International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Shibataki, Takuya | Takahashi, Yasuhito | Fujiwara, Koji

Article Type: Research Article

Abstract: It is desirable that the waveform of induced voltage 𝜐b in the B-coil is substantially sinusoidal when magnetic properties of electrical steel sheets are measured. To realize a sinusoidal 𝜐b , the IEC standards specify that its form factor FF should be controlled within 1.11 ± 0.01 (IEC, Magnetic materials.---Part 3: Methods of Measurement of the Magnetic Properties of Magnetic Sheet and Strip by Means of a Single Sheet Tester, 60404-3, 2010; Matsubara K. et al., Acceleration technique of waveform control for single sheet tester, IEEE Trans. Magn., 31 (6): 3400-3402, 1995). However, the condition is not sufficient …because a non-sinusoidal waveform can also give FF = 1.11. Ideally, the distortion factor DF 𝜐b of 𝜐b should be equal to 0. Therefore, this paper discusses the influence of the DF 𝜐b on magnetic properties of electrical steel sheets measured with a single sheet tester. As a result, it is confirmed that the iron loss is directly proportional to the distortion factor of induced voltage in the B-coil. Therefore, the distortion factor should be specified relating accluracy of the iron loss measurements. Show more

Keywords: Distortion factor, electrical steel sheet, magnetic properties, single sheet tester

DOI: 10.3233/JAE-190924

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. S1-S10, 2019

Authors: Li, Yongjian | Zhang, Kai | Zhang, Changgeng | Yue, Shuaichao | Yang, Qingxin

Article Type: Research Article

Abstract: Accurate magnetic properties measurement of the silicon steel plays an increasingly important role in electromagnetic devices design and optimization. However, with the 2D circular and elliptical magnetization, which usually exist in the corner joint of three-phase transformer and behind the teeth of AC rotating machines, there is lack of experimental data result in the difficulty of reaching high frequency induction at kilohertz range. In this paper, a novel two-dimensional (2-D) magnetic tester with ultra-thin silicon steel sheets is designed and analyzed. In order to improve the measurement precision, a combined B -H sensing structure is designed to avoid the …local inhomogeneity of magnetic field distribution caused by drilling holes. Both the alternating and 2D rotating magnetic properties of non-oriented silicon steel M210-35A are systematically measured at a wide range of frequency and magnetic flux density. Show more

Keywords: Ultra-thin silicon steel, 2-D magnetic properties, high frequency, composite magnetic sensor

DOI: 10.3233/JAE-191147

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. S1-S7, 2019

Authors: Owzareck, Michael | Lüning, Kai | Parspour, Nejila

Article Type: Research Article

Abstract: A reliable simulation and design of inductive components requires knowledge of the core material’s magnetic properties. Usually no such data is available for medium frequencies, thus magnetic properties have to be measured. IEC 60404-10 suggests to measure magnetic properties in a frequency range between 400 Hz and 10 kHz by means of an Epstein frame, which however requires high apparent power (IEC 60404-10:2016. Magnetic materials – Part 10: Methods of measurement of magnetic properties of electrical steel strip and sheet at medium frequencies ). Furthermore the mean magnetic path length has to be known to measure the magnetic field strength. …Standards such as IEC 60404-10 state a constant length of 940 mm which in reality depends on multiple factors, including frequency and peak flux density. Therefore errors will inevitably be made (J. Sievert, The measurement of magnetic properties of electrical sheet steel – survey on methods and situation of standards, Journal of Magnetism and Magnetic Materials 215-216 (2000), 647–651; P. Marketos, S. Zurek and A.J. Moses, Method for defining the mean path length of the Epstein frame, IEEE Transactions on Magnetics 43 (6) (2007), 2755–2757). Singe sheet testers, which are not as popular as Epstein frames, however have some advantages over the Epstein frame (IEC 60404-10:2016. Magnetic materials – Part 10: Methods of measurement of magnetic properties of electrical steel strip and sheet at medium frequencies ; J. Sievert, The measurement of magnetic properties of electrical sheet steel – survey on methods and situation of standards, Journal of Magnetism and Magnetic Materials 215-216 (2000), 647–651; D. Miyagi et al., Development of measurement system of magnetic properties at high flux density using novel single-sheet tester, IEEE Transactions on Magnetics 45 (10) (2009), 3889–3892; M. De Wulf et al., Design and calibration aspects of small size single sheet testers, Journal of Magnetism and Magnetic Materials 45 (10) (2003), 70–72). To decrease the apparent power demand when measuring Epstein frame sized samples as well as to reduce systematical errors, an optimized single sheet tester, also called single strip tester or SStT, has been developed for medium frequencies and high flux densities. Show more

Keywords: Single strip tester, electrical sheet steel, medium frequencies

DOI: 10.3233/JAE-191285

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. S1-S7, 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. Pre-press, no. Pre-press, pp. S1-S10, 2019

Authors: Manescu (Paltanea), Veronica | Paltanea, Gheorghe | Andrei, Paul Cristian | Hantila, Ioan-Florea | Grumeza, Catalin | Bucata, Victor

Article Type: Research Article

Abstract: The static B-H relationship is a very important parameter, used in the characterization of magnetic materials. In the paper is presented a novel laboratory equipment that has an “8” figure shaped magnetic circuit, which is made from a negligible hysteresis soft alloy. The experimental set-up consists of two DC coils, in which the currents i 1 and i 2 are set, to obtain a null value of the magnetic flux in the median yoke that has an “O” shaped figure, with two AC coils. A stationary magnetic field inverse problem is solved, starting with a couple of …DC currents (i 1 , i 2 ) and a piecewise linear normal magnetization curve is computed. The nonlinearity of B-H relationship is treated by polarization fixed-point iterative method, while for each iteration the Green function is engaged. The static magnetization curve is compared, with the B-H relationship measured, using a high precision metrological device, on a toroidal sample made from the same material. Show more

Keywords: B-H relationship, green function method, inverse magnetic field problem, polarization method, soft magnetic composites

DOI: 10.3233/JAE-198972

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. s1-s10, 2019

Authors: Jamil, Meryeme | Benabou, Abdelkarder | Clénet, Stéphane | Arbenz, Laure | Mipo, Jean-Claude

Article Type: Research Article

Abstract: Claw pole machine performances are strongly related to the electromagnetic properties of ferromagnetic materials. These properties are impacted by the manufacturing processes, in a heterogeneous way, as well as by the thermal behavior of the machine and the mechanical stress distribution. Due to the complexity of CP geometry, extracted samples cannot respect the dimensions prescribed in international standards of electric and magnetic measurements. This paper proposes a specific methodology to characterize the electrical conductivity and the magnetic behavior of massive parallelepiped specimens extracted from different locations of a CP rotor.

Keywords: Claw pole rotor, electromagnetic properties, mini SST, four point measurement, correction factor, FE simulation

DOI: 10.3233/JAE-191491

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. S1-S8, 2019

Authors: Jastrzębski, R. | Jakubas, A. | Chwastek, K.

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. Pre-press, no. Pre-press, pp. S1-S7, 2019

Authors: Shutta, Yusaku | Ako, Yuya | Takahashi, Yasuhito | Fujiwara, Koji | Kitao, Junji | Yamada, Masaki

Article Type: Research Article

Abstract: This paper investigates the influences of the grade, the alignment direction and magnetization ratio of Nd–Fe–B sintered magnet on its conductivity and AC loss to achieve further high-efficiency of permanent magnet synchronous motors. As a result, it is confirmed that the difference in grade had little effect on the conductivity and AC loss. The difference in conductivity is not caused by the magnetization ratio. Furthermore, the influence of hysteresis loss and skin effect varies depending on the magnetization ratio.

Keywords: Nd–Fe–B sintered magnet, conductivity, anisotropy, AC magnetic loss, motor

DOI: 10.3233/JAE-190821

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. S1-S10, 2019

Authors: Dyer, Christopher | Gkaliou, Kyriaki | Anderson, Philip | Harrison, Christopher | Eaton, Mark | Hall, Jeremy

Article Type: Research Article

Abstract: Although polymer nanocomposites have attracted much attention, their bulk application is limited due to poor manufacturing scalability while maintaining organized microstructures. Active assembly of nanoparticles using magnetic fields is a promising nano-manufacturing method, as it allows control of alignment direction, is inexpensive, non-damaging, scalable and allows organization of fillers by inter-particle motions. This paper describes the design of an automated image capture and magnetic control system to study the alignment of magnetic graphene nanoparticles in an epoxy matrix by applying a low magnetic field (∼100 mT) and by the automatic image capture of magnetization effects through an optical microscope. This system …can continuously observe the alignment process, providing more accurate information about the behavior of the nanoparticle orientation compared to a manual method that only allowed observation of the sample after the experiment had been conducted. A better understanding of nanoparticle alignment could lead to the development of composites with oriented carbon-based nanoparticle structures. Show more

Keywords: Electromagnet system, magnetic alignment, optical microscope, LabVIEW, automation

DOI: 10.3233/JAE-192083

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. S1-S7, 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. Pre-press, no. Pre-press, pp. S1-S8, 2019