurement uncertainty [9] and the obtained loss figures can be appreciably different from the "true" loss values, those provided by accurate local measurements of the effective magnetic field strength and the flux density [8] [9] [10]. An example concerning non-oriented and grain-oriented Fe-Si steel sheets is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

1-D and 2-D Loss-Measuring Methods: Optimized Setup Design, Advanced Testing, and Results

Barrière

Appino²,

Ragusa

et al. 2018

IEEE Trans. Magn.

View full text Add to dashboard Cite

Accurate measurements of magnetic losses in laminations are a prerequisite for their theoretical assessment, as well as for satisfying calculations of energy dissipation in engineering systems. The standardized and universally applied measurement method, used as a reference for the definition of the material quality in the specification standards, is based on the Epstein test frame magnetizer. Its success relies on the reproducibility of the performed measurements. Its limitations come, on the one hand, from cumbersome sample preparation and, on the other hand, from a certain divergence of the measured loss figures from the true loss figures. Similar systematic differences between measured and true loss values are also observed with the standard Single Sheet Tester method. In both cases, measurements under bi-dimensional induction are or cannot be envisaged. The design of new measurement setups and magnetizers overcoming the drawbacks of the Epstein and Single Sheet Tester methods and possibly becoming recognized Standards in the future is welcome, but challenging. This paper is devoted to a comprehensive discussion of the state of the art in the alternating and two-dimensional measurements of energy losses in soft magnetic materials for electrical applications. We will summarize, in particular, measuring solutions proposed in the current literature and we will discuss in detail recent developments achieved in the authors' labs regarding 1D measurements with compensated permeameters and 2D measurements at high inductions and high frequencies.

show abstract

Section: ) the High-flux Density 2d Magnetizermentioning

confidence: 76%

Section: ) Epstein Framementioning

confidence: 92%

Section: ) Epstein Framementioning

confidence: 97%

Section: ) the High-flux Density 2d Magnetizermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

1-D and 2-D Loss-Measuring Methods: Optimized Setup Design, Advanced Testing, and Results

Barrière

Appino²,

Ragusa

et al. 2018

IEEE Trans. Magn.

View full text Add to dashboard Cite

show abstract

Numerical modeling of magnetic induction in standard and triple Epstein frames considering cutting and staggering of sensor strips

Shilyashki

Pfützner²,

Trenner

et al. 2021

AIP Advances

View full text Add to dashboard Cite

For magnetic energy loss measurements on electric steel sheets, the Epstein tester (ET) is applied for 100 years. However, it suffers from unsolved problems, such as inhomogeneity of flux in the corners and even more of impact of sample cutting. As a matter of fact, a detailed study of flux distributions—as a pre-condition for improvements—has not been performed so far. In this work, we present the results of an advanced numerical 3D-magnetic anisotropic circuit calculation modeling. It considers most relevant impacts such as anisotropy, non-linearity, method of staggering, and in particular, consequences of sample cutting. According to the literature, the latter may yield material deterioration for edge zones of high width WDET. Here, we set WDET to 2.5 mm as a “coarse-cut” convention for practice, and we compare it with perfect “fine-cut” (W = 0). As a main result, deteriorated edge zones of standard ET strips of low width W = 30 mm yield a distinct concentration of flux along inner axial strip regions as a reason for strong local flux inhomogeneity and distortion. Consistent numerical comparisons predict that higher grades of magnetic homogeneity can be expected from wider sample strips, e.g., from a “Triple ET” with W = 90 mm. As a global conclusion, the Epstein frame represents a system of extreme 3D inhomogeneity, especially in the corners. The grade of inhomogeneity reaches its maximum in instants of high permeability. It may be strongly increased through coarse cutting. On the other hand, consequences of cutting can be decreased by increasing the strip width. This would allow for loss measurements using tangential field coils arranged in the central limb regions of TET.

show abstract

Effective versus standard Epstein loss figure in Fe-Si sheets

Cited by 2 publications

References 8 publications

1-D and 2-D Loss-Measuring Methods: Optimized Setup Design, Advanced Testing, and Results

1-D and 2-D Loss-Measuring Methods: Optimized Setup Design, Advanced Testing, and Results

Numerical modeling of magnetic induction in standard and triple Epstein frames considering cutting and staggering of sensor strips

Contact Info

Product

Resources

About