The primary objective of evaluation of eddy-current losses is to provide a guide for optimized design of tractive transformer. It is not sensible to directly create the detailed laminations of a transformer core for analyzing the eddy-current field because of sophisticated modeling procedure and incredible computational cost. As a result, in this article, a series of original formulas to describe the equivalent electromagnetic parameters of multilevel-circle-section wound core under various frequencies, including anisotropic conductivity and permeability, are proposed to serve for finite-element analysis, on which the core model is considered to be a continuum with homogeneous material property. The experiment of core losses on practical wound core with the characteristic of multilevel-circle section is taken to verify the availability of the proposed model, where the modified extrapolation method is applied to obtain the eddy-current components separated from total core losses. Finally, there are satisfactory precisions on simulated results of eddy-current losses at a wide range of frequency and magnetic flux density; hence, this homogenization method is effectively applicable for engineering. This article can also provide reference for analysis of the other electromagnetic problems in tractive power supply equipment.

中文翻译：

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一种用于估计多级圆截面卷芯涡流损耗的齐次模型

涡流损耗评估的主要目的是为牵引变压器的优化设计提供指导。由于复杂的建模程序和难以置信的计算成本，直接创建变压器铁芯的详细叠片来分析涡流场是不明智的。因此，本文提出了一系列原始公式来描述不同频率下多级圆截面卷芯的等效电磁参数，包括各向异性电导率和磁导率，用于有限元分析。核心模型被认为是具有均质材料特性的连续体。通过对具有多级圆截面特征的实际绕线铁心进行铁损实验，验证了所提模型的有效性，其中应用修正外推法得到从总铁损中分离出来的涡流分量。最后，在较宽的频率和磁通密度范围内，涡流损耗的模拟结果具有令人满意的精度；因此，这种均质化方法有效地适用于工程。本文也可为分析牵引供电设备中的其他电磁问题提供参考。在较宽的频率和磁通密度范围内，涡流损耗的模拟结果具有令人满意的精度；因此，这种均质化方法有效地适用于工程。本文也可为分析牵引供电设备中的其他电磁问题提供参考。在较宽的频率和磁通密度范围内，涡流损耗的模拟结果具有令人满意的精度；因此，这种均质化方法有效地适用于工程。本文也可为分析牵引供电设备中的其他电磁问题提供参考。