Joint punching and frequency effects on practical magnetic characteristics of electrical steels for high-speed machines
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- 作者：A. Kedous-Lebouca ; O. Messala ; oualid.messal@g2elab.grenoble-inp.fr ; A. Youmssib
- 关键词：Electrical sheets ; Frequency ; High-speed electrical machines ; Losses ; Magnetic characterization ; Modeling ; Punching impact ; SiFe ; CoFe
- 刊名：Journal of Magnetism and Magnetic Materials
- 出版年：2017
- 出版时间：15 March 2017
- 年：2017
- 卷：426
- 期：Complete
- 页码：658-665
- 全文大小：2219 K
- 卷排序：426
文摘
Mechanical punching of electrical steels causes a degradation of their magnetic characteristics which can extend several millimeters from the cut edge. So, in the field of industrial applications, particularly that of small electrical machines, the stator core made of rigid and thin teeth would be subject to more losses. Thus, this topic of the effect of punching has to be submitted to further deep characterization and development in order to give some insight into the different mechanisms. In this framework, this paper evaluates the combined effect of punching and frequency on the magnetization curve and iron losses in thin SiFe and CoFe soft magnetic sheets. These alloys are typically suitable for the manufacture of high-speed electrical machines used in on board applications (aircraft power generators, automotive, etc). Two SiFe alloys and a CoFe alloy have been investigated. First, different rectangular samples of variable width (15, 10, 5, 3 mm) have been industrially punched. Then, a dedicated magnetic characterization has been made, using basically a mini-Epstein frame. Measurements have been performed from 50 Hz to 1 kHz and from 0.3 T to near saturation. Both rolling and transverse directions have been considered. Finally, a first attempt to predict the degradation due to the punching is presented. A useful description of the magnetic permeability as a function of B and f is given and the degradation parameters are estimated based on the knowledge of the reference permeability.