scholarly journals On a magnetic skin effect in eddy current problems: the magnetic potential in magnetically soft materials

2021 ◽  
Vol 72 (4) ◽  
Author(s):  
Victor Péron ◽  
Clair Poignard
Keyword(s):  
Eddy Current ◽  
Skin Effect ◽  
Soft Materials ◽  
Magnetic Potential ◽  
Magnetically Soft Materials

scholarly journals A Novel Approach on the Unipolar Axial Type Eddy Current Brake Model Considering the Skin Effect

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1561
Author(s):  
Hery Tri Waloyo ◽  
U Ubaidillah ◽  
Dominicus Danardono Dwi Prija Tjahjana ◽  
Muhammad Nizam ◽  
Muhammad Aziz
Keyword(s):  
Correction Factor ◽  
Eddy Current ◽  
High Speed ◽  
Skin Effect ◽  
Actual Condition ◽  
Average Error ◽  
Low Speed ◽  
Novel Approach ◽  
Calculation Results ◽  
Braking Torque

The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analytical and 3D modelling, the amount of braking torque at a low speed was found to have an average error for the equation using a correction factor of 1.78 Nm, while after repairing, a value of 1.16 Nm was obtained. For the overall speed, an average error of 14.63 Nm was achieved, while the proposed equation had a small difference of 1.79 Nm. The torque difference from the calculation results of the proposed model with the measurement value in the experiment was 4.9%. Therefore, it can be concluded that the proposed equation provided a better braking torque value approach for both low and high speeds.

scholarly journals Development of a magnetic force microscopy for magnetically soft materials

2009 ◽  
Vol 165 ◽  
pp. 012036 ◽  
Author(s):  
Hikaru Nomura ◽  
Tatsuro Nagayama ◽  
Daisuke Yokota ◽  
Ryoichi Nakatani
Keyword(s):  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Soft Materials ◽  
Force Microscopy ◽  
Magnetically Soft Materials

Investigation of magnet segmentation techniques for eddy current losses reduction in permanent magnets electrical machines

2015 ◽  
Vol 34 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Belli Zoubida ◽  
Mohamed Rachid Mekideche
Keyword(s):  
Genetic Algorithm ◽  
Finite Elements ◽  
Eddy Current ◽  
Permanent Magnets ◽  
Skin Effect ◽  
Electrical Machines ◽  
Design Parameters ◽  
Finite Elements Analysis ◽  
Eddy Current Losses ◽  
Content Type

Purpose – Reducing eddy current losses in magnets of electrical machines can be obtained by means of several techniques. The magnet segmentation is the most popular one. It imposes the least restrictions on machine performances. This paper investigates the effectiveness of the magnet circumferential segmentation technique to reduce these undesirable losses. The full and partial magnet segmentation are both studied for a frequency range from few Hz to a dozen of kHz. To increase the efficiency of these techniques to reduce losses for any working frequency, an optimization strategy based on coupling of finite elements analysis and genetic algorithm is applied. The purpose of this paper is to define the parameters of the total and partial segmentation that can ensure the best reduction of eddy current losses. Design/methodology/approach – First, a model to analyze eddy current losses is presented. Second, the effectiveness of full and partial magnet circumferential segmentation to reduce eddy loss is studied for a range of frequencies from few Hz to a dozen of kHz. To achieve these purposes a 2-D finite element model is developed under MATLAB environment. In a third step of the work, an optimization process is applied to adjust the segmentation design parameters for best reduction of eddy current losses in case of surface mounted permanent magnets synchronous machine. Findings – In case of the skin effect operating, both full and partial magnet segmentations can lead to eddy current losses increases. Such deviations of magnet segmentation techniques can be avoided by an appropriate choice of their design parameters. Originality/value – Few works are dedicated to investigate partial magnet segmentation for eddy current losses reduction. This paper studied the effectiveness and behaviour of partial segmentation for different frequency ranges. To avoid eventual anomalies related to the skin effect an optimization process based on the association of the finite elements analysis to genetic algorithm method is adopted.

Magnetic Anisotropy of Nanocrystalline HITPERM-Type Alloys and its Correlation with Application

2009 ◽  
Vol 154 ◽  
pp. 169-173
Author(s):  
Jarosław Ferenc ◽  
Maciej Kowalczyk ◽  
Tatiana Erenc-Sędziak ◽  
Xiu Bing Liang ◽  
Gabriel Vlasák ◽  
...  
Keyword(s):  
Soft Materials ◽  
Process Selection ◽  
Soft Magnetic ◽  
Predominant Role ◽  
Magnetoelastic Anisotropy ◽  
Magnetic Cores ◽  
Magnetoelastic Properties ◽  
Crystallisation Process ◽  
Magnetically Soft Materials ◽  
Magnetic Hardening

Structure as well as magnetic and magnetoelastic properties of nanocrystalline (Fe,Co)-(Hf,Zr)-Cu-B alloys (HITPERM-type) were investigated in order to find out which factors are responsible for the magnetic hardening of these magnetically soft materials. Magnetoelastic anisotropy, caused by the presence of cobalt, was found to play the predominant role in the observed increase of coercive field. On this basis, guidelines on chemical composition and crystallisation process selection were suggested for two fields of application: soft magnetic cores and sensors or actuators cores.

Sign in / Sign up

Export Citation Format

Share Document