International Journal of Applied Electromagnetics and Mechanics - Volume 60, issue 4

Authors: Xu, Meimei | Liu, Guohai | Chen, Qian

Article Type: Research Article

Abstract: This paper introduces a low torque ripple ferrite assisted synchronous reluctance motor (FASRM), in which an asymmetrical rotor is designed. The key of the proposed FASRM is to minimize the reluctance torque ripple, which is the main source of the total torque ripple. A compensation method is proposed to optimize the opening angle of each flux barriers, which indicates this pole producing torque with consistency in phase and waveform. Moreover, two existing motors with the same dimension are used as benchmarks in order to evaluate the proposed FASRM. Additionally, both theoretical analysis and simulation results are provided to validate the …good performances of the proposed FASRM. It is found that the proposed FASRM with the asymmetrical rotor can reduce the total torque ripple and avoid sacrificing the average torque. Show more

Keywords: Ferrite assisted synchronous reluctance motor, asymmetrical rotor, finite-element method, reluctance torque ripple

DOI: 10.3233/JAE-180084

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 479-488, 2019

Authors: Wang, Liping | Chen, Renwen | Ren, Long | Xia, Huakang | Zhang, Yuxiang

Article Type: Research Article

Abstract: A bistable magnetoelectric vibration energy harvester using nonlinear magnetic force is proposed. It consists of a planar spring, a magnetoelectric transducer with an annular magnetic circuit, and a coil assembly with a ferrite bobbin inside. Based on these, a nonlinear magnetic force between the ferrite bobbin and permanent magnet arrays can be generated when the relative displacement changes, which can broaden the operating frequency bandwidth of the harvester. The nonlinear magnetic force makes the harvester demonstrate some special dynamic behaviors including the inter-well and chaotic motions, which are performed by the finite element analysis. And, the experimental validations are also …carried to verify the performance of the proposed harvester. The results show that the output power can reach 10 mW in a relatively wide operating frequency range with a 90 Ω resistance load under 1 g harmonic excitation. In addition, a real vehicle road’s vibration signals from a highway bridge are acquired to estimate the practical energy harvesting performance of the harvester. The results show that the RMS output voltage and load power of the harvester can reach 3.16 V and 110.95 mW under 10× road spectrum excitations, respectively. Show more

Keywords: Vibration energy harvester, broadband, magneto electric, nonlinear magnetic force, bistable

DOI: 10.3233/JAE-180074

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 489-502, 2019

Authors: Al Eit, Moustafa | Clénet, Stéphane | Henneron, Thomas | Guyomarch, Féderic

Article Type: Research Article

Abstract: In this paper we present a-priori model reduction technique that enables to take full advantage of the periodicity existing in the stator and rotor geometrical structures of electrical machines in order to reduce the computational time. Firstly, a change of basis is performed by applying two distinct discrete Fourier transformations on the stator and rotor periodic structures independently. Secondly, the Schur complement is introduced in the new spectral basis, to allow a parallel solving of the resulting block-diagonal matrix systems. Moreover, the using of a matrix-free Krylov method based on the conjugate gradient solver has verified an efficient solving of …the equation system associated to the stator-rotor interface. Furthermore, in the peculiar case of balanced supply conditions, a model order reduction can be carried out by considering only the dominant discrete Fourier transform components. This model reduction approach is applied on a buried permanent magnet machine and has successfully shown its efficiency under balanced and unbalanced conditions. Show more

Keywords: Finite-element analyses, model reduction, geometrical periodicity, discrete Fourier transform, electromagnetic fields, rotating electrical machines, buried permanent magnet machines, Schur complement

DOI: 10.3233/JAE-180067

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 503-528, 2019

Authors: El Wahed, Ali K. | Balkhoyor, Loaie B. | Wang, HaoChen

Article Type: Research Article

Abstract: In this paper, the design and performance of a multi-degree-of-freedom smart ball-and-socket actuator and its application to rehabilitation training systems are investigated. A key feature of this actuator is the use of magnetorheological fluids which can exhibit dramatic changes in their rheological properties, including yield stress, when subjected to external magnetic fields. These fast and reversible fluid rheological changes permit the smart actuator to provide the required impedance at orthotic arm joints aimed for upper-limb rehabilitation. Electromagnetic finite element analyses using ANSYS software were carried out to design the electromagnetic circuit of the actuator and important design factors affecting …the efficiency of the generated magnetic field and its best delivery to the MR fluid, were examined. These factors included the relative permeability of the magnetic material and the electromagnetic coil properties such as its shape, size and location. In addition, the utilisation of non-magnetic materials in the electromagnetic circuit design was investigated with the aim to optimise the performance of the smart actuator. Finally, the performance of the smart actuator was assessed theoretically and numerically under various input conditions in which Bingham plastic fluid characteristics were assumed, and the results determined by the two techniques were found to compare well. Show more

Keywords: Magnetorheological fluids, electromagnetic design, ball-and-socket actuator

DOI: 10.3233/JAE-170039

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 529-544, 2019

Authors: Liu, Zenghua | Zhang, Yongchen | Li, Aili | Xie, Muwen | Bin, Wu | He, Cunfu

Article Type: Research Article

Abstract: With the non-dispersion characteristics, the lowest shear horizontal mode SH0 can be widely applied in the detection and monitoring of a defect in plate structures. In order to achieve SH0 mode excitation in aluminum plates, based on Lorentz force mechanism, a new directional SH0 mode EMAT based on periodic grating coil (PGC), called PGC-EMAT, is designed in the study. On the surface of the aluminum plate, the PGC produces the horizontal eddy current. The oppositely induced eddy currents are generated by the adjacent grating units. The current I of the multiple wires in each grating unit …is the same. The rectangular magnet provides the static magnetic field perpendicular to the surface of the aluminum plate. In addition, the PGC-EMAT with different grating units of the periodic grating coil and coil layers are simulated by three-dimensional finite element simulation. The simulation results show that with the increase of grating units of the periodic grating coil, the tangential displacement of PGC-EMAT will increase, and the tangential displacement of double-layer periodic grating coil is larger than that of single-layer periodic grating coil when the number of grating units of the periodic grating coil is the same. The developed EMAT can excite and receive a single SH0 mode and the actual center frequency of the transducer coincides with the theoretical value. It was proved that the central frequency of the transducer was controlled by the distance between the adjacent grating units of the periodic grating coil. In order to increase the energy of the signals excited or received by PGC-EMAT, the number of cycles of grating units and the number of layers of the transducer were studied. The experimental results showed that there was a linear relationship between the number of cycles of the grating units and the energy of the excited and received signals. The energy of the excited and received signals of the double-layer PGC-EMAT was larger than that of the single-layer PGC-EMAT when PGC-EMAT was used as excitation transducer or receiving transducer. The simulation results were experimentally verified. The developed PGC-EMAT can be applied in defect detection. Show more

Keywords: Ultrasonic guided waves, shear horizontal mode, electromagnetic acoustic transducer, periodic grating coil, metal plate

DOI: 10.3233/JAE-180120

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 545-563, 2019

Authors: Zhang, Jian-ping | Wang, Shuai | Xu, Da-cheng | Hu, Dan-mei | Wu, Helen

Article Type: Research Article

Abstract: In order to investigate the PM2.5 collection efficiency of a wire-cylinder electrostatic precipitator (ESP) under the action of ionic wind, PM2.5 removal mechanism was studied, and an ESP mathematic model including the multi-field coupling between gas flow field, electric field and particle dynamical field was built. By applying Deutsch-Anderson Equation to process and analyze the numerical solution after compiling user-defined function (UDF) program and linking it to Fluent, grade collection efficiency and overall collection efficiency for PM2.5 were obtained. Numerical results indicate that PM2.5 removal performance under the consideration of ionic wind is better, and the contribution of ionic wind …to PM2.5 removal performance is different by changing operating voltage and gas velocity. The research results can provide references for researchers to design a novel wire-cylinder ESP. Show more

Keywords: Multi-field coupling, wire-cylinder ESP, ionic wind, PM2.5, removal performance

DOI: 10.3233/JAE-180095

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 565-577, 2019

Authors: Wu, Jian | Sun, Jikang | Zhang, Tao | Sun, Hongbing | Ji, Sai | Sun, Yajie

Article Type: Research Article

Abstract: At present, the sampling rate in a wireless sensor network is generally low, which does not meet the requirements for high-speed sensor signal acquisition and detection. To address the shortcomings of wireless sensor networks in terms of the design methods and effects assessment, a high-speed wireless sensor network node was designed based on structural health monitoring. Based on the general framework of a wireless sensor node, combined with the requirement of active health monitoring, a test of screws loosening in a reinforced aluminum plate were conducted. The theory of compressed sensing was used to test the effects of compressed sampling …for the high-speed acquisition nodes. The results demonstrated that high-speed wireless sensor nodes could complete active excitation, sampling, and processing of the response signal for the application of active structure monitoring with integrated software and hardware and that the system could distinguish the looseness of the screws in the aviation specimens accurately. The nodes also met the requirements of small size, low cost, and low power consumption. The results of the experiment verified that the hardware and software modules for the high-speed wireless sensor nodes functioned and monitored the structural damage effectively. The system solves many key problems of node design in wireless sensor networks in the industrial field. Show more

Keywords: Wireless sensor network (WSN), structural health monitoring (SHM), high-speed sampling

DOI: 10.3233/JAE-170051

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 579-601, 2019

Authors: Kim, Hong-seok | Kwon, Jung-woo | Kwon, Byung-il

Article Type: Correction

DOI: 10.3233/JAE-191919

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 60, no. 4, pp. 603-603, 2019