International Journal of Applied Electromagnetics and Mechanics - Volume 45, issue 1-4

Authors: An, Lu | Franck, David | Hameyer, Kay

Article Type: Research Article

Abstract: This paper proposes a Sensorless Field Oriented Control for surface mounted permanent magnet synchronous motor combining two approaches for different rotor speed ranges. The active flux observer is applied at low speed and combined with a back-EMF observer at high speed. This combination allows for an improvement of the rotor position estimation for a large speed range and is therefore resulting in a higher stability of the sensorless control scheme when compared to the conventional back …EMF method. The presented approach is discussed based on simulations. Show more

Keywords: Back-EMF, flux observer, permanent magnet synchronous motor, sensorless speed control

DOI: 10.3233/JAE-141915

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 845-850, 2014

Authors: Sato, Morihiko | Oya, Ryusuke | Ishikawa, Takeo

Article Type: Research Article

Abstract: We have developed a high-frequency pulsed power generation system using either ten or twenty MOSFETs in series. The operation principle of the circuit was elucidated, and the experimental results confirmed the operation of the developed circuit. When twenty MOSFETs were used, repetitive operation was achieved at an output voltage of 10 kV and a frequency of 1 kHz. A preliminary experiment on underwater pulsed electrical discharge is performed, and the occurrence of underwater pulsed electric discharge …was confirmed. Show more

Keywords: Pulsed power, MOSFET, underwater electric discharge

DOI: 10.3233/JAE-141916

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 851-857, 2014

Authors: Matsuoka, Akihiro | Sumino, Masayuki | Ueno, Satoshi | Takeda, Tsunehiro

Article Type: Research Article

Abstract: Superconducting technology has been significantly improved since the superconductor Y-Ba-Cu-O was discovered. This technology has been applied to many medical image-processing applications such as magnetoencephalogram (MEG) and magnetic resonance imaging (MRI). Because the superconducting phenomenon occurs at extremely low temperatures, liquid helium or liquid hydrogen is essential to obtain a low-temperature environment. In addition, it is well known that the decompression of the liquid helium creates superfluid helium. This phenomenon improves the …performance of the superconducting devices. For that reason, a vacuum pump, which can be used at a cryostat, is required. In this paper, we propose a motor that has a small size and simple structure for use in the cryostat. The proposed motor consists of an axial self-bearing motor, superconducting magnetic bearings, and permanent-magnet repulsive-type passive magnetic bearings. The design of the motor and control method is introduced. The experimental results show that the proposed motor has a high possibility for high-speed rotation at extremely low temperatures. Show more

Keywords: Rotary machinery, magnetic bearing, superconducting magnetic bearing, vacuum pump

DOI: 10.3233/JAE-141917

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 859-865, 2014

Authors: Hwang, Kyung-Hwan | Kim, Sung-Ryul | Lee, Jae-Hak | Kim, Dae-Young | Lee, Yuk-Hyung | Kim, Churl-Min

Article Type: Research Article

Abstract: Magnetostrictive (MS) materials exhibit a large strain and a high energy-density, because of their large MS coupling coefficient. In particular, an MS actuator that uses Terfenol-D generates great-force and strain. The efficiency of an MS actuator is highly dependent on the pre-stress, magnetic field intensity, magnetic bias and thermal expansion. The specific type or shape of permanent magnet (PM) needed for a given magnetic bias is determined using numerical simulation. According to magnetic field the heat …created by resistance influences the thermal expansion. This paper proposes the optimal exterior PM for achieving a magnetic bias and minimizing the ohmic heat effect with a geometric composite of an electromagnet considered to be a practically precise MS actuator. Show more

Keywords: Magnetostrictive (MS) materials, MS actuator, magnetic bias, ohmic heat

DOI: 10.3233/JAE-141918

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 867-871, 2014

Authors: Nishida, Hitoshi | Shimada, Kunio | Ido, Yasushi

Article Type: Research Article

Abstract: We proposed a microprocessing method using a magnetic compound fluid for the inner surface of a tube made of a material that is difficult to cut, and clarified the processing characteristics and magnetic field distribution of the tool. The tool inserted into the tube comprises a stack of ring-shaped permanent magnets with spacers between them. There is an almost proportional relationship between the amount of material removed and the processing time, and the processed surface acquires …a mirror finish. Moreover, for tools with shorter permanent magnets, the circularity is improved by processing. Show more

Keywords: Magnetic functional fluid, microprocessing, inner tube surface, magnetic field

DOI: 10.3233/JAE-141919

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 873-880, 2014

Authors: Sang, Yuanjun | Li, Xiang | Gan, Yun | Su, Daniel | Luo, Yun

Article Type: Research Article

Abstract: Prosthetic socket is the only channel for load transfer between limb stump and prosthetic limb, so its design is most important in meeting the requirements of comfort and function. In order to improve comfort and functionality of the upper-limb prosthetic socket, this paper presents a novel design concept of the socket in which the areas and working time of compression can be alternated in needs. A physical model of prosthesis socket with four pressure-adjustable chambers driven …by a vacuum pump was designed to form pressure units in the socket to simulate its function in changing compression loads.The effectiveness of the design was proved by experiments. Show more

Keywords: Prosthetic interface, upper limb prosthesis, safety, comfort, functionality

DOI: 10.3233/JAE-141920

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 881-886, 2014

Authors: Zaidi, Houda | Santandrea, Laurent | Krebs, Guillaume | Le Bihan, Yann | Demaldent, Edouard

Article Type: Research Article

Abstract: In this paper an approach is proposed for the taking into account of the displacement of the probe in the finite element simulation of eddy current testing. The proposed approach allows to reduce the difficulties associated to the finite element meshing. The computations are performed using two finite element formulations. Two test ECT problems are proposed. Numerical results are compared with experimental data.

Keywords: Eddy current testing, finite element method, overlapping method, probe displacement

DOI: 10.3233/JAE-141921

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 887-893, 2014

Authors: Ohji, Takahisa | Kato, Fuyuki | Amei, Kenji | Sakui, Masaaki

Article Type: Research Article

Abstract: This paper deals with the comparative numerical study of repulsive forces acting on a rectangular aluminum plate by using two methods of magnetic levitation (maglev) – conventional ac induction type maglev and ac ampere type maglev proposed by the authors. We made up three-dimensional finite element models for these maglev methods and evaluated calculated repulsive forces in each axis of orthogonal coordinates. As a result, we achieved computer-aided visualization of eddy current in a levitated aluminum …plate and magnetic flux around the plate. In addition, we found that the stability in the guidance direction is fully maintained in both methods, and the repelling force of ac ampere type maglev in the conveyance direction decrease compared to that of ac induction type maglev. Show more

Keywords: Magnetic levitation, ac ampere type, ac induction type, eddy current, finite element analysis

DOI: 10.3233/JAE-141922

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 895-901, 2014

Authors: Kai, Yuichiro | Tsuchida, Yuji | Todaka, Takashi | Enokizono, Masato

Article Type: Research Article

Abstract: The magnetic properties of electrical steel sheet deteriorates due to residual stress, which occurs during the manufacturing process. Therefore, it is important to know the relationship between the magnetic property and the residual stress in order to utilize electrical steel sheets effectively. This paper presents the effect of residual stress on the magnetic properties of motor cores in a rotating machine. First, the local residual stress distribution of the motor core is measured using an X-ray …stress measurement system. Next, the magnetic properties of the motor cores for the different residual stress distributions are measured using a single sheet tester. Based on these results, the maximum permeability and magnetic power loss differed depending on the sample, each of which had a different residual stress. In addition, we attempt to measure the inductance of the motor core in order to easily evaluate the magnetic property. The difference in the inductance of each sample was obtained based on the excitation voltage and frequency measured using an LCR meter. It is very useful to evaluate the inductance in order to easily determinine the difference in the residual stress. Show more

Keywords: Residual stress, motor core, magnetic property, inductance, magnetic power loss

DOI: 10.3233/JAE-141923

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 903-908, 2014

Authors: Kono, Yoshinori | Yoshimoto, Takamichi | Hirata, Katsuhiro

Article Type: Research Article

Abstract: Haptic devices using asymmetric drive have been attracting attention. We have been studying 2-DOF haptic devices using a 2-DOF oscillatory actuator that can independently output asymmetric acceleration waveforms in 2 axes. This paper presents a new 2-Degree-of-freedom (DOF) linear oscillatory actuator. First, its static characteristics are computed by 3-D finite element method (FEM). Then, the dynamic characteristics of the actuator under asymmetric acceleration drive are clarified through FEM analysis and finally compared …with measurements on a prototype. Show more

Keywords: Electromagnetic analysis, finite element method, oscillatory actuator, haptic device, multi-DOF actuator

DOI: 10.3233/JAE-141924

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 909-916, 2014