International Journal of Applied Electromagnetics and Mechanics - Volume 56, issue 1

Authors: Liu, Bendong | Zhang, Zhen | Yang, Jiechao | Yang, Jiahui | Li, Desheng

Article Type: Research Article

Abstract: In this paper, an electromagnetically actuated tube type micropump is proposed, conceptually designed and experimentally investigated. The micropump mainly consists of two electromagnets, a NdFeB permanent magnet, a ball-valve and a Teflon tube. The reciprocating movement of the permanent magnet is realized when the two electromagnets excitated alternatively. The liquid in the tube flows from the inlet to the outlet while the permanent magnet reciprocating in the tube regulated by a one-way valve. Maximal flow rate of 208.75 μ L/min and maximum backpressures of 539 Pa were achieved at a applied current of 0.5 A when the actuation …frequency is 5 Hz. Compared to other micropumps with membrane structure driven by an external electromagnetic actuator, the tube type micropump is more reliable, small in volume, easy to be fabricated and has zero dead volume and less turns of coil. Show more

Keywords: Micropump, electromagnetically actuated, tube type, ball-valve

DOI: 10.3233/JAE-160143

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 1-9, 2018

Authors: Liu, Jing | Ma, Tingfeng | Du, Jianke | Wang, Ji | Yang, Jiashi

Article Type: Research Article

Abstract: We propose using a circular driving electrode on a conventional thin film bulk acoustic wave resonator with a square piezoelectric film on a square ground electrode and a square dielectric layer. The circular driving electrode has the advantage of avoiding the electric field concentration at the corners of a square driving electrode and the related negative effects. A circular driving electrode is also perfectly consistent with the in-plane material isotropy of common thin film resonator materials such as AlN and ZnO. A theoretical analysis on the proposed resonator was performed to obtain the basic vibration characteristics including resonant frequencies and …mode shapes. Show more

Keywords: Piezoelectric, plate, resonator, vibration

DOI: 10.3233/JAE-170014

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 11-19, 2018

Authors: Abdalla, I.I. | Ibrahim, T. | Nor, N.M. | Perumal, N.

Article Type: Research Article

Abstract: As compared to other renewable energy technologies, the ocean waves are huge, largely untapped energy resource, and the potential in extracting energy is considerable. There is a lack of convergence on the best method of extracting energy from the waves, despite previous innovations, which has generally focused on the concept and design of the wave energy converter (WEC) technology, making the strategies for enhancing the efficiency of WECs important. This paper presents the performance analysis and design optimization of a single-slotted permanent-magnet linear generator. The magnetic field distribution in a cylindrical coordinate has been established. The magnetic field provides a …prediction for the thrust force, flux-linkage and back-electromotive force (B-EMF), and also facilitates the characterization of the proposed machine as well as provides a basis for design optimization and dynamic modeling of the system. Finite Element Analysis (FEA) has been used for the design optimization of the proposed generator. The proposed generator has been optimized with respect to the leading design parameters R m / R e and T m ⁢ r / T P . Thus, from the results, it can be observed that the generator has a very good efficiency to serve as WEC. Show more

Keywords: Tubular permanent-magnet linear generator, finite element analysis (FEA), wave energy converter

DOI: 10.3233/JAE-170022

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 21-34, 2018

Authors: Bu, Wenshao | Huang, Yongquan | Lu, Chunxiao | Zhang, Haitao | Shi, Haitao

Article Type: Research Article

Abstract: Aiming at the unbalanced vibration problem of bearingless induction motor caused by the rotor mass eccentricity, an adaptive LMS extraction method of unbalanced displacement is proposed. Firstly, the characteristics of unbalanced displacement signal, the influences of step size factor on the tracking speed and the steady state tracking error are analyzed; then in order to solve the contradiction between tracking speed and steady state tracking error, and achieve the quick extraction of unbalanced displacement, a convenient nonlinear function of step size factor is adopted. On this basis, an unbalanced vibration control system of a bearingless induction motor is constructed; simulation …verification and analysis are made. The simulation results have shown that the unbalanced displacement signal can be extracted quickly in dynamic status, a higher extraction precision of unbalanced displacement can be obtained in steady status; based the proposed extraction method of unbalanced displacement signal, the magnetic suspension control performance of a bearingless induction motor can be improved greatly. Show more

Keywords: Bearingless induction motor, unbalanced displacement, extraction of characteristic signal, variable step size LMS algorithm, compensation for unbalanced excitation force

DOI: 10.3233/JAE-170061

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 35-47, 2018

Authors: Cao, Guanghua | Wang, Chen | Huang, Jinlin

Article Type: Research Article

Abstract: The cogging torque in stator permanent magnets axial-field flux-switched hybrid excitation motor (SPMAFHEM) is larger than the traditional PM machine because of the flux focusing. In order to reduce cogging torque and improve the performance of the motor, the analytic expression of the SPMAFHEM cogging torque is deduced by energy perturbation method and the influence of the structure parameters on cogging torque is researched. Based on response surface methodology (RSM) and FEM, the mathematical model of cogging torque response surface between stator slot arc width, rotor tooth inclination angle, and shape coefficient of permanent magnet is obtained, then the cuckoo …search algorithm (CS) is used to search the optimum solution. The accuracy is examined by 3D FEM and experiments using prototype experimental platform. The results show that the cogging torque has been reduced by 82.5%. Show more

Keywords: 3D FEM, cuckoo search algorithm (CS), cogging torque, flux switching, optimization, response surface methodology (RSM)

DOI: 10.3233/JAE-170078

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 49-61, 2018

Authors: Liu, Guangdou | Wang, Yanzhe | Xu, Xingping | Ming, Wuyi

Article Type: Research Article

Abstract: In this paper, the changing of magnet shape in Halbach magnet array of planar motor is analyzed for the magnetic flux density. It is the rectangular magnets that are replaced by pyramidal magnets. The magnetic flux density of Halbach magnet array with rectangular magnets is derived by Fourier series and scalar potential. The magnetic flux density of pyramidal magnet array is obtained through superposition and dividing the magnet array in several layers. Then the harmonic model has good agreement with the finite element model (FEM) by comparing the z -component of magnetic flux density. The division layer p …is decided by analyzing the amplitude error of z -component of magnetic flux density between harmonic and FEM. The pyramidal magnet array is analyzed from the items such as the waveform, peak value and total harmonic distortion (THD) of z -component of magnetic flux density. Above all, the smaller the rotation angle is, the bigger the peak value of z -component of magnetic flux density will be obtained and the smaller the total harmonic distortion will be simultaneously achieved. Show more

Keywords: Halbach array, peak value, planar motor, pyramidal magnet, THD

DOI: 10.3233/JAE-170090

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 63-73, 2018

Authors: Zeng, Shuo | Liu, Yaozong | Li, Jun

Article Type: Research Article

Abstract: Almost all existing analytical formulae describing the magnet-rail relationship for maglev trains have been derived with the assumption that magnetic media operate within the linear zone of the B-H curve and, therefore, over-predict the levitation and guidance forces when the magnetic media are in their saturation states. In such cases, finite element simulations are commonly used to obtain an accurate solution of the electromagnetic force, but this process is time-consuming. In this study, metamodels suitable for saturated magnetic media are constructed based on the methods of uniform design and stepwise regression, and their performance is assessed in terms of data …fitting and prediction accuracy. Show more

Keywords: Magnetic saturation, magnet-rail relationship, levitation force, guidance force, uniform design, stepwise regression, metamodeling

DOI: 10.3233/JAE-170102

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 75-89, 2018

Authors: Sun, Pan | Zhou, Yu | Wu, Xusheng | Sun, Zhaolong | Gao, Wei | Jiang, Chaoli

Article Type: Research Article

Abstract: In this paper, magnetic force and vibration in low-speed surface-mounted permanent magnet (PM) machines accounting for eccentric and concentric magnet poles are investigated. It is shown that the number of harmonics and total harmonic distortion (THD) of radial flux density and radial force density, cogging torque, and displacement of stator core in concentric PM machine are much bigger than those in eccentric PM machine. The eccentric magnetic pole is helpful to reduce vibration and acoustic noise. And the ratio of the mean square error of the radial force on the teeth of the two prototype machines are approximately equal to …the ratio of the peak-peak value of the displacement at the outer periphery of the stator core of the two prototype machines. Show more

Keywords: Permanent magnet machines, magnetic field, eccentric, cogging torque, radial force, displacement

DOI: 10.3233/JAE-170107

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 91-102, 2018

Authors: Yu, Qiang | He, Chang | Tian, Lisi | Wang, Xuesong | Cheng, Yuhu

Article Type: Research Article

Abstract: In this paper, a simple magnetic circuit network model is proposed to simulate saliency and can-shield effect with high magnetic saturation for a double salient canned switched reluctance machine. The saliency effect, including rotor position dependent airgap paths and magnetic saturation on poles, is described by discretized and adaptable magnetic reluctance elements. Further, can-shield impact due to electromagnetic coupling in airgap is described by Faraday law of energy conversion. Such a network is featured by adopting characteristic magnetic paths without empirical equations and is applicable to various machine geometries without power density limit.

Keywords: Switched reluctance machine, canned machine, saliency, magnetic equivalent circuit, magnetic saturation, flux linkage

DOI: 10.3233/JAE-170109

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 103-113, 2018

Authors: Su, Bokai | Sun, Xiaodong | Chen, Long | Yang, Zebin | Li, Ke

Article Type: Research Article

Abstract: This paper deals with the thermal modeling and analysis of bearingless permanent magnet (PM) synchronous motors (BPMSMs). A thermal model of the BPMSM is proposed with considering eddy current loss of PMs, copper loss as well as core loss of the stator. To enhance the accuracy of the thermal analysis, core losses of stator core and eddy current losses of PMs are calculated by finite element method (FEM). Furthermore, the heat source, equivalent thermal conductivity of stator/rotor core, equivalent insulation of stator windings insulation, equivalent thermal conductivity of the air gap, and convection coefficients in each motor surface are considered. …Finally, the temperature distributions of the BPMSM in three different operation conditions are analyzed in detail. According to the simulation results, it is found that the overheat on PMs and all windings will happen during the peak power condition, and simulation results can provide further basis for the design of BPMSMs, such as insulation level of the winding, the selection of the PMs and the cooling system. Moreover, it lays the theoretical foundation on further studies. Show more

Keywords: Thermal modeling, bearingless permanent magnet synchronous motor (BPMSM), finite element method (FEM), operation condition

DOI: 10.3233/JAE-170112

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 115-130, 2018

Authors: Zhang, Shuai | Li, Wenlong | Zhang, Xueying | Wang, Hongbin | Zhao, Mingkang | Li, Zixiu | Xu, Jinzhao | Xu, Jiayue | Cui, Kun | Shi, Xun | Tan, Chunxiao | Xu, Guizhi

Article Type: Research Article

Abstract: Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) is a hybrid imaging modality proposed to reconstruct the electrical impedance property in biological tissue with high spatial resolution. The tissue in most parts of human body has inhomogeneous acoustic properties, which will significantly affect the propagations of ultrasound waves. And then it leads to potential distortion and blurring of the acoustic source and conductivity images in the reconstruction. The purpose of this paper is to reconstruct both the acoustic source and conductivity distribution in an acoustically heterogeneous medium. And a new algorithm is presented based on the generalized finite element method (GFEM) and …inhomogeneous time reversal method. We established an acoustic inhomogeneous model, in which different regions of the model the acoustic signals spread with different speeds. The numerical simulation experiments showed feasibility of the new method. Then we applied the proposed algorithm to reconstruct the conductivity of a gel phantom with our MAT-MI system. The experimental results indicate that the acoustic inhomogeneity of tissues in terms of speed variation can be reconstructed in the process of MAT-MI imaging. Show more

Keywords: MAT-MI, acoustic inhomogeneity, time reversal method

DOI: 10.3233/JAE-9170095

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 131-140, 2018

Authors: Chen, Dezhi | Fang, Liwei | Zhao, Wenliang | Bai, Baodong | Kwon, Byung-Il

Article Type: Research Article

Abstract: In this paper, a design scheme for a novel energy-saving contactor using two-phase magnetic material is presented. A magnetization model using two-phase magnetic material was built with mathematical modeling and the theory of the Preisach model. The conversion mechanism was analyzed in order to reveal the relationship between the remanence and coercivity. The manufacturing process of the material is also described. Based on the differences between the transformation characteristics of the two-phase magnetic material in the permanent magnet and the soft magnetic field, an energy-saving contactor was designed by using two-phase magnetic material based on the remnant magnetism of 75 …Oe. The simulation and experiment results show that the proposed energy-saving contactor functions well. Show more

Keywords: Two-phase magnetic material, hysteresis model, energy-saving contactor

DOI: 10.3233/JAE-9170096

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 56, no. 1, pp. 141-149, 2018