International Journal of Applied Electromagnetics and Mechanics - Volume 61, issue S1

Authors: Dou, Yu | Li, Yongjian | Zhu, Jianguo | Wang, Lixiang | Li, Angxuan | Zhang, Changgeng

Article Type: Research Article

Abstract: Accurate magnetic properties measurement of the magnetic materials plays an increasingly important role in electromagnetic devices design and optimization at high frequency. In this paper, the effects of high-frequency winding are mainly evaluated by theoritical and numerical analysis. Considering the skin effect in excitation winding, an equivalent model for the AC resistance of the copper foil winding is established, which determined the optimum thickness of copper foil under different excitation frequency. Then based on the finite element analysis, the segmented excitation windings with copper foil is designed, which can reduce the influence of high frequency and distributed capacitance. Moreover, the …segmented windings are wrapped around by ferromagnetic plates, which can restrain the fringing effect and ensure that the excitation frequency can be up to several kilohertz. Show more

Keywords: Distributed capacitance, skin effect, proximity effect, foil winding

DOI: 10.3233/JAE-190137

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S81-S88, 2019

Authors: Schauerte, Benedikt | Steentjes, Simon | Thul, Andreas | Hameyer, Kay

Article Type: Research Article

Abstract: The design of electrical machines requires accurate models for the estimation of locally occurring iron losses. For this purpose, varieties of iron-loss models are proposed. These allow one to calculate iron losses as a function of the unidirectional peak flux density B m and magnetization frequency f . Two-dimensional effects such as the materials’ anisotropy and its influence on the loss behavior are neglected in most of these models, e.g., the dependency of the iron losses on the spatial loci of the magnetic field. Nonetheless, these effects have a considerable influence on the local iron-loss distribution. Measurements under vector-field …conditions, which consider the flux loci and the magnetic anisotropy, along with modeling approaches to replicate the behavior are presented in this work. Show more

Keywords: iron loss modeling, vector hysteresis, magnetic anisotropy

DOI: 10.3233/JAE-191599

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S89-S96, 2019

Authors: Ako, Yuya | Takahashi, Yasuhito | Fujiwara, Koji | Jikumaru, Takehiro

Article Type: Research Article

Abstract: This paper investigates the influence of laminating process of permendur for improvement of power density motors. A permendur has a high stress sensitivity, however the influence of manufacturing process on the magnetic properties of a permendur has not been sufficently discussed. Therefore, we discussed the influence of manufacturing process by measuring the laminated and single sheet specimen and carrying out 3D analysis of a surface permanent magnet synchronous motor (SPMSM) using the measured magnetic properties of the laminated and the single sheet specimens. As a consequence, deterioration of magnetization property by laminating process does not affect significantly motor property in …motors having a wide gap. Show more

Keywords: Permendur, laminated specimen, mechanical stress

DOI: 10.3233/JAE-191149

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S97-S106, 2019

Authors: Youssef, Mohamad EL | Benabou, AbdelKader | Coorevits, Thierry | Van Gorp, Adrien | Clenet, Stéphane | Faverolle, Pierre | Mipo, Jean-Claude | Lavalley, Yannick | Lecuppe, Thomas

Article Type: Research Article

Abstract: An experimental approach is proposed to study the influence of the punching on the magnetic behavior of a stator core strips. Specimens of a non-oriented M330-A35 punched lamination sheet are picked up from a real manufacturing process. The proposed approach is based on the use of two types of specimens; one is a closed magnetic circuit while the second one is split into two parts. Magnetic measurements are performed on both types and compared with those made on specimens cut by WEDM which has a lower impact on the magnetic behavior. The specific purpose of this paper is to investigate …the impact of punching in presence of an air gap that exists in electrical machines between rotor and stator. Therefore a dedicated device, optimized by FEM simulations, is developed in order to account accurately the air gap. Show more

Keywords: Punching, magnetic characterization, stator

DOI: 10.3233/JAE-191291

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S107-S114, 2019

Authors: Matsubara, Ryo | Takahashi, Yasuhito | Fujiwara, Koji

Article Type: Research Article

Abstract: One of the main cause of acoustic noise from iron core in electrical machines is magnetostriction. However, good reproducibility of magnetostriction measurement cannot be expected due to its ppm-order value. To measure the magnetostriction accurately, it is required to clarify principal factors affecting the measurement accuracy. In this paper, a high-resolution method of measuring magnetostriction by means of an open-type single sheet tester equipped with double laser Doppler vibrometers is investigated. It is revealed that the odd components of a magnetostriction waveform should be removed as noises because the reproducibility of odd harmonic components is low. To improve the reproducibility, …the friction between a test specimen and a support plate installed under the specimen should be reduced. Furthermore, it is demonstrated that the developed measuring system can be also applied to magnetostriction measurement of Fe-based amorphous sheets. Show more

Keywords: Magnetostriction, electrical steel sheet, Fe-based amorphous sheet, laser Doppler vibrometer, single sheet tester

DOI: 10.3233/JAE-191148

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S115-S122, 2019

Authors: Higashigawa, Yuto | Takahashi, Yasuhito | Fujiwara, Koji | Aoyama, Masahiro | Akaki, Ryosuke

Article Type: Research Article

Abstract: Soft magnetic composites (SMCs) are magnetic materials obtained by compression molding of iron powders with an insulating coating and are suitable for a core of a motor having a complicated structure. It is known that its magnetic property is deteriorated by machining process due to the short circuit of the insulated layer on the material surface. In general, the acid etching treatment is performed to improve the degradation of the magnetic properties. In this paper, first the resistivity of the ring specimen of the SMC applying the acid etching treatment for a different immersion time is measured. Next, the magnetic …properties of the specimen are measured, and the effect of the machining process and the acid etching treatment on the magnetic and electric properties of the SMC is investigated. Show more

Keywords: Soft magnetic composite, acid etching, magnetic properties

DOI: 10.3233/JAE-191283

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S123-S129, 2019

Authors: Paltanea, Gheorghe | Manescu Paltanea, Veronica | Gavrila, Horia | Nemoianu, Iosif Vasile | Andrei, Paul Cristian | Ciuceanu, Radu Mircea

Article Type: Research Article

Abstract: Grain-oriented silicon iron alloys present an important magnetocrystalline anisotropy, which has a strong influence on the normal magnetization curve and the energy losses. The theory of Orientation Distribution Functions (ODF), applied in the case of materials presenting crystalline symmetry of body centered cubic structure and orthorhombic strip symmetry, is taken into consideration. The magnetocrystalline anisotropy is analyzed on JFE Steel Corp. commercial grade M-0H grain-oriented electrical steel, cut at different angles with respect to the rolling direction, ranging from 0° to 90° in equal steps of 15°. The accuracy of the ODF method is analyzed by taking into account firstly …three sets of experimental data, obtained for 0°, 45°, and 90°, then four sets, in the case of 0°, 30°, 60°, and 90° cut samples, and in the last case for all seven directions. The magnetic properties are predicted for any arbitrary direction and a relative error is analyzed, in each case, between the experimental and the numerical data. Finally, a proper number of experimental measurements was chosen, by considering a compromise between the magnitude of the error and the amount of experimental data. The samples were cut through mechanical punching, laser and travelling wire electro-erosion technologies. The normal magnetization curves and the energy losses were measured utilizing an industrial single strip tester (SST), at the frequency of 50 Hz. The model presented in the paper is a useful tool in the electric transformer cores’ design since every magnetic property could be predicted with an increased accuracy in the case of each angle. Show more

Keywords: Grain-oriented alloys, energy losses, orientation distribution functions, magnetocrystalline anisotropy, normal magnetization curve, punching, laser cutting, electro-erosion

DOI: 10.3233/JAE-198976

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S131-S139, 2019

Authors: Sim, Sunbo | Lee, Hoyong | Lee, Heejong | Lee, Jinyi

Article Type: Research Article

Abstract: Nondestructive examination and evaluation system for high pressure feed water heat exchanger tubes in nuclear power plant was developed. Differential-type bobbin coils made of copper wire are placed on both sides of GMR sensors arranged in a ring shape. If alternating current (AC) is applied to the bobbin coils, then an inductive current is occurred in circumferential direction of the tube to be examined. Under these conditions, eddy currents are generated around the defect. Because the time-varying magnetic field is distorted by eddy current that is generated around the defect, the shapes and dimensions of defect can be quantitatively evaluated …with cylindrical arrayed GMR sensors. The result was verified by the artificial defects fabricated in a small diameter heat exchanger tube. Show more

Keywords: High pressure feed water heat exchanger tube, BIGiS, GMR sensor, differential-type bobbin coil

DOI: 10.3233/JAE-191190

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S141-S150, 2019

Authors: Jastrzębski, Radoslaw | Jakubas, Adam | Chwastek, Krzysztof

Article Type: Research Article

Abstract: The paper considers the description of DC-biased minor loops with the GRUCAD model. The model is given in the form of a combination of nonlinear and ordinary differential equations, what bears resemblance to the well-known Jiles–Atherton formalism. However the model behaves in a qualitatively different way than the original Jiles’ proposal. The paper points out the differences between both approaches and presents the results of modeling for biased hysteresis loops of a Soft Magnetic Composite core.

Keywords: Biased hysteresis loop, GRUCAD model, soft magnetic composite

DOI: 10.3233/JAE-199557

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S151-S157, 2019