Magnetic energy losses of silicon iron (SiFe) sheets are determined by the standardized methods of single sheet tester (SST) or Epstein tester (ET). The ET is much more compact and can be applied in a large range of frequency. However, it suffers from several sources of systematic errors. The most severe one is given by the magnetic cores flux distribution that shows a strong degree of inhomogeneity. This fact is highly evident. However, it never has been investigated in detail so far. Herein, we report results of a 3-D modeling, performed by magnetic anisotropic circuit calculation (MACC), considering non-linearity in connection with anisotropy, for both non-oriented (NO) steel and grain-oriented (GO) steel. The results reveal substantial differences of the corresponding flux distributions. NO steel proves to be characterized by high homogeneity of induction in rolling direction in the middle sections of the four limbs. However, the four corners show strong inhomogeneity in instants of low global induction, while a transition to more balanced flux arises at peak magnetization. On the other hand, this transition is much less pronounced for GO steel. As a conclusion for the evaluation of losses, a distinction is needed for the two different types of material.

中文翻译：

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Epstein 测试仪中瞬时磁通量分布的 3D MACC 建模

硅铁 (SiFe) 片的磁能损失由单片测试仪 (SST) 或爱泼斯坦测试仪 (ET) 的标准化方法确定。ET 结构更紧凑，可以应用在很大的频率范围内。然而，它受到多种系统误差来源的影响。最严重的是磁芯通量分布，表现出强烈的不均匀性。这个事实非常明显。然而，到目前为止，它从未被详细研究过。在此，我们报告了通过磁各向异性电路计算 (MACC) 执行的 3-D 建模结果，考虑了与非取向 (NO) 钢和晶粒取向 (GO) 钢的各向异性相关的非线性。结果揭示了相应通量分布的显着差异。事实证明，NO 钢的特点是四肢中间部分在轧制方向上的感应均匀性高。然而，四个角在整体感应低的瞬间表现出强烈的不均匀性，而在峰值磁化时出现向更平衡通量的过渡。另一方面，这种转变对于 GO 钢来说不那么明显。作为损失评估的结论，需要区分两种不同类型的材料。