International Journal of Applied Electromagnetics and Mechanics - Volume 63, issue 2

Authors: Bu, Wenshao | Tu, Xiaowan | Lu, Chunxiao | Pu, Yi

Article Type: Research Article

Abstract: In order to solve the unbalanced vibration problem of bearingless induction motor caused by the rotor mass eccentricity, an adaptive feedforward vibration compensation control strategy is researched. Firstly, the inverse dynamic decoupling control method of torque system and the steady-state stochastic displacement feedback control of magnetic suspension system are introduced in brief. Then the feedforward compensation control strategy of unbalanced vibration displacement is discussed, taking the minimum mean square error of rotor radial displacement as a goal, an adaptive feedforward compensation control algorithm for unbalanced vibration displacement is designed, and by changing the amplitude and phase of the compensation signal …of unbalanced vibration displacement step by step iteratively, the influence of periodic unbalanced excitation force is suppressed or counteracted. Finally, the feedforward compensation control method is simulated and validated, and the influence of the detection deviation of motor speed on the vibration compensation effect is analyzed. The simulation experiment results show that the adaptive feedforward vibration compensation control strategy can significantly suppress the unbalanced vibration displacement during the sudden change of motor speed, and can eliminate the unbalanced vibration displacement in the steady state, and then the suspension control accuracy of the rotor is greatly improve. Show more

Keywords: Bearingless induction motor, unbalanced vibration displacement, adaptive feedforward vibration compensation, step by step iteratively

DOI: 10.3233/JAE-190092

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 199-215, 2020

Authors: Si, Zhanchao | Yang, Fan | Yao, Degui | Zhang, Guangzhou | Kou, Xiaoshi | Gao, Bing | Feng, Zhihui

Article Type: Research Article

Abstract: The UHV transmission lines usually have large regional spans and involve various weather conditions, which will have different effects on the circuit design and electromagnetic environment. However, the existing research lacks the ion flow field analysis of AC and DC parallel lines under different weather conditions. Hence, we studied the distribution law of the ion flow field of ±800 kV DC and 500 kV AC parallel transmission lines under different weather conditions, and compared the calculated results with measured results. First, we used the meshless method to model the ion flow field of AC and DC parallel lines in different weathers. Then, …the influence of environmental factors on the ion flow field was analyzed. The effects of temperature, humidity and haze on the distribution of the ion flow field were obtained based on long-term monitoring and measurement. Results show that the ion flow field of the theoretical calculation results was basically in accord with the actual measurement. The ion flow field of parallel lines increases with the rise of temperature, first increases and then decreases with the rise of humidity, and increases with the rise of haze. Show more

Keywords: Ion flow field, weather conditions, parallel lines, meshless method

DOI: 10.3233/JAE-190113

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 217-228, 2020

Authors: Aguilar, Arturo | Rubio, José de Jesús | Meda-Campaña, Jesús A. | Martinez, Dany Ivan | Vargas, Tomas Miguel | Garcia, Victor | Novoa, Juan Francisco | Mujica-Vargas, Dante | Pacheco, Jaime | Gutierrez, Guadalupe Juliana

Article Type: Research Article

Abstract: In this article, the mathematical model of a machine with eight immovable magnets and two movable magnets, and the machine with four immovable magnets and two movable magnets are introduced for the electricity creation. The proposed machines are based on the machine with two immovable magnets and two movable magnets, but they have two main differences: they have more interactions between the immovable and movable magnets, and they create more electricity. Experiments are included to validate that the proposed mathematical models represent a prototype and to observe which machine creates more electricity.

Keywords: Machines, immovable magnets, movable magnets, electricity creation, mathematical models

DOI: 10.3233/JAE-190087

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 229-248, 2020

Authors: Wang, Shaopeng | Ma, Jinguang | Liu, Chengcheng | Wang, Youhua | Lei, Gang | Guo, Youguang | Zhu, Jianguo

Article Type: Research Article

Abstract: To improve output torque ability and reduce torque ripple in traditional synchronous reluctance motor (TSynRM), a new synchronous reluctance motor (NSynRM) is proposed in this paper. The rotor of NSynRM is composed of both grain-oriented silicon steel and non-oriented silicon steel. With the reasonable design of rotor structure, the torque of NSynRM has been improved and its torque ripple has been reduced greatly. Firstly, TSynRM and NSynRM are qualitatively compared by using the magnetic network method. Secondly, the main parameters of these two machines are optimized by using finite element method (FEM). Then the performance comparison between two optimized machines …are carried out. Finally, the equivalent stress of these two machines at the maximum speed are analyzed. It can be seen that NSynRM can have 6.8% higher torque under rated load, 8% higher torque under maximum load, 17.5% wider constant torque operation region, and lower torque ripple compared with the TSynRM. Show more

Keywords: Synchronous reluctance machine, grain-oriented silicon steel, reluctance torque, magnetic network analysis, finite element method

DOI: 10.3233/JAE-190109

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 249-265, 2020

Authors: Shen, Sheng | Wu, Jiamin | Guo, Pan | Wang, Hongyi | Chen, Fangge | Meng, Fanqin | Xu, Zheng

Article Type: Research Article

Abstract: Comparing with superconducting and permanent magnet magnetic resonance imaging (MRI) system, ultra-low- field MRI (uMRI) system has a much lower weight, which can be used in some special scenes, such as real-time image monitoring on bedside or in the ambulance for human brain disease (stroke). In order to make the uMRI system more compact, lighter, and smaller, in this work, we proposed a hybrid method for designing uMRI electromagnet. The method consists of integer linear programming (ILP) and nonlinear optimization, which were bridged by empirical principles. ILP was used to determine the coil distribution of uMRI electromagnet. Considering that the …coil distribution, acquired with ILP, is not conducive for magnet processing, two empirical principles were applied to adjust the coil distribution with decreasing electromagnet performance as little as possible. At last, nonlinear optimization was exploited to eliminate the negative influence on magnetic field distribution which is introduced by coil adjustment and make electromagnet satisfy the design requirement of magnetic field homogeneity. This hybrid method combines mathematical models and empirical principles, which provides a way to design electromagnet efficiently. A small electromagnet with homogeneity of 10 ppm in a spherical region of interest (ROI) with diameter of 80 mm is designed and built in this paper. Show more

Keywords: Ultra-low-field MRI, electromagnet design, integer linear programming, nonlinear optimization

DOI: 10.3233/JAE-190051

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 267-278, 2020

Authors: Eldabe, Nabil Tawfik | Moatimid, Galal M. | Sayed, Aya

Article Type: Research Article

Abstract: The manuscript examines the motion of an Eyring–Prandtl nanofluid inside a horizontal asymmetric peristaltic nonuniform channel. A normal variable magnetic field affects the channel. The slip boundary-conditions are taken into consideration. The boundary-value problem involves the energy as well as the concentration equations. The viscous dissipation of the thermal equation is considered. The flow is immersed in a porous medium. The governing equations of motion are solved by means of the Homotopy perturbation method (HPM). The distributions of the various functions are analytically obtained. The influences of the different parameters are authenticated throughout a set of diagrams. It is found …that thermal-diffusion (Soret), diffusion-thermo (Dufour), Lorentz resisting force and induced magnetic have active effects on the distributions of the nano-particle; such as, concentration volume, temperature, and flow characteristics. Show more

Keywords: Eyring–Prandtl model, peristaltic transport, induced magnetic field, porous media, heat and mass transfer

DOI: 10.3233/JAE-190131

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 279-298, 2020

Authors: Guo, Liyan | Geng, Qiang | Chen, Wei | Wang, Huimin

Article Type: Research Article

Abstract: This paper proposes a kind of low iron-loss variable flux permanent magnet memory machine. The proposed memory machine can expand the speed range of machine, guarantee the operation efficiency of machine, avoid the irreversible demagnetization of PMs under high speed, and decrease the iron loss of the machine. Further, Taguchi method is used to optimize the proposed low iron-loss PM memory machine under magnetizing and demagnetizing current pulses respectively. Finally, the final optimum design scheme for the proposed low iron-loss variable flux permanent magnet memory machine is achieved by giving consideration to each optimization objective.

Keywords: Variable flux permanent magnet memory machine, iron loss, flux linkage, Taguchi method, magnetizing and demagnetizing current pulses

DOI: 10.3233/JAE-190073

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 299-313, 2020

Authors: de Souza, Ivan Alves | de Medeiros Neto, Joao Freire | Nascimento, Igor Oliveira | Matamoros, Efrain Pantaleon | Feitor, Michelle Cequeira | Fernandes, Fernanda de Melo | Magalhães Sousa, Rômulo Ribeiro | de Carvalho Costa, Thércio Henrique

Article Type: Research Article

Abstract: This work aimed to characterize a Dielectric Barrier Discharge (DBD) plasma equipment through optical and electrical measurements, seeking to obtain a greater knowledge of the plasma production process and how it behaves through the adopted parameters, such as frequency and voltage applied between electrodes, at a fixed distance of 1.7 mm. In order to measure them, three different characterization techniques were applied. The first method was the Lissajous figures, a technique quite effective for a complete electrical characterization of DBD equipment. The second technique used was the Optical Emission Spectroscopy, a tool used for the diagnosis of plasma, being it …possible to identify the excited species produced in discharge in diffuse and filamentary regime in the plasma. And finally, the triple Langmuir probe technique was used to obtain the electron temperature and electron density. Based on this study, it was possible to identify the equipment efficiency in different regimes. The electron temperature measurement for both systems analyzed were 27.96 eV and 20.69 eV to the filamentary and diffuse regimes, respectively. The density of electrons number to these regimes were 1.09 × 1021 m−3 and 1.56 × 1021 m−3 . Show more

Keywords: Lissajous figures, electron temperature, electron density, triple Langmuir probe

DOI: 10.3233/JAE-190044

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 315-325, 2020

Authors: Zhang, Yuxiang | Chen, Renwen | Liu, Chuan | Wang, Liping | Qin, Jinchang

Article Type: Research Article

Abstract: Research on renewable energy have become a focus in recent years. Ocean wave energy is a kind of renewable energy that exists widely in the world. This paper presents a snake-like ocean Wave Energy Converter (WEC) , which is more adaptive to the wave shape than some other WECs. In order to improve energy conversion efficiency, we designed and tested three types of magnetoelectric transducers for snake-like WEC, namely, axial magnetization transducer, radial magnetization transducer and Halbach permanent magnet array transducer. In order to enhance the power density of the WECs, a lumped parameter equivalent magnetic circuit model is proposed …to optimize its magnetic structural parameter. Then the finite element analysis method is used to analyze models and verify theoretical results. Three 1:5 prototypes of the magnetoelectric transducers are fabricated for experimental verification. The experiments indicate that the prototype with the Halbach permanent magnets array transducer has an output power of 693.80 mW when WEC moves at a relative velocity of 0.1 m/s, the V RMS value of induced voltage is 6.69 V. and this prototype has the highest volumetric Figure of Merit (FoM v ) of 1.67%. In conclusion, the Halbach permanent magnet array is more effective in energy conversion than the others, and it can effectively improve the energy harvesting performance for the snake-like WEC. Show more

Keywords: WEC, snake-like, Halbach, equivalent magnetic circuit model, finite element analysis

DOI: 10.3233/JAE-190077

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 327-342, 2020

Authors: Gao, Peng | Gu, Yuxi | He, Yuling | Gerada, David | Wang, Xiaoyuan | Gerada, Chris

Article Type: Research Article

Abstract: Metallic sleeves are widely used to ensure the mechanical integrity of rotors in high-speed permanent magnet (PM) synchronous machines (HSPMSM). However, in traditional high-speed rotors, the PMs which are very weak in tensile stress cannot be well protected by sleeves. Furthermore, the material properties of both the sleeves and PMs cannot be fully used. As a result, the high-speed running range of the machines are limited by the mechanical strength for a given rotor size. In this paper, taking a 230-kW 35-kr/min prototype as an example, the mechanical strength issues of the rotor are investigated by analytical method and finite …element analysis (FEA). In order to overcome the unbalanced protective effect of the sleeve and make fully use of the materials, an optimal sleeve, as well as an improved rotor structure, is presented. The comparison results show that the optimized sleeve has well balanced protective effect to the PM as well as good utilization of materials, with a resultant increase in maximum speed of nearly 40% with respect to the prototype. Show more

Keywords: High-speed, permanent magnet synchronous motors (PMSM), metellic sleeve, stress

DOI: 10.3233/JAE-190103

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 63, no. 2, pp. 343-359, 2020