International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 1-2

Article Type: Editorial

Abstract: Preface to Selected Papers from the 14th International Symposium on Applied Electromagnetics and Mechanics (ISEM 2009), Part I

DOI: 10.3233/JAE-2010-1091

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 1-1, 2010

Authors: Tang, Renyuan | Han, Xueyan | Zhou, Ting

Article Type: Research Article

Abstract: The status of research and analyses of multiple coupling fields of rare earth permanent magnet electrical machines in China is introduced. Permanent magnet electrical machines with novel structure, Permanent Magnet Wind Power Generators, Permanent Magnet AC Servo Motors and Premium- efficiency Line-Start PMSMs are reported respectively.

DOI: 10.3233/JAE-2010-1092

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 3-23, 2010

Authors: Enokizono, Masato

Article Type: Research Article

Abstract: The national project of the development technology of next generation applied electromagnetic machinery was founded in Oita as Oita Prefecture Innovative JST (Japan Science and Technology Agency) Research Program. In this paper, outline of this project is introduced and the basic technology which is based on vector magnetic property is described. Especially the vector magnetic properties in high flux density level of 1.9 T are shown. As the example results, the dynamic vector magnetic characteristic is …applied to the surface permanent magnet motor. Show more

Keywords: Magnetic characteristic analysis, integration-type dynamic E&S modeling, magnetic power loss, high density machines, high efficiency, magnetic material

DOI: 10.3233/JAE-2010-1093

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 25-37, 2010

Authors: Zhang, Yongjie | Sun, Qin

Article Type: Research Article

Abstract: Perfectly matched layers (PML) are the layers of electromagnetic wave absorbing elements designed for the mesh truncation of an open domain in a harmonic or modal analysis. It is an artificial anisotropic material that is transparent and heavily lossy to incoming electromagnetic waves. Conformal PML (CPML) is a convex and smooth shell region made up of lossy anisotropic medium. Generally, a conformal PML region is backed by a PEC boundary condition or a PMC boundary condition. …But there are some reflections back into the computational domain by the PEC (PMC) boundary condition. In order to reduce the reflections, the traditional PEC (PMC) boundary condition is changed into vector absorbing boundary condition (ABC), and functional formula of conformal PML backed by vector ABC is deduced in this paper. Numerical experiments show that conformal PML backed by vector ABC is high-precision and high-efficiency. Show more

Keywords: Conformal PML, vector absorbing boundary condition, electromagnetic scattering

DOI: 10.3233/JAE-2010-1094

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 39-45, 2010

Authors: Lee, Do-Young | Nam, Yun-Joo | Park, Myeong-Kwan | Yamane, Ryuichiro

Article Type: Research Article

Abstract: This paper is concerned with the transparency improvement of a 1-DOF (degree-of-freedom) hybrid haptic device with the wide-ranged haptic reflection. The hybrid haptic device is actuated by the combination of an active actuator and a passive one. A noble hybrid concept for the haptic device is proposed for two purposes; one is to improve the transparency of the haptic device by compensating friction components qualitatively and quantitatively, and the other is to reflect the wide-ranged force …or torque in large workspace. In the proposed hybrid actuation, the passive actuator is used as the main source of the reflective output, since it has the passivity property in nature so that the safety in interaction and the stability in haptic control can be concurrently guaranteed. The active actuator, which is active in nature, is used either for compensating back-driven components in the haptic system or for providing additional outputs in the haptic reflection larger than the maximum capacity of the passive actuator. Show more

Keywords: Haptic reflection, hybrid haptic device, magnetorheological (MR) brake, transparency

DOI: 10.3233/JAE-2010-1095

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 47-53, 2010

Authors: Qin, Penggao | Chen, Zhihua | Sun, Xiaohui | Li, Baoming

Article Type: Research Article

Abstract: Local MHD hypersonic flow control of a scramjet inlet has been conducted in this paper. Two dimensional Euler equations with MHD terms are used for describing the flow filed variations during the control process. An explicit second order Godunov-type scheme is employed to solve the equation, the immersed boundary condition and a block-structured adaptive mesh refinement technique are adopted to handle the complex boundary and high pressure gradient, respectively. Our numerical results show that the MHD …control can be used to restore the oblique shock waves at off-design conditions with the force applied at the forebody of the first ramp in proper directions. Show more

Keywords: MHD, hypersonic flow, flow control

DOI: 10.3233/JAE-2010-1096

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 55-61, 2010

Authors: Sudo, Seiichi | Wakuda, Hirofumi | Asano, Daisaku

Article Type: Research Article

Abstract: The purpose of the present paper is to develop the generator of the capillary magnetic fluid jet. The experiments on magnetic fluid sloshing were conducted at first. Based on the results of experimental study on the fluid motions in a longitudinally vibrated tank with a permanent magnet, a magnetic fluid jet generator was developed. The generator is composed of NdFeB magnets, magnetic fluid, small circular cylindrical tank, and a coil. It is found experimentally that the …magnetic fluid droplets and capillary jet are formed by the generator. Show more

Keywords: Magnetic fluids, capillary jet, droplets, jet generator

DOI: 10.3233/JAE-2010-1097

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 63-69, 2010

Authors: Xiu, Shichao | Tan, Qingchang

Article Type: Research Article

Abstract: According to the static magnetics viewpoint, the no-friction passive magnetic bearings are not stable in their non-load direction. So its position must be limited by certain means for its applications in engineering. Based on the theory of equivalent magnetic charges, the mathematical models for the axial displacement and force of radial passive magnetic bearings were established without any hypothesis and simplifications. In addition, the numerical simulations and the experiments for the axial and radial forces of …radial passive magnetic bearing were performed. It shows that the simulations results tally with the experimental results primarily, and the relative axial displacement between the inner ring and the outer ring of the magnetic bearing not only weakens the radial bearing load capacity regularly, but also induces the axial force and makes the bearings unbalance in axial direction. The researches provide an effective approach to study the performance, the load capacity and the structure of the no-friction passive magnetic bearings. Show more

Keywords: No-friction, passive magnetic bearings, unbalance, model and simulation

DOI: 10.3233/JAE-2010-1098

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 71-77, 2010

Authors: Nakazaki, Osamu | Kai, Yuichiro | Todaka, Takashi | Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents measured iron loss properties of a rotating machine's stator core at each manufacturing stage. It is well known that the magnetic properties deteriorate in constructed cores due to stress in manufacturing process and the iron loss increases in comparison with one of the ideal material used in designing, and then the building factor becomes more than one. In this paper, knowledge obtained in development of a simplified evaluation method of iron losses in …actual stator cores of rotating machines is presented. Show more

Keywords: Electrical steel sheet, iron loss, manufacturing process, rotating machines

DOI: 10.3233/JAE-2010-1099

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 79-86, 2010

Authors: Zhu, Zhi-Wen | Liu, Yue | Xu, Jia | Wang, Hong-Li

Article Type: Research Article

Abstract: In this paper, a kind of giant magnetostrictive actuator (GMA) model based on hysteretic nonlinear theory was developed. Nonlinear difference item was introduced to interpret the hysteresis phenomenon of GMA. The coupling relationship between magnetic field intensity and frequency was obtained in stepwise multiple regression method to describe the driftage of strain curve. Based on above, the final relationship among strain, magnetic field intensity and frequency was set up. The result of significance test shows …that the effects of all of the items in the final model are remarkable, which means that the model can describe the characteristics of GMA in different frequencies well. The new GMA model broadens the region of controlling frequency, and is easy to be analyzed in theory, which is helpful to vibration control. Show more

DOI: 10.3233/JAE-2010-1100

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 87-93, 2010

Authors: Mazauric, Vincent | Drouineau, Mathilde | Rondot, Loïc

Article Type: Research Article

Abstract: A new approach to face the problem of dynamic hysteresis and assess extra-losses in soft magnetic materials is investigated. Thanks to a spatial averaging technique and a variational principle, a dedicated formulation is derived. It takes into account microscopic magnetization mechanisms and domain wall motion-induced Joule losses. A validation is proposed by assessing time-harmonic losses on a 2D-Pry and Bean iron sheet. Discussion includes also a confrontation with the delayed diffusion model and Bertotti's …experiments. Show more

Keywords: Electromagnetism, magnetic materials, transient formulations, eddy currents, dynamic hysteresis, anomalous losses

DOI: 10.3233/JAE-2010-1101

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 95-101, 2010

Authors: Yamaguchi, K. | Suzuki, K. | Nittono, O. | Takagi, T.

Article Type: Research Article

Abstract: Domain wall displacements were simulated using Monte Carlo method with a conventional crystal anisotropy for cylindrical and spherical micro magnetic clusters having a bcc crystal structure. The anisotropy properties of magnetization processes show qualitatively good correspondences with the experimental results for bcc iron. The simulations also demonstrate behaviors of their domain wall displacements and rotation magnetizations on the magnetization processes. Moreover the simulation was applied for a deformed cylindrical cluster elongated 1.01 …times along the [010] direction and the result shows the domain wall displacement has a two steps process. Show more

Keywords: Magnetic anisotropy, magnetic domains, magnetic hysteresis, Monte Carlo methods

DOI: 10.3233/JAE-2010-1102

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 103-110, 2010

Authors: Wang, Jiang-Bo | LI, Yao-Hua | Yan, Lu-Guang

Article Type: Research Article

Abstract: Eddy current braking systems are used in order to avoid the limit of mechanical brake. The eddy current braking system with dc-excited magnet needs the power supply and has the consequent power losses. The braking system using permanent magnets can obtain high efficiency due to no power losses. The magnetic flux density of permanent magnet Halbach array is stronger than that of conventional permanent magnet array. Further more Halbach array is of one-sided flux structure and …has self-shielding property, magnetic field of one side is enhanced and the other side is weakened. Hence applying linear Halbach array to eddy current brake system is studied. Analytical method is used to analyze the electromagnetic mechanism in eddy current brake and the braking force equation is deduced. An experimental system is designed, the braking force equation is verified with the experimental result, and the result of experiment is analyzed. Show more

Keywords: Linear Halbach array, eddy current brake, braking force

DOI: 10.3233/JAE-2010-1103

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 111-118, 2010

Authors: Machado, José Márcio | Shiyou, Yang

Article Type: Research Article

Abstract: This work presents simulations of the Electrofluid Dynamic energy conversion process in slender channel devices having very small particles (in both micro and nano scales) as charge carriers. Solutions are discussed for a system composed by coupled differential equations, which includes the equation for the total current along the channel, the equations for total energy and momentum of the mixture (gas and solid particles), the continuity equation and the equations for energy and momentum of a …single particle. Results for suspended particles of higher diameters have been previously published in the Literature, but the simulations here presented exhibit an appreciable increase in the values for output currents. Show more

Keywords: EFD energy conversion, particulate systems, nanoparticles

DOI: 10.3233/JAE-2010-1104

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 119-125, 2010

Authors: Deng, Xianming | Wang, Lei | Zhang, Jiamin | Wang, Kang

Article Type: Research Article

Abstract: In order to solve problems of complicated structure and huge volume of synchronous machine (SM), this paper presents a brushless synchronous machine with the structure of single stator core and single rotor core. Power windings and excitation windings of stator are laid in the same stator core. Correspondingly, DC excitation windings and AC windings of rotor are laid in the same rotor core, fixed in the machine's rotor by the rotating rectifier which is formed of …commutation diodes. Magnetic field of the new structure machine is analyzed and calculated by ANSYS. The results show that the designed brushless synchronous machine has characteristics such as simple structure and superior performance. Therefore, it has a good application prospect. Show more

Keywords: Brushless synchronous machine, magnetic field analysis, working principle, brushless excitation system

DOI: 10.3233/JAE-2010-1105

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 127-133, 2010

Authors: Hasegawa, Hitoshi | Kashiwagi, Takayuki | Sakamoto, Yasuaki | Sasakawa, Takashi

Article Type: Research Article

Abstract: This paper describes the realization of the magnet rotor type non-contact transformer that is possible to transmit electric power and a torque by non-contact. As for the large air gap as well, this device can transmit electric power and a torque efficiently which compensates for exciting current in the transformer by the permanent magnet flux.

Keywords: Non-contact power supply, Permanent magnet, flywheel

DOI: 10.3233/JAE-2010-1106

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 135-144, 2010

Authors: Dun, Yueqin | Tang, Zhanghong | Zhang, Fang | Zou, Jun | Yuan, Jiansheng

Article Type: Research Article

Abstract: To simplify the calculation of the logging response, a fast approach for simulating the cylindrical electrode only with a point source is presented in this paper. This approach transforms the problem with hollow cylindrical electrodes to that with point sources, which does not only simplify the calculation, but also makes the numerical mode-matching (NMM) method can be employed directly in the calculation. The NMM method is an efficient half-numerical and half-analytical method. By using the approach …and the NMM method, a high-efficiency code has been developed and valified. The characteristics between responses and parameters are analyzed, which is crucial to the inversion problem of logging and useful for logging engineers. Show more

DOI: 10.3233/JAE-2010-1107

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 145-151, 2010

Authors: Machado, José Márcio | Shiyou, Yang | Abe, Nancy Mieko | Passaro, Angelo

Article Type: Research Article

Abstract: This work describes an optical device for the simultaneous recording of shadowgrams and schlieren images, and some results are presented concerning its applications to the study of plasma assisted flow control in airfoil models. This approach offers many advantages in comparison to other methods, specially because the use of tracer particles (like smoke in wind tunnels) is not required for the experiments, thus avoiding contaminations in the electric discharges or air flows. Besides, while schlieren images …reveal the refractive index gradients in the area of study, shadowgrams detect the second order spatial derivatives of the refractive indexes. Therefore, the simultaneous recording of these different images may give interesting information about the phenomena under study. In this paper, these images were used to confirm the existence of vortex structures in the flow induced by corona discharges on airfoil models. These structures are a possible explanation for the effects of drag reduction and lift force increasing, which have been reported in experiments of plasma assisted Aerodynamics. Show more

Keywords: Plasma assisted aerodynamics, corona discharges, air flow control

DOI: 10.3233/JAE-2010-1108

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 153-158, 2010

Authors: Dong, Longlei | Yan, Guirong | Du, Yanting

Article Type: Research Article

Abstract: A novel magnetorheological (MR) damper is presented in this paper. The check valves of the MR damper are configurated in order that the flow direction of the MR fluid is one-way, and the stretch damping force is greater than the compression damping force. The dynamic model of the damper is established, and the theoretical force-displacement diagram is consistent with the test results, which verifies that the dynamic model of the damper is applicable.

Keywords: Magnetorheological damper, structural parameters, theoretical model

DOI: 10.3233/JAE-2010-1109

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 159-165, 2010

Authors: Cundeva-Blajer, Marija | Arsov, Ljupco

Article Type: Research Article

Abstract: In the paper a thorough electromagnetic transient analysis of a combined instrument transformer will be given. A CAD procedure for transformer optimal design by using a genetic algorithm original program will be accomplished. The transient analysis will be fulfilled for the initial and optimal design as well as for a realised transformer prototype. The transient analysis will be non-linear, since the results from previous FEM-3D electromagnetic field study as well as the non-linearity of the two …transformer measurement cores will be incorporated. Show more

Keywords: Instrument transformer, finite element method, genetic algorithm

DOI: 10.3233/JAE-2010-1110

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 167-173, 2010

Authors: Xue, Xiaomin | Sun, Qing | Zhang, Ling | Wu, Xiaohong | Zhang, Lei

Article Type: Research Article

Abstract: Experimental study of the MR damper which is designed and made in our laboratory is introduced in this paper. The experimental results indicate that the mechanical behaviour of the MR damper displays remarkably nonlinear hysteretic characteristics. In order to characterize this nonlinear system, the present study sets out to propose a simplified Bouc-Wen model and then adopt genetic algorithm to identify its parameters. The experimental data of the MR damper responses verify that the proposed approaches …are capable of efficient computations and accurate parameter estimation. Also suggested are the implications of the present study on other novel smart dampers. Show more

Keywords: MR damper, Bouc-Wen model, parameter identification, sensitivity analysis, genetic algorithm

DOI: 10.3233/JAE-2010-1111

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 175-181, 2010

Authors: Woo, Kyungil | Park, Hanseok | Cho, Yunhyun | Kim, Byungtaek | Kim, Daekyong

Article Type: Research Article

Abstract: This paper focuses on the improvement of the torque characteristics of the outer rotor direct drive permanent magnet wind generator that is a radial flux machine with output power of low speed and high torque, 3[kW] 90[rpm] by FEM and optimization. The optimization technique is used to find out a design solution through the comparison of cogging torques according to the shape variation such as the open slot width and the pole arc ratio. In this …technique the problem is to minimize the objective function. The automatic process that includes the automatic ACAD file drawing and mesh generation with regard to the shape variation is also used. The revised generator is obtained from a preliminary model. The cogging torque characteristics of the revised model and the preliminary model and the dynamic characteristics are analyzed. From the simulation results, it is shown that the cogging torque characteristic of the revised model is better than that of the preliminary one. The prototype was manufactured and the simulation result such as induced voltage is agrees with that of the experimental one. Show more

Keywords: Cogging torque, FEM, objective function, optimization, permanent magnet wind generator

DOI: 10.3233/JAE-2010-1112

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 183-190, 2010

Authors: Wang, Jianmin | Jing, Chongyou | Fan, Yana | Liu, Lanrong | Du, Yong | Zhang, Junjie | Jiao, Cuiping | Cheng, Zhiguang

Article Type: Research Article

Abstract: The simplified 3D FEM model coupling with the equivalent electric-circuit (EEC) is well established for a phase-shifting rectifier transformer (PSRT). The 3D stray fields, the parallel branch currents and the short-circuit impedances are calculated by the field-circuit coupling method (FCCM). The validity of the proposed analysis method is verified based on real product, which proved to be more efficient for the design of the PSRT.

Keywords: PSRT, stray fields, short-circuit impedance, FCCM

DOI: 10.3233/JAE-2010-1113

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 191-196, 2010

Authors: Woo, Kyungil | Rhyu, Sehyun

Article Type: Research Article

Abstract: This paper studies on the fault analysis of 3-phase cage induction motor with the mixed fault of the static eccentricity and the broken rotor bars at steady state. A mathematical fault model is presented by the coupled magnetic circuit approach. The calculation of winding inductances is derived by means of a winding function theory. The stator current and the torque are obtained by means of the coupled magnetic circuit method and Park's transformation. The characteristics of …single fault and mixed fault are analyzed. From the simulation results it is shown that there is its own peculiar frequency component obtained by the spectrum analysis of the stator current in the case of a single fault. But in the case of mixed fault, there is a mutual effect between two faults. From the comparison with FEM results, it is shown that the proposed approach can be simulated to diagnose faults in 3-phase cage induction motor. Show more

Keywords: Broken rotor bars, coupled magnetic circuit, static eccentricity, winding function theory

DOI: 10.3233/JAE-2010-1114

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 197-205, 2010

Authors: Yang, Baokun | Luo, Jinglin | Dong, Longlei

Article Type: Research Article

Abstract: This paper presents an optimized design of a magneto-rheological damper with finite element analysis. The MR damper is a new type one compared with the traditional type, which is called the parallel disks valve mode. The effects of magnetic field formation mechanism and MR effect formation mechanism on the MR parallel disks valve performance are investigated. Analytical results of the optimized design of the MR damper with different structural parameters and different materials indicated that the …simulation values by the finite element method are very close to the measured values and also verifies the reliability of the simulation. Show more

Keywords: Magneto rheological damper, magnetic circuit design, fem, optimum design

DOI: 10.3233/JAE-2010-1115

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 207-216, 2010

Authors: Tanaka, Roberto Yuji | Passaro, Angelo | Abe, Nancy Mieko | Vieira, Gustavo Soares | Stephany, Stephan

Article Type: Research Article

Abstract: Self-consistent calculations of multi-quantum well semiconductor structures based on a Finite-Element Method are presented. The self-consistent calculation is specially needed when wells of different width are present in the structure, generating a larger charge separation and affecting significantly the tunneling conditions. The object-oriented computer code used was implemented using a finite-element class library developed and used in previous works. Results for an asymmetric heterostructure with a larger well and contact layers are …also presented. Show more

Keywords: Quantum well, finite element methods, nanotechnology, self-consistency

DOI: 10.3233/JAE-2010-1116

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 217-223, 2010

Authors: Zhang, Guogang | Chen, Wei | Ke, Chunjun | Zheng, Peng | Geng, Yingsan

Article Type: Research Article

Abstract: Dynamic characteristics reflect the real situation of an AC contactor and are very important to the optimum design of AC contactors. A simulation model of intelligent AC contactor has been established using the ADAMS software with developing a user subroutine in which the iterated Runge-Kutta method is adopt to solve a set of differential equations that describe the coupling of circuit, electromagnetic and mechanical systems. Because of reusing the analysis results obtained from the simulation of …static characteristics accomplished by the ANSYS software, the simulation model runs more efficiently. In addition, by using the ADAMS/solver in the batch mode, an optimization library have been integrated with the ADAMS software and successfully used to seek the optimal control parameters to minimize the contact bounces and core bounces. The simulation results show that the intelligent AC contactor with PWM control can effectively reduce the bounces and energy consumption. Show more

Keywords: AC contactor, dynamic characteristics, simulation and optimization

DOI: 10.3233/JAE-2010-1117

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 225-233, 2010

Authors: Jang, Jin-Soek | Kim, Ho-Hyun | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper proposes a method to reduce the torque ripple of a square wave voltage-driven BLDC motor. First of all, this paper reviews a previous voltage control method to reduce torque ripple, and shows that cogging torque component still remains. Then this paper proposes an improved voltage control method to offset cogging torque. To verify the proposed method, FE-analysis is performed for a test BLDC motor and it is shown that torque ripple is considerably reduced …comparing with a previous control. Show more

Keywords: BLDC motor, cogging torque, commutation, torque ripple, voltage control method

DOI: 10.3233/JAE-2010-1118

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 235-241, 2010

Authors: Cao, Ronggang | Fang, Zhang | Zou, Jun | Yuan, Jiansheng

Article Type: Research Article

Abstract: Electromagnetic forces of ferromagnetic materials consist of attractive and repulsive components, which can be introduced from the Lorentz force formula and the Kelvin force formula. In harmonic fields, the attractive and the repulsive forces both have DC and AC components and they cancel out with each other to reduce the total average force. The contributions or influences of the frequency, magnetic permeability and electric conductivity of the material to attractive and repulsive forces in time-varying fields …are analyzed and simulated by the numerical experiments using FEM methods. Results show that the total time average electromagnetic forces can be reduced greatly, even to zero in certain states, which is useful to control the vibration problem. Show more

Keywords: Electromagnetic forces, ferromagnetic materials, time-varying electromagnetic fields

DOI: 10.3233/JAE-2010-1119

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 243-249, 2010

Authors: Choi, Myoung-Hyun | Song, Jeong-Hyun | Woo, Kyungil | Kim, Byung-Taek

Article Type: Research Article

Abstract: In this paper a design condition for magnetically balanced operation in a single phase induction motor is presented in analytic forms. In addition a condition for minimal stator copper is deduced under condition that the balanced operation is satisfied. Using these conditions, an optimal induction motor is designed by a proper optimization algorithm, and its loss characteristics are investigated. From the results, the validity of the proposed method is verified.

Keywords: Balanced operation, minimal stator copper, optimization algorithm

DOI: 10.3233/JAE-2010-1120

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 251-258, 2010

Authors: Liu, Dong-Yao | Zhou, Yan-Huang

Article Type: Research Article

Abstract: The 2-dimensional unsteady expansion process of plasma jet ablated in capillary because of the discharging of pulse power is simulated with CE/SE (conservation element / solution element) scheme in this paper. The high resolution computational space-time CE/SE scheme is simplified and improved to solve the axisymmetric two dimensional Euler equations of the unsteady expansion process of ablation plasma jet in open air. The variation and distribution of pressure and velocity of ablation plasma jet in flow …field are illustrated and analysed. The shock wave and discontinuity of the jet are clearly depicted according to results of simulation, and simulating results are well agreement with experiment. Show more

Keywords: Plasma jet, simulation, CE/SE scheme

DOI: 10.3233/JAE-2010-1121

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 259-269, 2010

Authors: Ciric, Ioan R. | Hantila, Florea I. | Moraru, Augustin | Maricaru, Mihai

Article Type: Research Article

Abstract: By performing holes in a thin electromagnetic shield, its weight and price can be reduced, without practically changing the shielding efficiency for certain geometries and frequencies. A new method for solving the integral equation of the surface current density in thin shields with holes is applied, where the current density is represented by a linear combination of specialized surface vector functions associated with the interior nodes of the discretization mesh and with the sets of nodes …on each hole contour. A Galerkin technique is applied to determine the scalar coefficients of these functions. The magnetic flux density in the shielding zone is obtained accurately, in terms of exact analytical formulas, from these vector functions. Show more

Keywords: Shielding efficiency, current sheet integral equations, thin shields with holes

DOI: 10.3233/JAE-2010-1122

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 271-278, 2010

Authors: Zhao, Yanzhen | Chen, Feng | Kang, Bo | Ma, Xikui

Article Type: Research Article

Abstract: In this paper, the optimum design of round-wire dry-type air-core reactor is considered. An optimum design model is built based on the balance of three additional constraints, which is consist of layer resistance drop equalization, package temperature rise equalization and package height equalization. It is proved that the three additional constraints can not be simultaneously satisfied for a round-wire reactor when the number of packages is greater than 1. For this reason, the additional constraints balance …is proposed for the optimum design of a reactor. According to the optimum design model, a new hybrid genetic algorithm combined with simplex method is introduced and studied in detail. The hybrid genetic algorithm can enhance the local searching ability and improve the optimization efficiency. Finally, the proposed method is applied to the optimum design of dry-type air-core reactor, and a satisfied result is obtained. Show more

Keywords: Optimum design, dry-type air-core reactor, additional constraints, hybrid genetic algorithm

DOI: 10.3233/JAE-2010-1123

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 279-284, 2010

Authors: Yu, Byoung-Hun | Lee, Won-Yong | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper deals with starting characteristics of a single-phase line start permanent magnet (LSPM) motor considering nonlinear properties of magnetic materials. To take into account nonlinearity of iron core according to operating states, d-and q-axis inductances are calculated by magneto-static FE-analysis for various currents. The calculated dq-axis inductances are used in the equivalent circuit of a single-phase LSPM motor and dynamic performances are analyzed with 4th order Rung-Kutta method. The results are …compared with time-step FE-analysis results and the effects of nonlinearity are discussed. Show more

Keywords: Finite element method, line-start, nonlinear, permanent magnet, starting characteristic

DOI: 10.3233/JAE-2010-1124

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 285-292, 2010

Authors: Yan, Rongge | Yang, Qingxin | Yang, Wenrong | Hou, Shuping | Liu, Fugui | Yan, Weili

Article Type: Research Article

Abstract: This paper studies the dynamic response performance of giant magnetostrictive acceleration sensors. A magneto-mechanical strongly coupled dynamic model is presented, which is calculated by means of the finite element method. According to the proposed model, the time characteristic of the induced voltage for the acceleration sensor built with rare earth giant magnetostrictive alloy is calculated. A comparison between the calculated results and measured ones has been carried out to examine the validity of the …proposed dynamic model and the FE implementation. It is found that they are in an agreement. This indicates that the proposed FE model can reflect dynamic response performance of giant magnetostrictive acceleration sensors. Show more

Keywords: Giant magnetostrictive acceleration sensors, dynamic model, finite element method

DOI: 10.3233/JAE-2010-1125

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 293-298, 2010

Authors: Park, Seong-Cheol | Kim, Dae-Kyong | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper deals with design and characteristic analysis of a pole changing written-pole motor (WPM), which is a synchronous motor with self-starting ability. The winding configuration is deliberately determined to get a pole-changing function, and it is confirmed by FEA with time step method. In addition during operation of the exciter, the characteristics of magnetization of magnet and synchronization of a rotor are also analyzed.

Keywords: Pole-changing, self-start, synchronous motor, written-pole motor

DOI: 10.3233/JAE-2010-1126

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 299-306, 2010

Authors: Zhang, Fang | Tang, Zhanghong | Dun, Yueqin | Yuan, Jiansheng

Article Type: Research Article

Abstract: An approach for solving the electrostatic field in 3-D unbounded domains is introduced in this paper, which is the combination of the finite element method (FEM) and the Kelvin transformation. The principle of this method is dividing the whole infinite region into two parts by a spherical surface. In the inner part with a sphere as the boundary, the ordinary finite element method is employed. As for the outer open-boundary part, the approach first transforms it …into a finite closed domain that is of the sphere as the boundary, in which the transmuted FEM is used. It is allowed that the exterior open-boundary part is of non-uniform medium, such as unlimited domains or different shapes with different materials whose interfaces might extend to infinity. Show more

Keywords: Electrostatic field, FEM, grounding, Kelvin transformation

DOI: 10.3233/JAE-2010-1127

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 307-312, 2010

Authors: Seo, Jang-Ho | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: In this paper, we present a magneto-thermal model of an interior-permanent magnet synchronous machine (IPMSM) for electrical vehicle. Both magnetic and thermal field aspects are described based on 2-D finite element method (FEM). For accurate estimation of heat sources in the machine, we analyzed harmonic iron loss using variable loss coefficients and magnet loss in the electromagnetic field. In addition, we estimated convective exchange coefficient considering water-cooling system of the machine. Finally, …experimental results on 60 kW, 3600 rpm are reported and compared with the simulation results. Show more

Keywords: Electric vehicle, finite element method, iron loss, interior permanent magnet synchronous machine, water-cooling system.

DOI: 10.3233/JAE-2010-1128

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 313-319, 2010

Authors: Wang, Yongqing | Li, Lei | Li, Xiaojia | Wang, Haizhou

Article Type: Research Article

Abstract: In the condition of certain electromagnetic levitation coil and spherical sample, according to the expressions of levitation force and absorbed power in magnetic field, the relationship between levitation force, absorbed power and high frequency power supply frequency is established in this paper. In addition, the effect of the power supply frequency on the levitation force of the coil and the absorbed power of the sample is analyzed, and the general rules of frequency parameter selection are …confirmed. Finally, a guiding role in the frequency selection of high frequency power supply in electromagnetic levitation melting is played. Show more

Keywords: Electromagnetic levitation melting, frequency, levitation force, absorbed power

DOI: 10.3233/JAE-2010-1129

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 321-327, 2010

Authors: Rondot, Loïc | Mazauric, Vincent | Ladas, Dimitrios

Article Type: Research Article

Abstract: In order to improve the finite element modeling of macroscopic eddy currents, a quadratic energy-based error criterion is derived from a thermodynamic description of electromagnetism. While the conservation of the electromagnetic power is assessed locally to highlight the ill-checked elements, the state functions provide the global convergence of the calculation within an adaptative procedure. The criterion is shown: suitable for 2D and 3D, independent of the formulation, supporting the body motion. A validation is …given on a Thomson's effect device. Show more

Keywords: Electromagnetism, eddy currents, error criterion, finite element method

DOI: 10.3233/JAE-2010-1130

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 329-333, 2010

Authors: Sun, Peng | Shao, Shuwen

Article Type: Research Article

Abstract: In this paper a novel coil axial magnetic contact for vacuum interrupters is designed and its magnetic field distribution has been analyzed. This asymmetric contacts structure have a static contact with two coils in series and a moving contact without any coil. The structure of the moving contact is simplified. Its strength will be enhanced, and its weight will be reduced, which is helpful to raise the breaking speed of the vacuum interrupter. Using finite method …the 3-D electrode model has been built and the simulation carried out. With the current value at maximal and zero, the axial magnetic field distribution at static contact surface, at moving surface, and at the middle surface between the static and moving contacts have been calculated. And the phase delay time of the axial magnetic field is considered as well. The simulation results provide that this asymmetric axial magnetic field structure can generate strong and uniform axial magnetic field. The residual magnetic field is small and its phase delay time after the current zero is short. Show more

Keywords: Vacuum interrupter, two segments coil, axial magnetic field contact, 3-D magnetic field, simulation

DOI: 10.3233/JAE-2010-1131

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 335-341, 2010

Authors: Kim, Ki-Chan

Article Type: Research Article

Abstract: In this paper, we propose a simulation algorithm for driving characteristics of interior permanent magnet synchronous motor (IPMSM) for electric vehicle considering nonlinear parameters like d-axis and q-axis inductances as well as core loss. D-axis and q-axis inductances as well as core loss parameter are changed according to both current magnitude and current angle between q-axis and current axis because of nonlinearity of magnetic flux density in stator and rotor core. Therefore, the calculation of d-axis …and q-axis inductances with nonlinearity of magnetic flux density and core loss is performed by using FEM. We can get precise driving performance of traction motor for electric vehicle adopting nonlinear d-axis and q-axis inductance table and core loss table. Show more

Keywords: Electric vehicle, IPMSM, driving characteristics, nonlinear inductance and core loss

DOI: 10.3233/JAE-2010-1132

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 343-350, 2010

Authors: Bai, Baodong | Yu, Qing

Article Type: Research Article

Abstract: The field circuit and movement coupled finite element method for the numerical analysis of 2D electromagnetic fields is proposed in the way of studying the electromagnetic fields of the three-phase flameproof induction motor. Numerical results obtained by means of the software of finite element analysis for a typical flameproof induction motor in different operation states such as no-load, static and transient states with load have confirmed positively the feasibility of the proposed method in solving the …electromagnetic problems. It is the foundation of the flameproof induction motor for optimal design. Show more

Keywords: Field circuit and movement coupled, electromagnetic field, three-phase flameproof induction motor, finite element method

DOI: 10.3233/JAE-2010-1133

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 351-359, 2010

Authors: Ishibashi, Kazuhisa | Andjelic, Zoran | Pusch, David

Article Type: Research Article

Abstract: Nonlinear eddy currents induced in steel plate are formulated by the boundary integral equations. The integral equations for the nonlinear analysis are derived by regarding nonlinear terms as fictitious sources. As the periodic electromagnetic quantities in the steel plate are distorted, these fields are expressed with the help of Fourier series, whose fundamental and harmonic fields are determined by solving the corresponding integral equations with the surface magnetic fields given as the boundary values. The internal …and surface electromagnetic fields are obtained numerically one after the other until convergence. In this iterative solution, Newton-Raphson method has been adopted but it is not applicable if the plate thickness approaches zero. So as to solve the difficulty, we adopt a simple iterative method and have confirmed that the method is effective. Show more

Keywords: Boundary element method, simple iterative solutions, nonlinear eddy current analysis, thin steel plate

DOI: 10.3233/JAE-2010-1134

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 361-367, 2010

Authors: Zou, Jianlong | Chen, Feng | Ma, Xikui

Article Type: Research Article

Abstract: The time-delayed Chua's circuit (TDCC) is an infinite-dimensional electromagnetic system with boundary nonlinearity. An analytic nonlinear model is established for the TDCC. Through simulation, it has been revealed that complex spatiotemporal behaviors characterized by irregular space-time patterns may happen in the TDCC. These complex spatiotemporal behaviors result from the boundary nonlinearity and the space-time coupling. Moreover, it has been found that the initial values during one round-trip delay play an important role in …the evolvements of spatiotemporal behaviors at the different locations of the transmission line. Show more

Keywords: Time-delayed Chua's circuit, spatiotemporal pattern, boundary nonlinearity

DOI: 10.3233/JAE-2010-1135

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 369-376, 2010

Authors: Cheng, Weiying | Komura, Ichiro

Article Type: Research Article

Abstract: A line-current model is proposed to calculate eddy current induced by rectangle coils. Eddy current induced by rectangle coils are analytically calculated using this model, and a coil configuration to induce eddy current deeper into a conductive material is proposed. Optimum excitation frequency is also calculated.

DOI: 10.3233/JAE-2010-1136

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 377-385, 2010

Authors: Ding, Keqin | Xin, Wei

Article Type: Research Article

Abstract: Pulsed eddy current (PEC) detection technology is a new non-destructive testing technology. It can be used to detect the inner corrosion of the low-carbon steel pipeline. The frequency is an important parameter affecting the detection results. In this paper, the influences of frequencies on the detection of inner corrosion are investigated by numerical simulated. By using the method of time-domain difference, the optimization of frequency for detecting the inner corrosion of pipeline is performed. The …research results can provide reference for frequency selection in the practical inspection. Show more

Keywords: PEC, pipeline, corrosion, frequency, simulation

DOI: 10.3233/JAE-2010-1137

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 387-394, 2010

Authors: Eguchi, Keisuke | Todaka, Takashi | Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents results of magnetic characteristic analysis of a magnetic flux concentration type surface magnet motor. Firstly influence of number of the rotor poles on the torque characteristics was examined for fixed stator construction and then some constructions of the permanent magnet array were tested to reduce the cogging torque. Their magnetic flux distributions and torque characteristics were calculated by using the finite element method.

Keywords: CSPMSM, FEM (Finite Element Method), permanent magnet, magnetic arrangement

DOI: 10.3233/JAE-2010-1138

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 395-401, 2010

Authors: Ding, Wen | Liang, Deliang

Article Type: Research Article

Abstract: This paper presents the least square support vector machine (LS-SVM) network as a new tool to develop the model of the switched reluctance machine (SRM) and predict the dynamic performances of SRM system. The basic premise of LS-SVM regression is that it forms a very efficient mapping structure for the nonlinear SRM. By using the measured sample data of SRM, the LS-SVM is designed to learn the nonliear magnetization data with rotor position and phase current …as input, and the corresponding flux linkage and torque as output. It has a good capability of generalization and is computationally efficient. With the developed modeling method, a LS-SVM current-dependent inverse flux linkage model and a LS-SVM torque model are used to simulate the dynamic performances of a 6/4 SRM operating as a starter/generator, and the accuracy of the model is tested via comparison to the measurements of steady state phase current characteristics. Show more

Keywords: Flux linkage, least square support vector machine, modeling, switched reluctance machine, torque

DOI: 10.3233/JAE-2010-1139

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 403-413, 2010

Authors: Ishikawa, Seiji | Todaka, Takashi | Enokizono, Masato | Mauchi, Chikara

Article Type: Research Article

Abstract: This paper presents results of magnetic characteristic analysis of a three-phase generator utilizing grain-oriented silicon steel sheets. In the analysis, the finite element method taking account of the two-dimensional magnetic properties is used to make clear rotational iron loss distributions. In this paper, the knowledge obtained in the numerical simulations by means of the integration-type dynamic E&S modeling is reported. Also, the measurement results of a prototype generator designed with the magnetic …characteristic analysis are shown. Show more

Keywords: Three-phase permanent magnet generator, Grain-oriented silicon steel sheets, Iron loss, Integration-type dynamic E&S modeling, Dual-gap-type generator

DOI: 10.3233/JAE-2010-1140

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 415-422, 2010

Authors: Chen, Feng | Zhao, Yanzhen | Ma, Xikui

Article Type: Research Article

Abstract: Based on the formulae for calculating ac resistance of long solenoid and strip conductor, an improved formula for single-layer air-core solenoid was derived. The proposed formula is more accurate and practical by virtue of the asymptotic matching model and the least squares method. Moreover, finite element simulations are performed to illustrate the accuracy of the proposed formula.

Keywords: Single-layer air-core solenoid, asymptotic matching model, least squares method

DOI: 10.3233/JAE-2010-1141

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 423-430, 2010

Authors: Seo, Jang-Ho | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: In this paper, we investigated the effect of slot-pole combination on rotor loss in interior permanent magnet synchronous machine (IPMSM) with distributed armature windings. In order to study the characteristics of the rotor losses, two machines for high-speed operation such as electric vehicle were designed. One is fractional slot winding and the other is conventional one. Based on 2-D time-stepped finite element method (FEM) we analyzed both iron loss and eddy-current loss in the permanent magnet …of the machines according to their driving conditions. From the analysis results, it was shown that rotor iron loss and eddy-current loss of PM of machine employing fractional slot-winding is definitely large at load condition. Show more

Keywords: Distributed armature winding, electric vehicle, fractional slot per pole, iron loss, interior permanent magnet synchronous machine

DOI: 10.3233/JAE-2010-1142

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 431-438, 2010

Authors: Cheng, Yonghong | Jiang, Lili | Hu, Dike | Xie, Xiaojun | Li, Mang | Luo, Naidong

Article Type: Research Article

Abstract: Dielectric property of materials is one of the most fundamental characters. In recent years, there is an increasing interest in the dielectric properties of composite, which consists of matrix and inclusion materials. The volume ratios, component geometry, distribution types of inclusion determine the performance of composite. In this paper, in order to take the factors mentioned above into account, a cubical model and an ellipsoidal inclusion model which contain variables are selected. This article firstly uses …a complex method to discretize the models, and then optimize the discretizition process. After getting the capacitance of every part with basic formula and integral, an electric network is put forward to substitute the original model. It is used to investigate the dielectric property. The relationships between static effective permittivity and the volume ratio, the shape of the inclusion are analyzed. The results obtained by the proposed method are compared with the results got by Maxwell Garnett, logarithmic, Bruggeman and experiment data. The comparison results show the proposed approach has great advantages and different model has specific scope. Show more

Keywords: Electric network, dielectric property, composite

DOI: 10.3233/JAE-2010-1143

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 439-445, 2010

Authors: Kunihiro, Naoki | Todaka, Takashi | Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents magnetic characteristic analysis of an induction motor model core considering two-dimensional vector magnetic properties. In order to reduce rotational iron losses, which generate in the stator core, we tried to make holes at the tooth base parts. As a result, the rotational flux distribution was effectively controlled by making holes. The results showed that reduction of the total iron loss might be possible by finding out effective holes' size, shape and position.

Keywords: Induction motor, hole, two-dimensional vector magnetic properties, iron loss

DOI: 10.3233/JAE-2010-1144

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 447-456, 2010

Authors: Liu, Yanqin | Wang, Shuhong | Meng, Xiangjun | Qiu, Jie | Feng, Bin | Wei, Caixia | Liu, Fanghua

Article Type: Research Article

Abstract: In this paper, the kinetic characteristics of high voltage power transformer under short-circuit operation are simulated and the influence of prestress is analyzed for the winding stability. Firstly, the finite element method (FEM) is applied to calculate the leakage magnetic field of transformer and electromagnetic force of windings. Secondly, the axial electromagnetic force under short-circuit condition acts on the transformer windings, which are regarded as complex viscoelastic system. The characteristics of the vibration …responses, such as dynamic displacement and dynamic force, are illustrated and their frequency responses are analyzed. Finally, the relationship between prestress and peak value of dynamic force, and as well as displacements of each pancake coil, are discussed. Show more

DOI: 10.3233/JAE-2010-1145

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 457-464, 2010

Authors: Guo, Liuming | Wang, Shuhong | Guo, Ningning | Qiu, Jie | Zhu, Jian Guo | Guo, Youguang | Wang, Yi | Xu, Wei

Article Type: Research Article

Abstract: This paper presents a method based on Current Hoop Model for the analysis and design of induction coilgun. The cylindrically symmetric armature is subdivided into concentric hoops with diverse rectangular cross-sections, in each of which the current is assumed to be uniformly distributed. An equivalent analytical model considering mutual coupling of coils and armature hoops is constructed for dynamic simulation of the coilgun. Based on this model, the self- and mutual-inductances of exciting winding and hoops …are calculated by Neumann method. The circuit equations are solved coupled with the equation of motion of projectile by using the Treanor method to ensure the convergence. Comparison between the experimental results and the numerical results simulated by Finite Element method (FEM) shows the validity of the presented simulation method for coilgun. The optimization of a six-stage coilgun is achieved by employing the genetic algorithm (GA). Show more

Keywords: Electromagnetic coilgun, equivalent analytical model, genetic algorithm

DOI: 10.3233/JAE-2010-1146

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 465-471, 2010

Authors: Wang, Yi | Zhu, Jianguo | Wang, Shuhong | Guo, Youguang | Xu, Wei

Article Type: Research Article

Abstract: In this paper a comprehensive nonlinear model of surface mounted permanent magnet synchronous machine (SPMSM) is proposed considering both the structural and the saturation saliencies to enable the numerical simulation of new rotor position detection algorithms. An experiment platform is carried out to test and collect the incremental inductance values varying again the stator current levels and the rotor position. The Least Relative Residual Sum of Square (LRRSS) method is employed in the nonlinear inductance function …regression. After experimentally identifying out all the parameters, a nonlinear mathematic model of SPMSM is built up. Furthermore, the direct torque control (DTC) scheme is applied to this new model to verify the model and simulate the machine performance. Show more

Keywords: Finite element methods, nonlinear magnetic, PM machines, saturation saliency

DOI: 10.3233/JAE-2010-1147

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 473-479, 2010

Authors: Zeng, Zhiwei | Udpa, Lalita | Udpa, Satish S.

Article Type: Research Article

Abstract: Three-dimensional simulation of eddy current testing (ECT) using finite element method (FEM) has been studied over the past three decades and various methods have been developed. In these methods, the ferrite-core probe is meshed together with the sample. Hence, simulation of probe scanning requires re-meshing, which is not only cumbersome but also a major source of computational noise. In this paper, we propose a novel FEM for the simulation of ECT with ferrite-core probe in which …the meshes of ferrite core and sample are generated separately and the coil is not meshed. The new method avoids re-meshing for different probe positions and is simple, flexible, accurate, and efficient. Show more

Keywords: Eddy current testing, finite element method, ferrite-core probe, reduced magnetic vector potential

DOI: 10.3233/JAE-2010-1148

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 481-486, 2010

Authors: Luo, Ping | Yao, Li-Hai | Yang, Shi-You | Ni, Guang-Zheng

Article Type: Research Article

Abstract: The optimal design of a 300~MJ superconducting magnet using Bi2223/Ag tapes is studied. The multiple solenoid type is used for the HTS magnet in view of reducing the stray field and structural simplicity. The improved particle swarm optimization algorithm is used to optimize the proposed configuration under constraints such as the fixed storage energy, the volume of the superconductor, the stray field and so on. Finally, finite element method (FEM) is used to validate the storage …energy, the magnetic field, the force in a single solenoid and the stress constraint of the optimal structure. Show more

Keywords: HTS tapes, optimal design, multiple solenoid type

DOI: 10.3233/JAE-2010-1149

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 487-493, 2010

Authors: Murakami, Iwanori | Yoshizawa, Akinori | Kobayashi, Yuusuke | Ando, Yoshinori | Yamada, Kou | Nagaya, Kosuke

Article Type: Research Article

Abstract: In this research, we propose the high-TC superconducting levitation synchronous motor that the levitation, the drive, and the vibration suppression are possible with the single disk type rotor composed by some permanent magnets. The center of gravity position is low because this rotor is the single disk structure, and the pitching doesn't occur easily. The displacement of the horizontal direction when the levitation rotor rotates is measured with the laser displacement meter. And, the vibration is …controlled by feeding back this whirling speed to an damper. The High-TC Superconducting Levitation synchronous motor with such a vibration suppression mechanism is developed, and utility is verified by the experiment. Motion analysis and the numerical analysis of the force of an damper were done. Show more

Keywords: Superconductor, levitation, vibration control, synchronous motor, single disc

DOI: 10.3233/JAE-2010-1150

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 495-502, 2010

Authors: Fang, Xu | Qiu, Jie | Xiao, Hongli | Wang, Shuhong | Zhang, Jingyin | Gong, Weizhi | Xin, Ying

Article Type: Research Article

Abstract: In this paper, the transient short-circuit current of three-phase saturated core high temperature superconducting (HTS) fault current limiter (FCL) is investigated by using a method of combining 3-Dimensional (3D) finite element analysis (FEA) and equivalent dynamic nonlinear circuit model. The numerical computations are verified by the experiment results on a FCL prototype with rated voltage 380V. Based on the short-circuit current of three-phase saturated core HTS FCL with rated voltage 220 kV, the three-phase …transient magnetic field is simulated and analyzed. According to the simulation results, the transient short-circuit electromagnetic forces distribution is obtained. Show more

Keywords: Fault current limiter, finite element analysis, transient analysis, electromagnetic force

DOI: 10.3233/JAE-2010-1151

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 503-510, 2010

Authors: Wang, Shuhong | Qiu, Jie | Liu, Xinying | Wang, Zhixuan | Zhu, Jianguo | Guo, Youguang | Lin, Zhi Wei | Wang, Yi | Xu, Wei

Article Type: Research Article

Abstract: This paper presents a hysteresis model for Type-II high temperature superconductor (HTS) by using simplified Preisach Model, in which the Preisach distribution function μ_k α, β) is determined only based on the B-H limiting loop. The nonlinear dynamic circuit model of the superconductor is established. In the circuit model, the hysteresis inductance and hysteresis loss described by using simplified Preisach Model are deduced. Applying the hysteresis circuit model, the currents flowing …in different superconductor layers of high temperature superconducting cable are simulated, as well as the hysteresis loss of the superconducting cable. The simulation results are verified by comparison with the data recorded in literatures. Finally, the influences of hysteresis on superconducting cable are analyzed and discussed. Show more

Keywords: Superconducting cable, hysteresis, Preisach model, current distribution

DOI: 10.3233/JAE-2010-1152

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 511-517, 2010

Authors: Zhao, Xian-Feng | Zhou, You-He

Article Type: Research Article

Abstract: The equilibrium height (EH) of a levitated permanent magnet (PM) is investigated in an oscillation system composed of the PM and a high temperature superconductor (HTS). Two kinds of initial quasi-static magnetization processes are performed respectively, and then the EH is achieved after a damped vibration of the PM. A peak value of the EH, associated with a transitional magnetization height (TMH), is found for the first initial process. When the magnetization height (MH) is less …than the TMH, the EH increases with the increasing of the MH nonlinearly. Otherwise the EH decreases linearly with the MH. For the second initial magnetization process a minimum value of the EH is also presented. The magnetic energy of the system is believed to be responsible for these two different dependences. Show more

Keywords: Equilibrium height, initial magnetization process, Preisach model, current distribution

DOI: 10.3233/JAE-2010-1153

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 519-525, 2010

Authors: Li and, Zhiyong | Wang, Yao | Wang, Wei | Wang, Xuyou

Article Type: Research Article

Abstract: In order to study the interaction between laser and MIG plasma, the radiation of YAG laser-pulsed MIG hybrid plasma is collected with fiber spectrometer. High speed video is also applied to study the coupling effect of laser-MIG hybrid welding plasma. Absorption of laser beam by the plasma is the main reason for the interaction, among which inverse bremsstrahlung process and photoionization are the dominant process. The spatial distribution of spectrum is also acquired to provide experimental …base for interaction analysis. The result shows that there is a high radiation intensity zone with great gradient in the center of laser-MIG hybrid plasma. An `ionized duct zone' is formed near the laser acting point. The above coupling effect provides a satisfied explanation for the better bead formation and more stable arc in the laser-MIG hybrid welding process. Show more

Keywords: Laser, plasma, hybrid welding, spectrum

DOI: 10.3233/JAE-2010-1154

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 527-532, 2010

Authors: Albanese, Raffaele | Artaserse, Giovanni | Bellizio, Teresa | Rubinacci, Guglielmo | Fresa, Raffaele | Viola, Bruno | Palumbo, Maurizio Furno | Villone, Fabio | Liu, Yueqiang | Contributors, JET-EFDA

Article Type: Research Article

Abstract: The impact of the 3D effects on the dynamic response of the plasma in the JET tokamak is assessed on the time scale of interest for plasma magnetic control and stabilization. These effects are due to the limbs of the magnetic circuit and to the eddy currents in the 3D metallic structures. The plasma behaviour is taken into account by a specific matrix of modified inductances interacting with the remaining part of the system via a virtual …coupling surface. Show more

Keywords: Coupled problem, MHD, eddy currents

DOI: 10.3233/JAE-2010-1155

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 533-540, 2010

Authors: Yu, Yonggang | Yan, Shanheng | Zhao, Na | Zhang, Qi

Article Type: Research Article

Abstract: The effects of boundary shape on the propagation form of the plasma jet in liquid media are studied. The construction and consecutive expansion processes of plasma jet in liquid are recorded by high speed digital camera system. The results indicate that the expansion construction of plasma jet in liquid is a typical Taylor cavity, and the axial expansion velocity of Taylor cavity in stepped-wall chamber is greater than that in cylindrical chamber. Based on the experiments, …numerical simulations of the interaction of non-steady plasma jet with liquid media are carried out. The change characteristics of pressure and velocity in plasma jet flow field have been obtained. Show more

Keywords: Plasma jet, taylor cavity, propagation form, numerical simulation

DOI: 10.3233/JAE-2010-1156

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 541-548, 2010

Authors: Zhang, Liang | Han, Zandong | Wang, Bingfang

Article Type: Research Article

Abstract: The fuel balls counter is used to monitor the ball-passing information in the transmission pipeline of high temperature gas-cooled reactor (HTGR). It's the eye of fuel handling system and plays an important role in ensure the reactor's safe work. Regarding the high temperature and radioactive environment in fuel handling system, eddy current testing method is the best choice for fuel balls detection. Because of the magnetic shielding of the thick walled stainless steel pipe, the ball-passing …signal is weak. In order to increase signal to noise ratio and anti-interference ability, the parameter optimization of the sensor is performed by electromagnetic field simulation in this paper. The optimal goal is to maximize the coil impedance changing ratio between conditions of with and without ball inside pipeline. Show more

Keywords: Coil parameters, electromagnetic field simulation, finite element analysis, optimization design

DOI: 10.3233/JAE-2010-1157

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 549-557, 2010

Authors: Tronco, Mário Luiz | Machado, José Márcio

Article Type: Research Article

Abstract: This paper describes an electronic device conceived to convert common web texts into sequences of corresponding Braille signals, which are immediately reproduced onto an array (keyboard) of electromechanical actuators. These actuators are reconfigurable in real time, displaying the Braille characters as matrices of points composed by small stems which can be lowered or raised according to the Braille code. The device, together with its conversion software package, can provide direct access to web texts in any …personal computer, thus avoiding the use of complicated Braille printers. Show more

Keywords: Braille characters, web texts, electromechanical actuators

DOI: 10.3233/JAE-2010-1158

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 559-564, 2010

Authors: Zhang, G.H | Hu, S.Y.

Article Type: Research Article

Abstract: The advantage of geophone with large damping in receiving and compensating high frequency signals is studied theoretically and experimentally. It is found that, as the damping ratio increases, the frequency characteristic of geophone in domain frequency region approximates to the acceleration characteristic gradually, thus the receiving frequency bandwidth of land seismic acquisition is widened and the record of high frequency signals is enhanced. The adopted micro-electronic technology not only increases the geophone …damping largely, but also reduces the output impedance of geophone. The in-situ record data by self-designed geophones with large damping demonstrates higher visual frequency and S/N ratio, and stronger spectrum energy. The proposed method is expected to apply to the moving-coil geophone for high resolution seismic exploration. Show more

Keywords: Damping, moving-coil geophone, frequency characteristic, receiving frequency bandwidth, high resolution seismic exploration

DOI: 10.3233/JAE-2010-1159

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 565-571, 2010

Authors: Perrin, Stéphane | Mawatari, Shingo | Kayata, Ryo | Maki, Koichi | Miya, Kenzo

Article Type: Research Article

Abstract: Electromagnetic (EM) sensors, by directly measuring the impeller of a rotating machine, offer a powerful way to detect not only defects on the impeller itself but to indirectly assess the condition of the bearings too, through the measurement of the displacement of the shaft and of the impeller. In this paper, a new method that uses statistical features computed on the time domain signals of a rotating impeller measured with several EM sensors is proposed. It …is shown that the proposed method allows the full characterization the wear-out (type and quantitative evaluation of the wear-out) in friction bearings. A real world application of this method is presented. Show more

Keywords: Electromagnetic sensor, friction bearing, eddy current

DOI: 10.3233/JAE-2010-1160

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 573-579, 2010

Authors: Song, Xiaochun | Jin, Zhisheng | Yu, Hao

Article Type: Research Article

Abstract: The uniform and steady bias magnetic field is the key to improvement of the transduction efficiency for the magnetostrictive guided-wave transducer. To optimize the magnetic circuit of the magnetostrictive transducer and obtain the best detection effects, the method to measure the homogeneity of magnetic flux density by sample standard deviation was studied. And the effects of such parameters as the thickness of the left and right enclosed magnetic conductor shell, the thickness of the outside round …shell of magnetic conductor, the distance between the bias magnetic exciting coil and the pipe's outer wall on the homogeneity of the excited bias magnetic field were analyzed quantitatively, both finite element simulation and experimental analysis were conducted to study the effects of different magnetic circuit design schemes on the excited bias magnetic field's homogeneity. The simulation results indicate that the homogeneity of the magnetic field is obviously improved with the above three parameters increasing, and the relatively uniform magnetic field can be obtained when the above parameters are all taken the maximum value of 20~mm. Show more

Keywords: Bias magnetic field, homogeneity, standard deviation, magnetostriction, guided wave

DOI: 10.3233/JAE-2010-1161

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 581-588, 2010

Authors: Jin, Sang-Min | Zhu, Yu-Wu | Lee, Sung-Hyung | Cho, Yun-Hyun

Article Type: Research Article

Abstract: sThe problem in improving the high positioning precision of permanent magnet linear synchronous motor (PMLSM) is the large detent force that is caused by the attraction between the permanent magnet (PM) and the iron core without input current. This detent force can be divided into two components: the slot effect and the end effect. In this paper we propose a novel method to reduce the detent force by employing the optimal designed auxiliary poles. To investigate …the characteristics of the detent force of PMLSM with auxiliary poles, the width, position, and height of auxiliary poles are chosen as the optimal factors and the two dimensional (2-D) finite element method (FEM) is used to predict to the values of detent force with different combinations of these three factors. And then the structure of auxiliary poles is optimized by the response surface method (RSM) through the fractional factorial design (FFD). Finally, the effectiveness of our proposed technique is verified by both the numerical calculations and experimental results. Show more

Keywords: Permanent magnet linear synchronous motor, detent force, optimal design, finite element method, response surface method

DOI: 10.3233/JAE-2010-1162

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 589-595, 2010

Authors: Zhang, Zhijun | Xu, Minglong | Feng, Bo | Zhang, Xinong

Article Type: Research Article

Abstract: A new inchworm-type piezoelectric actuator with round trip, variable step, large displacement is presented in this paper. It has two parts: the clamping structure, the pushing structure. Experiment system with high voltage drivers and closed-loop control system is designed. Dynamic model for piezoelectric actuator is built up. This actuator can move a displacement of ± 8 mm. Dynamic performance of the actuator is simulated by the MATLAB Simulink, and the results of simulation is in agreement …with that of the experiment in 30 nanometer accuracy demanded. Show more

Keywords: Inchworm, variable step, closed-loop, simulink

DOI: 10.3233/JAE-2010-1163

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 597-604, 2010

Authors: Zhu, Yu-Wu

Article Type: Research Article

Abstract: This paper proposes a novel technique to reduce the detent force in permanent magnet linear synchronous motor (PMLSM) using auxiliary poles. The detent force that is caused by the attraction between the permanent magnet (PM) and the iron core without input current can be divided into two components: the slot effect and the end effect. To reduce these two effects, we analyze the characteristics of the detent force according to semi-closed slot clearance length and auxiliary …poles position by using the two-dimensional (2-D) finite element method (FEM). The numerical calculations and the experimental results prove that this proposed technique has a good effect on the reduction of the detent force. Show more

Keywords: Permanent magnet linear synchronous motor, detent force, auxiliary poles, end effect

DOI: 10.3233/JAE-2010-1164

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 605-611, 2010

Authors: Wang, Haitao | Luo, Qiufeng | Cai, Jiahui | Zhang, Yajing | Wan, Junwei | Zhu, Yongkai | Tian, Gui Yun

Article Type: Research Article

Abstract: The principle of the inductance displacement sensor on optical aperture synthesis telescope is given with a measurement of mutual inductance to deduce the axial distance. It illustrates an effective modelling and calculation method based on Partial Element Equivalent Circuit (PEEC). PEEC is the method to calculate mutual inductances between coils utilizing partial parameter concept. Simulation for the change of mutual inductances is done which is prepared for the next step work.

Keywords: Optical aperture synthesis, mutual inductance, displacement sensor

DOI: 10.3233/JAE-2010-1165

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 613-620, 2010

Authors: Li, Jian | Cho, Yunhyun

Article Type: Research Article

Abstract: This paper presents the study of a high performance 3-Phase 3.7kW 2-Pole line start permanent magnet synchronous motor for pumping system. A method was proposed to study the starting torque characteristics considering line start with high inertia load. A direct-quadrate model including cage was built to study the synchronization capability. Two-dimensional transient finite element analysis was utilized for accurate calculation of efficiency, starting current speed curve and etc. Structural analysis was also conducted to study …the equivalent stress displacement of rotor at rated speed. Show more

Keywords: Line start permanent magnet synchronous motor, cage torque, braking torque, structural analysis, efficiency

DOI: 10.3233/JAE-2010-1166

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 621-628, 2010

Authors: Yuan, Qi | Ishikawa, Takeo | Oono, Masafumi

Article Type: Research Article

Abstract: In this paper, first the structure and composition of a new linear actuator with Soft Magnetic Composite material is presented. Next we study the simulation model of the linear actuator. By pole-placement design, the state-space model with a full-state feedback control is obtained. The result of simulation is given, and compared with the result of experiment. The results show that the two are basically the same.

Keywords: Actuator, analysis, SMC

DOI: 10.3233/JAE-2010-1167

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 629-637, 2010

Authors: Tagawa, Akihiro | Fujiki, Kazunari | Kojima, Fumio

Article Type: Research Article

Abstract: This paper presents development of a defect monitoring sensor using electromagnetic acoustic transducer (EMAT). The present study investigates the possibility of the defect monitoring using a new EMAT structure. The current EMAT was unsuitable for monitoring because of the large sensor area, and also it was necessary to have a mechanical scanning. Therefore, it was developed a new EMAT, smaller in size which does not need a mechanical scanning. The new EMAT was manufactured for a …trial purpose. Based on the result of the performance test, it was found out that the new EMAT is able to monitor a defect and also to monitor both a thin and thick piping wall. Show more

Keywords: Electromagnetic acoustic transducer (EMAT), halbach magnet structure, double coil

DOI: 10.3233/JAE-2010-1168

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 639-647, 2010

Authors: Yang, Byoung-Yull | Hwang, Kyu-Yun | Shin, Dong-Joo | Kwon, Byung-Il

Article Type: Research Article

Abstract: This paper introduces a rotor core in an interior permanent magnet type brushless DC motor. The rotor core consists of a rotor surface having a non-uniform air gap and a novel magnetic flux barrier. We show that, in the rotor core, the rotor surface having the non-uniform air gap effectively reduces the cogging torque while the optimized magnetic flux barrier reduces the cogging torque, and increases the average torque and the efficiency.

Keywords: Cogging torque, IPM type BLDC motor, taguchi method

DOI: 10.3233/JAE-2010-1169

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 649-654, 2010

Authors: Yang, Wenrong | Yang, Qingxin | Yan, Rongge | Liu, Suzhen | Yan, Weili

Article Type: Research Article

Abstract: A kind of magnetic fluid acceleration sensor (MFAS) is presented in the paper, which is using the magnetic and fluid characteristic of magnetic fluid. First, the output characteristics of MFAS and its static sensitivity are analyzed based on minimum potential energy principle, the result indicates the linear relationship between output voltage and acceleration. Then, the experimental research is carried out and compared with piezoelectric acceleration sensor simultaneity based on ZJY-601A experiment platform. The …output signal of MFAS is sampled and processed by the signal processing system, the output waveform demonstrate that the experimental results are both in agreement with theoretical analysis and output of piezoelectric acceleration sensor. Finally, system errors and influencing factors on measurement sensitivity are analyzed qualitative. Show more

Keywords: Magnetic fluid, acceleration sensor, dynamic response, permanent magnet

DOI: 10.3233/JAE-2010-1170

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 655-663, 2010

Authors: Ohno, Takeshi | Takeno, Takanori | Miki, Hiroyuki | Takagi, Toshiyuki

Article Type: Research Article

Abstract: The strain properties of the W-DLC coatings were evaluated. W-DLC coatings with various concentrations were prepared by chemical vapor deposition and DC magnetron co-sputtering of a tungsten metal target. Strain was applied to a sample in a four-point bending configuration. The electrical resistance was proportional to the amount of compression and tensile strain, and the gauge factor varied according to the metal concentration. Transmission electron microscope was employed for structure analyses. It was clarified that the …structure of the W-DLC was granular. The variation of the resistance under the strain could be explained by a simplified model related to the distance between the clusters. The W-DLC coatings have the potential for strain sensor application. Show more

Keywords: Amorphous carbon, strain sensor, smart material

DOI: 10.3233/JAE-2010-1171

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 665-671, 2010

Authors: Hong, Do-Kwan | Woo, Byung-Chul | Choi, Jae-Hak | Koo, Dae-Hyun

Article Type: Research Article

Abstract: Moving Permanent Magnet (PM) type Longitudinal Flux Linear Motors (LFLMs) are electromagnetic devices which can develop directly powerful linear motion. This paper deals with an effective analysis of PM-type LFLM by Finite Element Method (FEM) and optimum design for lightweight. This paper presents the statistical optimum design of PM-type LFLM to reduce the weight of a moving PM-type linear actuator with the constraint of avg. thrust force using the penalty method with characteristics function and kriging …interpolation method. The contribution and effect of the each design variable on the characteristic function is evaluated by the analysis of means (ANOM) and optimum design set is determined. The generalized reduced gradient (GRG) algorithm is adopted in kriging model. Therefore, it is expected that the proposed optimization procedure using penalty method and kriging interpolation method can be easily utilized to solve the optimization problem with constraint of electric machine. Show more

Keywords: Penalty method, characteristic function, kriging interpolation method Analysis of Means (ANOM), statistical optimum design, moving Permanent Magnet (PM) type Longitudinal Flux Linear Motor (LFLM)

DOI: 10.3233/JAE-2010-1172

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 673-680, 2010

Authors: Shang, Xinchun | Qin, Liping | Wang, Fan

Article Type: Research Article

Abstract: The periodic vibration of a magnetostrictive actuator is analyzed. The problem is described in mathematical as solving the displacement response of a Terfenol-D rod excited by the input harmonic alternating current. The governing equation and boundary condition include periodically variable coefficient with time. As the magnetoelastic coefficient of Terfenol-D is small, a regular perturbation approach is employed to approximately solve the analytic solution of the problem. The displacement response curves and amplitude-frequency …characteristic curves from the presented analytic solution agree well with the numeric solution and the experimental data in reference. The study indicates that the double frequency effect generates in the case of no biasing magnetic field. However for high biasing magnetic field, the output displacement depends in synchronous and linearly on the input current. These features of the solution could provide applicable information for control design of magnetostrictive actuators. Show more

Keywords: Magnetostrictive actuator, Terfenol-D, periodic vibration, analytic solution, double frequency effect

DOI: 10.3233/JAE-2010-1173

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 681-688, 2010

Authors: You, Yong-Min | Kim, Dae-Kyong | Kwon, Byung-Il

Article Type: Research Article

Abstract: This paper presents the design of a reliable rotor shape of a BLDC motor used for reciprocating compressor considering demagnetization. Three types of rotor shape are proposed for BLDC motor and a proper rotor shape is selected by characteristic analysis using the 2D finite element method (FEM). To verify the accuracy of the analysis results, a prototype was built and tested. In order to design a reliable rotor shape against the demagnetization of the ferrite magnet, …the demagnetization analysis is performed according to variation of design variables of the ferrite magnet using the 2D FEM. As a result, the BLDC motor with the developed rotor shape showed good performance to resist partial demagnetization. Show more

Keywords: Demagnetization, BLDC, Reciprocating Compressor, ferrite magnet, FEM

DOI: 10.3233/JAE-2010-1174

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 689-695, 2010

Authors: Ishikawa, Takeo | Tsuchitani, Osamu

Article Type: Research Article

Abstract: In this paper, we analyze the steady state characteristics of an experimental capacitor motor by 3-D non-linear FEM coupled with the voltage equation. Next, we propose several methods to improve the motor efficiency by considering the flux density distribution. The motor model where the rotor bars are spread inside can improve the motor efficiency by 4.7%.

Keywords: Capacitor motor, efficiency, finite element method

DOI: 10.3233/JAE-2010-1175

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 697-704, 2010

Authors: Miki, Hiroyuki | Okuyama, Takeshi | Kodaira, Shingo | Luo, Yun | Takagi, Toshiyuki | Yambe, Tomoyuki | Sato, Takeshi

Article Type: Research Article

Abstract: Artificial esophagus of less invasive medical applications utilizing mechanical property of shape memory alloys (SMAs) with peristaltic motion is developed. The artificial-esophagus is composed of two SMA springs, polyvinyl chloride tube, and acrylic plate. The dynamic characteristics of an artificial-esophagus actuator are evaluated in terms of the food transport capacity. Closing pressure and the transport speed have sufficiently realized with human-like qualities. The possibility for fully self-contained artificial-esophagus using SMAs is discussed.

Keywords: Artificial esophagus, peristaltic motion, shape memory alloy, actuator

DOI: 10.3233/JAE-2010-1176

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 705-711, 2010

Authors: Zhang, Xiao-Ju | Chen, Min-You | He, Wei | He, Chuan-Hong

Article Type: Research Article

Abstract: In order to reduce the error in image reconstruction caused by changeable positions of the electrodes in Closed Electrical Impedance Tomography (CEIT), an Open EIT (OEIT) model was proposed using fixed electrode array. The problem is assumed to be a virtual field by defining certain local sensitive area instead of solving the boundary problem in the whole electromagnetic field strictly. Modeling and simulation of OEIT have been conducted to determine reasonable boundary parameters and electrode array …structure. The image was reconstructed by iterative Newton-Raphson algorithm with Tikhonov and Variation regularization. The experiment results showed that OEIT achieved good resolution and positioning accuracy, and can be applied to distinguish small difference in conductivity of the biological tissues. Show more

Keywords: Open electrical impedance tomography, modeling, regularization

DOI: 10.3233/JAE-2010-1177

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 713-720, 2010

Authors: Zhu, Haitao | Demachi, Kazuyuki

Article Type: Research Article

Abstract: Iron concentration is an important parameter for clinical usage of superparamagnetic iron oxide particles. Traditional T_{2} mapping for iron concentration measurement requires several images and long scanning time. This work proposes a method using phase characteristic of magnetic resonance imaging to analyze the magnetic field inhomogeneity caused by superparamagnetic iron oxide particles. Phantom experiments are implemented on 4.7T MRI system. Phase dependence on time of echo and iron concentration is …discussed. Results validate the feasibility of measuring superparamagnetic iron oxide particle concentration by phase data at one single scanning. Show more

Keywords: Magnetic resonance imaging, superparamagnetic iron oxide, phase image

DOI: 10.3233/JAE-2010-1178

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 721-726, 2010

Authors: Li, Ming | He, Wei | Li, Qian | Xu, Zheng | Luo, Cong

Article Type: Research Article

Abstract: A new numerical integral method of the Hankel transform which included the dual Bessel function in the integrand was presented. Because of the strong-oscillation and slow-decay properties of the Bessel functions, it is impossible to use a normal numerical integration method. In our method, the integral interval [0, ∞) is divided into two parts: [0, λ _0 ] and [λ _0 , ∞). In [0, λ _0 ], the integration can be calculated using …a Gauss-Legendre quadrature method between the adjacent zero points. And in [λ _0 , ∞), the Hankel transform is converted to the Fourier cosine or sine transform, and can be calculated with a polygonal approximation algorithm. The proper value of the dividing point of λ _0 was discussed. The simulation results of the test functions show that the algorithm is correct and accurate. Finally, the forward problem of the multi-layer medium magnetic induction tomography was calculated with this new method, and the eddy current distribution in the model and the induced voltages in the detection coils were simulated. Show more

DOI: 10.3233/JAE-2010-1179

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 727-734, 2010

Authors: Čáp, Ivo | Čápová, Klára

Article Type: Research Article

Abstract: The paper deals with an electromechanical model of liquid flow in a tube in order to model blood flow in vessels. The present paper deals with detailed mathematical development of a model based on the theory of electrical long line with distributed elements. The detailed derivation of primary parameters of the analogical electric circuit is described. There are presented some results of application of the model like wave impedance and wave vector of the blood pulse …wave, which are important for the model application to the blood vessels system diagnosis. The significant parameter of the pulse wave – the pulse wave velocity (PWV) has been evaluated and the calculated values of phase and group velocities in selected vessels have been confronted with physiological data. Show more

Keywords: Electromechanical analogy, electromechanical models, blood flow in vessels, simulation of physiological functions, mathematical methods in medicine, propagation of blood pulse wave, PWV

DOI: 10.3233/JAE-2010-1180

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 735-742, 2010

Authors: He, W. | Luo, H.J. | Song, X.D. | Xu, Z.

Article Type: Research Article

Abstract: Magnetic induction tomography is considered to be valuable in medical application of testing brain edema. In this paper, we use the edge finite element method with electric field intensity E as the vector variable to simulate a multi-channel measuring system based on a real human brain finite element model. In simulation, we change the conductivity of brain edema and the frequency of exciting current to research the performance of the multi-channel measuring system in testing the …brain edema. Show more

Keywords: Magnetic induction tomography, edge finite element method, simulation

DOI: 10.3233/JAE-2010-1181

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 743-750, 2010

Authors: Demachi, Kazuyuki | Zhu, Haitao | Mizutani, Yurika

Article Type: Research Article

Abstract: The phase shift component of MRI image was simulated for the tumors including the ferromagnetic particles by DDS which yielded the magnetic field distortion around the tumors. The simulation clearly visualized the shape and position of tumors. This method can image selectively only the tumors including the ferromagnetic particles by DDS, and so will be useful for the early finding of small tumor that are difflcult to be found by coventional techniques.

Keywords: MRI, tumor detection, ferromagnetic particles, visualization

DOI: 10.3233/JAE-2010-1182

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 751-757, 2010

Authors: Xu, Zheng | Luo, Haijun | Wang, Junfeng | He, Wei

Article Type: Research Article

Abstract: A 4-layer concentric spherical model of human head was built to simulate the head EIT forward problem. The layers from outside to inside are scalp, skull, CFS (Cerebrospinal fluid) and brain tissue, respectively. A pair of point current sources placed on the outmost layer is regarded as the boundary condition, and an analytical method of separation of variables was employed to solve the problem. The electric potentials of different current injecting angles were calculated and the …equipotential lines were drawn. The simulation results revealed that, the increment of the brain tissue conductivity causes decrease of the magnitude of both real and imaginary parts of the electric potential on the scalp. The frequency property of the model was simulated, when the exciting frequency was increased, the imaginary part of the electric potential increased significantly. These analytical solutions could be used to analyze the head EIT problems and check the numerical solutions calculated from FEM or BEM. Show more

Keywords: Analytical solution, separation of variables, head EIT forward problem

DOI: 10.3233/JAE-2010-1183

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 759-768, 2010

Authors: Sun, Feng | Oka, Koich | Saibara, Yuuta

Article Type: Research Article

Abstract: This paper proposes a magnetic suspension system using a permanent magnet (PM) and a rotary actuator. In this suspension system, the suspension force is controlled by a variable magnetic flux path mechanism where the flux path is changed by varying the angle of the PM. The PM is magnetized in radial direction and driven by a rotary actuator. This system can change the magnetic polarity of the stator and generate a very small suspension force through …rotating the PM to some special angles. Since the fixed cores sustain the gravitational force of the suspended object and the rotary actuator has a larger reducer, this system also can generate a very big suspension force comparing with the input force. In this paper, first the prototype and the principle of this magnetic suspension system are explained. And in order to verify the proposed principle, the IEM (integral element method) analysis and basic experiments for magnetic flux density and attractive force are performed. The model is created, and the numerical simulation is carried out. Finally, suspension experiments are executed, and the results support our proposal. Show more

Keywords: Magnetic suspension, permanent magnet, rotary actuator, flux path control, IEM analysis

DOI: 10.3233/JAE-2010-1184

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 769-776, 2010

Authors: Du, Yumei | Jin, Nengqiang | Shi, Liming

Article Type: Research Article

Abstract: A controlled-PM Maglev system with permanent magnets and electromagnets excitation together can improve the lift/weight ratios, and reduce electromagnetic power consumption at the same air gap compared with a conventional electromagnetic attractive levitation system. It has been proved to be a very effective approach with great potential for application in magnetic levitation system. This paper analyses the magnetic force characteristics of linear synchronous motor in a controlled-PM maglev model vehicle system in …our lab with finite element method (FEM), presents the relationship between the magnetic forces and air gap at different current excitation, thrust-angle performance, and experiment results. Show more

Keywords: Linear synchronous motors, controlled-PM Maglev, hybrid maglev, magnetic force, FEM

DOI: 10.3233/JAE-2010-1185

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 777-784, 2010

Authors: Yamane, Ryuichiro | Kinoshita, Tetsuya | Park, Myeong-Kwan

Article Type: Research Article

Abstract: Magnetic levitation of molten metal can be simulated even in weak magnetic field by use of magnetic fluid as a surrounding fluid. The levitated liquid column is desirable to be stable, but it can be deformed or displaced from the equilibrium position. In the present research the disturbance is magnetically given to the liquid column and the excited oscillation is studied experimentally and analytically. The liquid column has inherent natural frequencies, and a kind of resonance …occurs at these frequencies, which will lead to the instability. Show more

Keywords: Magnetic fluid, levitation, instability

DOI: 10.3233/JAE-2010-1186

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 785-789, 2010

Authors: Tian, Yongsheng | Sun, Yanhua | Yu, Lie

Article Type: Research Article

Abstract: In magnetic thrust bearings (MTBs), eddy currents induced in the solid stator and thrust disk not only result in performance degrading of the bearing, but also influence the SRC of the coil when driven by a switching power amplifier. In this paper, a fractional differential equation (FDE) model of the SRC considering the effects of eddy current is proposed and a numerical solution can be obtained from it by a predictor-corrector algorithm. Results from finite element …method (FEM) and experiments show its validity. The presented model can be applied to the studies of self-sensing of non-laminated magnetic bearings. Show more

Keywords: Switching ripple current, fractional differential equation, FEM, magnetic bearing

DOI: 10.3233/JAE-2010-1187

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 791-799, 2010

Authors: Fan, Huiqing | Yang, Weiwei | Li, Chuang

Article Type: Research Article

Abstract: Electric and magnetic resonances of split-ring resonators (SRRs) as left-hand materials (LHM) were studied in a free space. Different copper thicknesses were designed to tune the electromagnetic resonance frequencies of SRRs. While the split gap width was varied, double-negative responses in SRRs were investigated in detail. Even both electric and magnetic resonance frequencies became higher as copper thickness was decreased, the electric resonance frequency increased much more higher with the increasing of the split …gap width. Show more

Keywords: Split-ring resonator, electric and magnetic resonant frequencies, gap width, copper thickness, left-handed materials

DOI: 10.3233/JAE-2010-1188

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 801-806, 2010

Authors: Choi, Jae-Hak | Chun, Yon-Do | Han, Pil-Wan | Koo, Dae-Hyun | Im, Jong-Bin | Lee, Ju

Article Type: Research Article

Abstract: This paper deals with the design of the structure and shape of writing probes in alternative electric data storage devices based on electric polarization fields. In order to design high recording density electric recording devices, the shape of the writing probe is optimized using a response surface methodology. The structure of a writing probe is also investigated according to the existence and nonexistence of the electric shield. The static and dynamic characteristic of recording density is …analyzed and compared with conventional recording devices based on the magnetic magnetization field. Show more

Keywords: Electric data recording, writing probe, response surface method, recording device

DOI: 10.3233/JAE-2010-1189

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 807-814, 2010

Authors: Luo, Jinglin | Yang, Baokun | Dong, Longlei

Article Type: Research Article

Abstract: Magneto-rheological (MR) damper is a smart damping device that can vary its damp with the change of magnetic field. Because of MR damper's exceptional characteristic, it has been widely used in many engineering fields, such as vehicle semi-active suspension control, seismic response reduction, weapon system, and so on. It is no doubt that the key to MR damper is magnetic circuit design. In this paper, a magnetic circuit design for a new structure MR damper (also …named as parallel-disks MR damper) is proposed, and the selection of materials, the calculation of coil turns and coil current is discussed. Finally, the design is analyzed with finite element method, and its effectiveness is verified. Show more

Keywords: Magnetic circuit design, parallel-disks MR damper, finite element analysis

DOI: 10.3233/JAE-2010-1190

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 815-822, 2010