International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Yan, Dong | Guo, Liyan | Shi, Tingna | Wang, Huimin | Yan, Yan | Xia, Changliang

Article Type: Research Article

Abstract: The split ratio is one of the most important design parameters of the machines and has a significant effect on the electromagnetic performance. Using the split ratio, this paper presents a performance analysis method for permanent magnet (PM)-assisted reluctance machine is presented. An accurate analytical model, which considers the saturation of outer iron ribs and the asymmetric saturation of rotor islands, is firstly proposed. In order to reduce the numbers of the adjustable structural parameters during the initial design process and ensure the independence among the parameters, a geometric structure corresponding to the split ratio is then established. The effectiveness …of the proposed analytical model based on the split ratio is verified by FEM, and applied to analyze the electromagnetic performance for the three-flux-barrier PM-assisted reluctance machines. On the basis of the analysis results, the design scheme corresponding to the optimal split ratio, which makes the machine obtain a higher efficiency and guarantees the PMs without irreversible demagnetization, is determined rapidly. Show more

Keywords: Permanent magnet (PM)-assisted reluctance machine, the gradient flux barrier, split ratio, analytical model

DOI: 10.3233/JAE-190104

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-25, 2019

Authors: Yan, Xinxiao | Li, Yongjian | Cheng, Zhiguang | Zhang, Changgeng

Article Type: Research Article

Abstract: A 3-D coupled magneto-fluid-thermal model is established for temperature rise prediction in a ventilated dry-type transformer rated at 2500 kVA. In order to accurately estimate electromagnetic losses, a three-dimensional (3-D) transient finite element method considering the effect of eddy-current losses on the foil type windings is proposed. Besides, two orthogonal B -P loss curves are adopted to model the anisotropy of grain-oriented (GO) silicon steel. The non-uniform power losses of winding and core are mapped into the thermal field as heat sources. Moreover, the transformer structures such as the narrow struts, insulation barrier and clamps are considered to improve the …computational accuracy of air velocity and temperature distribution. At last, the test of temperature rise has been carried out to verify the proposed model. Show more

Keywords: Dry-type transformer, eddy currents, power losses, magnetic measurements

DOI: 10.3233/JAE-190054

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2019

Authors: Zhao, Jianhui | Yue, Pengfei | Wei, Kebiao

Article Type: Research Article

Abstract: A high-speed solenoid valve (HSV) with high dynamic responses is a key component of the common rail injector, where it provides accurate and flexible control of the injection. In this study, finite element methods were used to investigate the eddy current inside an HSV. The results demonstrated that the appearance and change in the eddy current were related to the driving current, and significantly influenced the HSV dynamics, particularly the opening response. By considering the eddy current effect, the calculations were seen to match the experimental data effectively during the opening response, but did not match them strongly during the …closing response. During the HSV opening process, the eddy current at the surface of the magnetic materials impeded the magnetization; during the closing stage, it prevented the magnetic flux inside the magnetic material from spreading out and delayed demagnetization. An eddy current was proven to always block the magnetic field change and worsen the HSV dynamic response. Slotting on the yoke can significantly reduce the open response time, while hardly influence the close response. It was deemed necessary to optimize the HSV structure to weaken the eddy current effect on the opening and closing response. Show more

Keywords: eddy current effect, dynamic response, high-speed solenoid valve, common rail injection system, diesel engine

DOI: 10.3233/JAE-190047

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2019

Authors: Guo, Yujing | Jin, Ping | Ding, Yan | Zhao, Kai | Issoufou, Abdoul Zaid

Article Type: Research Article

Abstract: In this paper, one kind of U-shape permanent magnet embedded salient pole wind generator is proposed. The permanent magnet is divided into three sections to form a U-shaped structure and inserted into the salient pole in the generator. The size of the PM near the side frame is small, therefore, there is sufficient PM location modification space in the salient pole. Some flux-barriers are set in the upper core of the salient pole, which can reduce the q -axis inductance, and ultimately increases the generator maximum output power. To evaluate the generator’s overall performance, some other important electromagnetic parameters such …as the air-gap flux density, the output voltage, the cogging torque, the output power, and the demagnetization performance are all calculated and analyzed base on finite element method (FEM). All the above parameters are compared with that of one V-shape permanent magnet embedded salient pole wind generator. The analysis results show that, with the same volume of permanent magnet, the proposed U-shape permanent magnet embedded salient pole wind generator has higher power density than the V-shape permanent magnet embedded salient pole wind generator. Show more

Keywords: Electromagnetic parameter analysis, reluctance power, salient pole, wind generator

DOI: 10.3233/JAE-190026

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2019

Authors: Sun, Hongyu | Wang, Shen | Huang, Songling | Wang, Qing | Zhao, Wei

Article Type: Research Article

Abstract: Electromagnetic ultrasonic testing, based on the propagation characteristics of the ultrasonic wave in the medium, is an effective technique for defect detection. The structural of the electromagnetic acoustic transducer (EMAT) determines the detection effect, which should be reasonably designed. We propose an improved unilateral point-focusing EMAT structure with curved coils in this manuscript. The 3D model of the designed EMAT is numerically simulated utilizing the finite element method, and the bilateral point-focusing EMAT is also studied for comparison. The simulation results of the magnetic field intensity and the distributions of the displacement are shown in the manuscript, which prove the …effectiveness of the improved unilateral point-focusing EMAT. Five impact parameters such as aperture angle, focal position, excitation current, lift-off distance, and coil winding number are investigated in detail. We verify the calculation results of the aperture angle and excitation current by the experiments. The conclusion shows that the focusing intensity of the improved unilateral point-focusing EMAT is relatively higher, and other factors also have a significant effect on the focal intensity. Show more

Keywords: Point focusing, electromagnetic acoustic transducer (EMAT), unilateral, bilateral, numerical simulation

DOI: 10.3233/JAE-190071

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2019

Authors: Yang, Yiyi | Su, Sanqing | Wang, Wei | Ma, Xiaoping | Hu, Jingyu

Article Type: Research Article

Abstract: Metal magnetic memory (MMM) testing method has been proved to be a valid approach to monitor early damage and predict fatigue life, but there is no systematic description and comparison about the characteristics of MMM signals for welding and non-welding specimens with different materials under tension-compression fatigue. Thus, the fatigue tests for Q345B and Q345qC welding and non-welding specimens were carried out and the MMM testing was done synchronously. Then, based on the normal components of MMM signals, H p (y ), and its variations, ΔH p (y ), the slope of ΔH p (y ) fitting …curves, K C , and the average of ΔH p (y ) signals on the whole testing line, ΔH p (y )ave , were extracted as the characteristic parameters for Q345B and Q345qC non-welding specimens, respectively. Additionally, the gradient of “peak–vale” on H p (y ) signals curves, k , and the average of H p (y ) signals in the scope of welding zone, H p (y )ave , were extracted as the characteristic parameters for Q345B and Q345qC welding specimens, respectively. Some conclusions can be drawn by comparison: the variation laws of H p (y ) signals with cyclic loads are related to the material. The characteristic parameters for welding and non-welding specimens with the same material have a certain similarity. Then, the failure of non-welding steel can be warned early by K C or ΔH p (y )ave when the fatigue life has 20% left, but the damage degree of welding specimen should begin to be valued highly once the k or H p (y )ave is decreasing. Finally, the fatigue life of welding and non-welding specimens with different materials can be evaluated effectively by using corresponding magnetic characteristic parameters. Show more

Keywords: Metal magnetic memory (MMM) testing, fatigue life, magnetic characteristic parameter, Q345B and Q345qC steel, weldments

DOI: 10.3233/JAE-190064

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-25, 2019

Authors: Park, Eui-Jong | Jung, Sang-Yong | Kim, Yong-Jae

Article Type: Research Article

Abstract: The magnetic gears which can replace the mechanical gear system are actively studied recently. Improving the power density is growing importance because the characteristics that as gear ratio grows so power density decreases were observed. This paper analyzes the various characteristics (power density, efficiency, torque ripple, loss, and so on) according to the gear ratio in detail, and proposes a concept that high gear ratio by combining two low gear ratio. A target gear ratio is 10 to 1 and application is 1 kW wind turbine. To obtain the optimal combination, 30 gear ratios were considered, and initial design process was …shown about this concept to propose the direction of improving the power density. All models were analyzed with 2D-FEM by numerical analysis. Show more

Keywords: Finite element analysis, magnetic gears, power density, high gear ratio

DOI: 10.3233/JAE-190097

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2019

Authors: Toghraie, Davood

Article Type: Research Article

Abstract: Optimization of the cooling processes by fluids in many industries such as power generation, transportation, machining, and electronics is very important. Heat transfer equipment to achieve higher efficiency, need to downsizing of the equipment, and increase the heat transfer rate per unit of surface. The aim of this paper is to investigate the effect of MHD mixed convection flow of Cu-water nanofluid in a trapezoidal lid-driven cavity with different tilt angles in a range of 0° to 60°. The cavity consists of the non-uniformly heated bottom wall, insulated top wall, and isothermal sidewalls. The governing equations of the flow by …using the finite volume method and the SIMPLE algorithm have been numerically solved. The studies for the wide range of Richardson number (Ri) from 0.01 to 10, volume fraction of nanoparticles from 0.1% to 4% and Hartman number (Ha) from 0 to 40 in the steady-state have been done. Result in the form of streamline, vorticity and temperature contours for three geometry, local Nusselt number graphs for non-uniformly heated bottom surface and velocity profile on the vertical centerline of the cavity in different geometry have been investigated. The results show that the average Nusselt number on the non-uniformly heated bottom wall is dependent on dimensionless parameters and tilt angles. Also, applying a magnetic field, reduce the velocity profile changes, and using nanoparticles will cause increasing the Nusselt number. Show more

Keywords: Mixed convection, magneto-hydrodynamic, trapezoidal cavity, non-uniformly heated surface

DOI: 10.3233/JAE-190123

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-28, 2019

Authors: de Souza Lima, Diorge | Mahmud, Lucas S. | de Sousa, Antonio R. M. | da S. Fonseca, Wellington | Bezerra, Ubiratan Holanda | Bezerra, Fábio Vinícius V.

Article Type: Research Article

Abstract: Sympathetic inrush current phenomenon occurs when a transformer is switched on in a power network containing other transformers that are already energized. This interaction significantly changes duration and magnitude of transient magnetizing currents in the transformers involved and may lead to misoperation of these equipment. Therefore, in this paper it is presented the results of electromagnetic analysis due to sympathetic inrush and inrush current phenomenon among single-phase 50 MVA transformers in a power substation in the northern region of Brazil. For this purpose, the nine single-phase transformers installed at SE Guamá forming three three-phase banks, were modeled in the ATP software …to obtain the energization behavior. In this paper the electromagnetic analyzes are performed in steady state, so only the first peak is used. In this way, results of the electromagnetic behavior of transformers are presented and compared sympathetic inrush with inrush current. Show more

Keywords: Sympathetic inrush, transformers bank, MEF, ATP software

DOI: 10.3233/JAE-190041

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2019

Authors: Ahn, Dahoon | Kim, Hyunchang | Choi, Kyungwho | Choi, Young-Man | Lim, Jae-Yong

Article Type: Research Article

Abstract: Magnetic levitation is state-of-the-art technology to realize 6 degree of freedom motion stages. The major weakness of magnetic levitation technology is the small force of the actuators, since electromagnetic actuators usually have small force compared to other actuators. Moreover, they always have to be turned on in order to compensate for the weight of the stage. In this paper, voice coil motors, a kind of electromagnetic actuator, are designed for a magnetic levitation stage. Two different types of voice coil motors are mathematically modeled, analyzed and optimized to obtain high force. According to the optimized final designs, the voice coil …motors are manufactured and their performances are evaluated. The optimal design results are compared with the finite element simulations and the test results of the manufactured products. Both types of voice coil motors show high force. The results are quantified and compared. Through the design process and the evaluation of the voice coil motors, a practical design guideline for a voice coil motor is suggested. Show more

Keywords: Voice coil motor, optimal design, aspect ratio, force capacity

DOI: 10.3233/JAE-190029

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-24, 2019

Authors: Ju, Lufeng | Tao, Wenqiang | Wang, Qunjing | Li, Guoli | Zhou, Rui | Qiao, Yuanzhong

Article Type: Research Article

Abstract: A novel three-degree-of-freedom (3-DOF) spherical motor based on the principle of minimum magnetic reluctance is proposed in this paper. This paper firstly introduces the structure of the reluctance spherical motor and explains the principle of 3-DOF motion of the motor in detail. Then, an analytical model for reversible torque-angle characteristics is established to accurately describe a complex nonlinear system of the spherical motor model by using piecewise function nonlinear fitting method. Finally, the simulation results of torque-angle characteristics based on the nonlinear model are compared with those of the 3D finite element method (FEM), which verifies the feasibility of the …nonlinear modeling. Show more

Keywords: Spherical motor, 3-DOF, nonlinear modeling, torque-angle characteristics, FEM

DOI: 10.3233/JAE-190072

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2019

Authors: Audiffred, D.B.S. | Possamai, T.S. | Travassos, X.L. | Ida, N.

Article Type: Research Article

Abstract: Composite materials have diverse engineering applications including the automotive, energy and aerospace industries. In manufacturing aircraft structures, the material is expected to endure atmospheric discharges. The present paper aims to model some of the effects of lightning strikes on a composite materials modeled through numerical simulation. The simulation is based on the finite-difference time-domain method which allows analysis the electromagnetic and thermal effects related to the problem. Aerospace standards are taken into account for modeling a lightning strike on a composite plate. The thermal distribution is evaluated based on results obtained from an electromagnetic simulation of the lightning strike effect. …Since multiphysics problems are complex, the hypotheses adopted to obtain the results are also discussed. Results show the current density distribution on a carbon fiber reinforced plastic plate varying with the anisotropy characteristics of the material. From the thermal simulation it is shown that the lightning strike can cause a rise in the composite temperature over 900 °C with only 1 μs of interaction with the material. Show more

Keywords: Lightning strike, composites, numerical modeling, multiphysics modeling

DOI: 10.3233/JAE-190045

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2019

Authors: Su, Sanqing | Wei, Luxi | Wang, Wei | Yang, Yiyi | Ma, Xiaoping | Zuo, Fuliang

Article Type: Research Article

Abstract: Metal magnetic memory testing (MMMT) is a nondestructive testing technique that can detect early damage of component. In order to distinguish the effect of normal stress and shear stress on magnetic field, the flexural loading testing of inclined steel box girder with corrugated web is carried out by four-point bending pattern, and the normal component of the magnetic field at different position of the beam under different load level are collected. It is found that the law of normal component of the magnetic field changing with load is similar under different stress states, but the amplitude is quite different. The …stress in Jiles–Atherton model can be replaced by equivalent stress when calculating the magnetic field under shear stress. Show more

Keywords: Metal magnetic memory testing (MMMT), bridge steel Q345qC, four-point bending, shear stress, equivalent stress

DOI: 10.3233/JAE-190075

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2019

Authors: Yao, Xing-Yan | Pecht, Michael

Article Type: Research Article

Abstract: Magnetorheological (MR) damper is a smart device which the damping force can be adjusted according to the working operations in a short time. Metal foam MR damper is a new type of MR dampers in which uses the metal foam to store and release the MR fluids. The dynamic response time of the metal foam MR damper is quite different due to the added metal foam especially for the dynamic response time model. This paper proposed a dynamic response time model for the metal foam MR damper based on the demonstration of the working mechanisms and the factors about the …response behaviors. Show more

Keywords: Magnetorheological (MR) fluid, MR damper, metal foam, dynamic response time model

DOI: 10.3233/JAE-190063

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2019

Authors: Qiu, Hongbo | Zhang, Yong | Yang, Cunxiang | Yi, Ran

Article Type: Research Article

Abstract: The application of surface permanent magnet synchronous motor (SPMSM) driven by inverter is becoming more and more extensive. However, the voltage harmonics generated by the inverter will have a severe impact on the motor torque ripple. In order to analyze its impact, a 1500 r/min 3 kW SPMSM is taken as an example. Firstly, the two-dimensional finite element model is established, and the accuracy of the model is verified by the experiment. Secondly, the torque ripple is calculated and analyzed. The influences of voltage harmonic amplitude and voltage harmonic initial phase angle on torque ripple are mainly studied, and the variation law …is obtained. At the same time, in order to distinguish the influence of higher harmonics on torque ripple, the voltage harmonics is decoupled to get the variation law of torque ripple. Finally, based on the analysis of the current ripple and air gap magnetic density, the influence mechanism of voltage harmonics on torque ripple is revealed. The conclusion is helpful to optimize motor design and improve motor performance. Show more

Keywords: Air-gap flux density, finite element method, SPMSM, torque ripple, voltage harmonic

DOI: 10.3233/JAE-190010

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: He, Yunfeng | Zhan, Jiawen | Lu, Qinfen

Article Type: Research Article

Abstract: In order to fast calculate the thrust force and normal force of linear induction motor (LIM) for low-speed maglev train under overall conditions including traction and braking, this paper proposes an improved equivalent circuit (EC) method. Firstly, the improved equivalent circuit model is proposed based on the traditional one by adopting a precision correction factor, which can accurately consider the transverse edge effect of cap-shape secondary conducting sheet. Moreover, the permeability of back-iron and magnetic inductance are amended considering the saturation effect. The corresponding calculation procedure is given out. Then, the precise correction factor is investigated based on 2D finite …element (FE) model. By comparison with the traditional Russell and Norsworthy correction factor (RNF), the precision correction factor is proved to be more suitable to LIM with wide-range slip frequency. Finally, the thrust force and normal force of LIM with different slip frequency are predicted under braking and traction conditions by improved EC method. The predicted results and the proposed method are validated by 3D FE method and experiment results. Show more

Keywords: Braking condition, equivalent circuit (EC) method, linear induction motor (LIM), low-speed Maglev train, normal force, slip frequency, transverse edge effect

DOI: 10.3233/JAE-190053

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Hao, Yang | Heng, Liu | Fan, Yang | Zhenwei, Ji | Bing, Gao | Min, Gong | Boda, Zhou | Chenzhi, Zhu

Article Type: Research Article

Abstract: The special working condition of shore power cable is more likely to form a crack air gap in insulating medium, which will cause gap discharge. The continuous gap discharge will cause local temperature rising and stress concentrating, which will lead to cable insulation deterioration. The electro-thermal-stress coupling method, in this paper, is used to establish the finite element model of the shore power cable. The electric, temperature and stress field distribution for the shore power cable with a crack air gap in the insulating medium is also studied, and the correctness of temperature and stress field distribution is verified by …experiments. In addition, this paper investigated the variation law of the ampacity for shore power cable under different discharge energy. The results show that the maximum electric field is equal to the electric field intensity (36.1 kV/cm) at the inner edge of the insulating medium when the gap length d = 2 mm and that the temperature and stress of the cable are quadratic with load current, linear with the gap discharge energy. The research results of this paper have an engineering significance for monitoring shore power cables. Show more

Keywords: Shore power cable, multi-physics field, discharge energy, ampacity

DOI: 10.3233/JAE-190088

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2019

Authors: Xing, Jichun | Ren, Wendi | Qin, Yong

Article Type: Research Article

Abstract: For a non-contact piezoelectric motor modulated by an electromagnetic field, the design scheme of a piezoelectric micro-displacement amplifying mechanism is described. The relation formula between the output displacement of piezoelectric stacks and the output angle of the mechanism are given. Using the theory of electromagnetism, the static output torque equation of electromagnetic coupling mechanism based on the output angle of the piezoelectric amplifying mechanism is established, and the effect of system parameters on the static output moment is analyzed. Considering this piezoelectric motor driven by square wave signal, the dynamic output torque equation of the non-contact piezoelectric motor is established, …and the effect of system design parameters on the dynamic output torque is revealed. The analysis results show that the different output step precisions of the piezoelectric motor can be obtained by adjusting the length of the bar 1. A reasonably selected output angle is beneficial to increase electromagnetic torque. When the air gap is reduced to improve the torque, a larger output torque can be obtained by designing a reasonable output angle. At a certain amplitude of modulation voltage, the reasonable combination of external resistance and modulation signal frequency is beneficial to the design of an ideal dynamic torque response waveform and larger dynamic torque amplitude. The above analysis results can lay a theoretical foundation for the design of a high-performance non-contact piezoelectric motor modulated by electromagnetic and the optimization of the drive scheme. Show more

Keywords: Electromagnetic torque, non-contact, modulated by an electromagnetic field, flexure hinge mechanism

DOI: 10.3233/JAE-180116

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2019

Authors: Lin, Chih-Hong | Chang, Kuo-Tsai

Article Type: Research Article

Abstract: Compared with the classical linear controller, the nonlinear controller can result better control performance for the nonlinear uncertainties of the continuously variable transmission (CVT) system which is driven by the synchronous reluctance motor (SynRM). The better control performance can be shown in the nonlinear uncertainties behavior of CVT system by using the proposed novel admixed improved recurrent Hermite polynomial neural network (AIRHPNN) control system. The novel AIRRHPNN control system can carry out overlooker control, improved recurrent Hermite polynomial neural network control (IRHPNN) with an adaptive law, and reimbursed control with an appraised law. Additionally, according to the Lyapunov stability theorem, …the adaptive law in the IRHPNN and the appraised law of the eimbursed controller are established. Furthermore, two weights with two varied learning rates according to increment Lyapunov function are derived to help improving convergence. Finally, comparative examples are illustrated by the experimental results to confirm that the proposed control system could be obtained better control performance. Show more

Keywords: Continuously variable transmission, Lyapunov stability, recurrent Hermite polynomial neural network, synchronous reluctance motor

DOI: 10.3233/JAE-180079

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-28, 2019

Authors: Li, Xi | Zhang, Juwei | Shi, Jingzhuo

Article Type: Research Article

Abstract: In order to solve the problems including poor signal denoising effect, low recognition rate, and poor real-time performance in wire rope magnetic flux leakage (MFL) testing, this paper proposes a new algorithm combining kernel extreme learning machine (KELM) with compressed sensing wavelet (CSW). Firstly, we consider a new mechanism and regularized orthogonal matching pursuit (ROMP) into CSW, and combine double-density wavelet transform (DD-DWT) to improve the result of wire rope signal noise reduction; Then, an effective normalization method is developed to improve the accuracy of classification. Finally, the detection accuracy and efficiency in wire rope quantitative identification are ameliorated through …KELM. The effectiveness and novelties of the proposed algorithms are verified by the experimental platform based on unsaturated magnetic excitation non-destructive testing (NDT) device. Show more

Keywords: Wire rope, non-destructive testing, compressed sensing, kernel extreme learning machine, quantitative identification

DOI: 10.3233/JAE-190024

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2019

Authors: Wu, Jiamin | He, Yucheng | Shen, Sheng | Guo, Pan | Huang, Xin | Xu, Zheng

Article Type: Research Article

Abstract: Traditional nuclear magnetic instruments are not convenient for measurement in situ due to the closed magnet structure and heavy weight. It is crucial to improve tree planting by exactly detecting moisture parameters of living trees. To investigate this problem, an open and portable magnetic resonance sensor was proposed. In this work, we introduced unilateral magnetic resonance sensor which can achieve onsite nondestructive measurement of large-volume samples due to its open structure. To fit the shape of living trees, the region of interest was set in an arc region. A magnet structure was optimized by ANSYS software. Because the magnet has …a constant natural gradient along radial direction, we need gradient fields in the other two directions (Z and Y). Z/Y gradient coils for unilateral magnetic resonance sensor are studied based on the Fourier series method. Current density in gradient coils is assumed as Fourier series composed of trigonometric functions. We introduced stream function to establish relationship between the current density and the winding structure, then constructed an optimization model by combining power dissipation with the deviation between calculated field and target field. The coils are manufactured using a flexible printed circuit board and measured by gauss meter. The measurement and simulation results are consistent. Measurement results of the gradient coils showed that the magnetic fields have good linearity which is helpful to realize 3D measurement in the upcoming work. Show more

Keywords: Unilateral magnetic resonance, Fourier series method, gradient coil design

DOI: 10.3233/JAE-190076

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Liu, Bingcheng | Liu, Ning | Wang, Shaoyi | Jia, Wenguang

Article Type: Research Article

Abstract: Magnetic induction intensity and current are crucial factors to determine the effect of electromagnetic anti-fouling technology (EAFT). For getting the current value in the coil which was tightly wrapped around the PVC pipe, the inductance and equivalent resistance of the coil was measured by LCR meter, and the current in the circuit of the anti-fouling system was obtained by Ohm’s law. The magnetic induction intensity in the solenoid centre can be calculated by Faraday’s law. The purpose of the experiment was to find the optimal output parameters of EAFT and explored the anti-fouling effect. Therefore, we established an experimental platform …to optimize the output parameters and explore the effect of different output frequency on solution conductivity and particle diameter. Through experiments, it’s found that current in the coil was reduced with increasing frequency, the number of turns and the diameter. As the frequency and diameter increase, the magnetic induction intensity reduced, and the turns basically no impact on the magnetic induction intensity. The hardness solution of 10 mol ⋅ m−3 (as CaCO3 ) is treated by four different frequencies electromagnetic field shows that the lower the frequency, the greater decrease in conductivity and the greater increase in particle size, that phenomenon verifying that the higher current and stronger magnetic field intensity has a better anti-fouling effect. Show more

Keywords: Electromagnetic anti-fouling technology, current, magnetic induction, conductivity, particle diameter

DOI: 10.3233/JAE-190055

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Gong, Qi | Zhang, Weiwei | Su, Yufeng | Zhang, Kun

Article Type: Research Article

Abstract: In this paper, a diamagnetic-airflow hybrid levitation structure is reported, with a floating magnet rotor stably levitated above a diamagnetic disc just using a lifting magnet and airflow. Compared with the typical diamagnetically stabilized structure, the rotation speed of the rotor is increased from 9570 rpm to 16666 rpm, and the levitation gap is increased from 0.3 mm to 0.7 mm when the airflow rate exceeds 2198 sccm under standard temperature and pressure (STP). At the same time, the rotor can be stably levitated at any height from 0.2 mm to 0.8 mm by adjusting the vertical position of the nozzles. With the hybrid levitation structure, it’s …possible to overcome the structural limitation of typical diamagnetically stabilized levitation structure and enhance the working performance of the rotor. This levitation structure is expected to be applied to sensing, energy harvesting and air bearing under actuation of airflow. Show more

Keywords: Diamagnetic, airflow, stabilized levitation, simulation, energy harvesting

DOI: 10.3233/JAE-190081

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-14, 2019

Authors: Mingliang, Zheng

Article Type: Research Article

Abstract: In this paper, the Lie symmetry theory of singular mechanico-electrical coupling systems is studied in phase space. Firstly, the Hamilton canonical equation of singular mechanico-electrical coupling systems is established through energy; Secondly, considering the inherent constraints brought by singularity, the determining equations, definitions, structural equations and conserved quantities of Lie symmetry are all given; Finally, an application example is given. It is shown that if the structural equation of Lie symmetry is just right the criterion equation for Noether symmetry, then the Lie symmetry can lead to the conserved quantity of Noether type; if the structural equation of Lie symmetry …does not involve the Hamiltonian function, the conserved quantity of non-Noether type can be obtained only through finding the invariant of symmetric group. Show more

Keywords: Singular mechanico-electrical coupling systems, Lie symmetries, structural equations, conserved quantities

DOI: 10.3233/JAE-190059

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-9, 2019

Authors: Shi, Yan | Lin, Cong | Lu, Bin

Article Type: Research Article

Abstract: Electromagnetic linear actuator (EMLA) is an alternative of the conventional damper in vehicle suspensions and harvests suspensions vibration energy which is wasted generally. Due to large variations of its Back Electromotive Force (Back-EMF), it will thus be interest to investigate how to recycle the electricity efficiently. In this paper, to improve the recycling efficiency of the EMLA, a feedback energy circuit featured with combination of parallel switchover supercapacitors technology and a boost-buck DC-DC converter is proposed on the basis of the generating characteristics of a newly designed EMLA. By modeling the feedback energy circuit, its dynamic characteristics are simulated and …its efficiency is investigated. The results of simulations and experiments show that the feedback energy circuit can achieve a wide range of energy recovery regardless of large variations of Back-EMF induced by the EMLA. Simultaneously, by keeping the boost-buck ratio less than 3, the efficiency of energy recovery is high, in some cases could reach 94%. Show more

Keywords: Energy harvesting, electromagnetic linear actuator, active suspensions, feedback energy circuit

DOI: 10.3233/JAE-180135

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2019

Authors: Liu, Yafeng | Wang, Xinjie | Wang, Jiong | Chen, Hejuan

Article Type: Research Article

Abstract: The lanthanum-doped lead zirconate titannate (PLZT) ceramic has shown its potential applications as light-controlled micro actuators activated by ultraviolet light for the photovoltaic effect in the field of micro-driven. Aiming to the slow response of photostriction of PLZT ceramic, the primary purpose of this article is to propose a light-controlled actuator with the novel opto-electrostatic hybrid driving based on PLZT ceramic. The mathematical model of the proposed light-controlled actuator is established on basis of the anomalous photovoltaic effect model of PLZT ceramic. The actuation characteristics of the micro actuator are investigated based on the established mathematical model and the experiments …of the photovoltage of PLZT ceramic. Furthermore, the actuation curves of the micro actuator driven by opto-electrostatic hybrid driving based on PLZT ceramic are acquired to verify the rationality and feasibility of the light-controlled micro actuator design. So according to the analysis and experimental results, the light-controlled actuator driven by the novel opto-electrostatic hybrid driving based on PLZT can conduct the effectively and precisely displacement control with fast response speed. In addition, the driving method based on the novel opto-electrostatic hybrid driving has advantages of non-contact control, remote control and no electromagnetic interference, etc. Show more

Keywords: PLZT, micro actuator, opto-electrostatic hybrid driving, light-controlled

DOI: 10.3233/JAE-190035

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: Li, Zhao | Yan, Li | Qu, Boyang | Fu, Kai

Article Type: Research Article

Abstract: In this paper, an analytical model is proposed to predict the magnetic field and torque characteristics of flux-concentration cage-type eddy-current couplings with slotted conductor rotor topology. Due to the presence of discontinuous boundary conditions in permanent magnet rotor domain and conductor rotor domain, the accurate sub-domain method is employed in polar coordinates. The permanent magnet domain and the conductor domain are divided into different sub-domain according to the number of poles and slots. The magnetic vector potential in each domain is obtained by solving the field equation based on the separated variable method. Then the magnetic field distributions and output …torque are computed. By using the nonlinear 2D and 3D finite element analysis, the validity of such model is proved, and the cause of deviation is discussed. In the end, the proposed formula is used for a design optimization using particle swarm optimization algorithm. Show more

Keywords: Eddy-current couplings, sub-domain method, finite-element method, design optimization

DOI: 10.3233/JAE-190056

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2019

Authors: Zhang, Yuyang | Leng, Yonggang

Article Type: Research Article

Abstract: Magnets are widely used in many fields, both industry and our daily life, because of their unique properties such as non-contact interactions and electricity generation. However, behaviors of permanent magnets seem to deviate from our basic understanding that opposite poles attract and like poles repel. We have recently discovered an interesting phenomenon in pairs of permanent magnets with large different sizes where the like poles do not seem to repel and the unlike poles do not seem to attract with each other, due to a localized area with reversed pole existing in the large permanent magnet. In this paper, we …first experimentally confirm the existence of this particular phenomenon by studying interactions of several groups of permanent magnets with different sizes, then we introduce the property of the irreversible movements of load line and working point of permanent magnet to figure out this transition process from repulsion to attraction between a pair of permanent magnets with large different sizes. A reasonable explanation is finally given. In the end, we suggest a few applications for this special phenomenon. Show more

Keywords: Magnetic force calculation, load line, demagnetizing field, working point

DOI: 10.3233/JAE-190057

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2019

Authors: Wu, Jie | Hu, Hong | Liang, Jian

Article Type: Research Article

Abstract: This paper investigates the magnetic circuit model of a multi-pole multi-layer magnetorheological (MR) brake. Firstly, a simple introduction to the structure is given. This MR brake has a unique structure design with several MR fluid working gaps set between two-layer coils. Then, magnetic circuit model is conducted to theoretically approximate the effects of the design parameters on the magnetic field strength within the MR fluids. According to the magnetic circuit analysis, a parametric study is performed to optimize the critical design parameters of the magnetic circuit of the designed brake. Finally, the magnetic circuit model is validated based on the …optimized structure and simulation. Simulation results indicate that the magnetic circuit model is feasible to estimate the magnetic field strength in the working gaps, and it can be used to guide the parameters optimization and structure design. Show more

Keywords: Magnetorheological (MR) brake, magnetic circuit, modeling, finite element analysis, optimization

DOI: 10.3233/JAE-190025

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-24, 2019

Authors: Liu, Qing | Wang, Li | Zhang, Shiping | Wang, Xinjie | Yu, Chengyu | Lei, Gang

Article Type: Research Article

Abstract: Based on the non-contact characteristics, active magnetic bearings (AMBs) possess great benefits like no lubrication, high speed, high accuracy and long lifespan. Moreover, the rotor dynamic performance is adjustable and working conditions are monitorable. Nonetheless, AMBs suffer from large power loss and rotor heating. One viable approach is omitting the bias current, i.e., zero-bias AMBs, but this also results in high non-linearity and poor controllability. The common control practices of zero-bias AMBs are based on nonlinear models, for there is only one electromagnet being electrified at any moment to produce a net control force. Here, we propose a linear control …strategy for zero-bias AMB. Assuming that each coil has an average current proportional to the pulse width modulation (PWM) duty cycle, the quantitative relation among the magnetic force, the rotor displacement and the coil current can be acquired. Further, this control algorithm was applied to both the horizontal and the vertical thrust zero-bias AMBs. Experimental results proved the existence of currents in both electromagnetic bearings in the unbalanced state. And the rotor-bearing system restored rapidly to an equilibrium state after sudden disturbances. Overall, this method demonstrates the transition from physics to engineering and shows a good application prospect. Show more

Keywords: Zero-bias magnetic bearing, mathematical model, quantitative control, PWM, power consumption

DOI: 10.3233/JAE-180127

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-22, 2019

Authors: Huang, Lantao | Zou, Jiahao | Zhang, Jing | Zhou, Yihan | Deng, Fangxiong

Article Type: Research Article

Abstract: Eddy current testing is one of electromagnetic methods that are suitable for the inspection of conductive materials. Compared to regular flat coil, rectangular vertical coil can induce a more uniform eddy current distribution in the plate. With other advantages such as directional properties and less sensitive to lift-off variations, the rectangular vertical coil is considered superior to the flat one in certain applications. However, the eddy current of the conventional rectangular vertical coil is comparatively low as the weak coupling between the coil and the conducting plate. It is challenging to achieve high sensitivity and accuracy for the detective sensor …such as GMR or pickup coil. To increase the coupling, a novel probe with a conductive shell is proposed in this study. With the proposed probe, a conductive loop can be formed by the test plate and shell when the shell is in good contact with the test plate during the test. And the conductive loop can effectively increase the coupling and the induced current in the test plate. A simulation model is set up with the finite element method to verify the performance of the designed probe. The results show that the eddy current density in the plate is improved by the proposed probe. When a defect is present, the change of the magnetic flux density and equivalent reactance of the proposed probe are more obvious than the conventional rectangular vertical coil. This improvement is also validated by the experiment of equivalent reactance measurement. Show more

Keywords: eddy current, electromagnetic coupling, finite element analysis

DOI: 10.3233/JAE-190058

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2019

Authors: Xiong, Linghao | Sun, Zongxiao | Chen, Qingxiao | Xie, Tianyu

Article Type: Research Article

Abstract: Methods of position tracking based on magnetic field monitoring have been widely studied. The application of electromagnetic tracking (EMT) in endoscopic procedures not only has high requirements for position accuracy but also has a great demand for orientation accuracy. Accurate orientation information can provide more clues for shape fitting of the endoscope, especially when coils are placed at the front end of the endoscope for front end shape reconstruction. However, few methods have been proposed to calibrate position and orientation errors at the same time, while most methods are focused on position error correction. This paper presents a new method …showing that by separating the tracking space into grids and calibrating the grid-sensing coil position and orientation parameters (GSCPOP), the position and orientation accuracy can be improved simultaneously by means of iterative computation. Compared to the uncalibrated method, position accuracy showed a 285% improvement, and orientation accuracy showed a 129% improvement. Show more

Keywords: Endoscope, EMT, GSCPOP, calibration method

DOI: 10.3233/JAE-190012

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Weichao, Dong | Lei, Du | Xin, Wang | Zheng, Li | Hexu, Sun

Article Type: Research Article

Abstract: To improve the utilization of wind energy, a new type of deflectable double-stators switched reluctance wind power generator is proposed to solve the unicity of the rotor rotation of existing switched reluctance generator (SRG). The generator adopts inner and outer double-stators structure. The multi-degree-of-freedom deflection of the rotating shaft can adapt to different wind directions and is suitable for the combination of electric fields with unstable energy amplitude, which can improve the working efficiency of the generator. The finite element analysis is used to calculate the rotation of the air gap magnetic flux inside the generator rotor, which lays a …foundation for analyzing the vibration displacement of the stator structure. The magnetostriction of stator structure is the main cause of generator vibration. Based on the theory of mechanics, the basic equation of structural mechanics considering magnetostrictive effect is established. Magnetio-solid coupling simulation of internal and external stator and rotor rotation and deflection is carried out using FEA, and the stress distribution and corresponding vibration displacement are obtained. The simulation and analysis results provide a reference for further optimizing the structure of such generators and improving the stability of their operation. Show more

Keywords: Magnetic solid coupling, structural mechanics, vibration displacement, double-stators, magnetostrictive effect

DOI: 10.3233/JAE-190027

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2019

Authors: Li, Ke | Ling, Feng | Sun, Xiaodong | Zhao, Dean | Yang, Zebin

Article Type: Research Article

Abstract: The reactive power-based model reference adaptive controller (MRAC) is presented in this paper in detail to estimate rotor resistance online. This controller can maintain rotor flux orientation of bearingless induction motor (BIM) driven by indirect vector control. The instantaneous and steady state reactive power of the rotating part of the BIM are selected in the MRAC as reference model and adjustable model, which automatically protects the entire system from any effects of stator resistance. In addition, this proposed formation of MRAC is independent of the requirement for the estimation of any flux in the calculation process. Therefore, this scheme is …not influenced by the integration, and the problems like saturation and drift can be ignored. At zero speed, this scheme will estimate the rotor resistance more accurately. A speed sensorless scheme can be proposed after adding flux estimators to the MRAC. The effectiveness of the proposed scheme has been verified in MATLAB/SIMULINK. Show more

Keywords: bearingless induction motor, model reference adaptive controller, reactive power, estimation, sensorless

DOI: 10.3233/JAE-190042

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2019

Authors: Ren, Xiaojun | Feng, Ming | Chen, Shaohua | Miao, Cunxiao | Ren, Yuan

Article Type: Research Article

Abstract: Different from separated magnetic bearing units, combined radial-axial magnetic bearing (CRAMB) has cross coupling problem caused by structure itself. This paper focuses on the study of cross coupling problem for a CRAMB caused by structure itself. An equivalent magnetic circuit model (EMCM) considering the leakage and coupling effects was presented to analyze the mechanism of cross coupling. The analysis results show that due to the influence of magnetic flux leakage and common bias magnetic circuit, cross coupling between axial and radial direction caused by the structure itself of a CRAMB cannot be ignored. The coupling degrees of factors that cause …cross coupling are analyzed based on the combination of EMCM and finite element method (FEM). The analysis results show that the coupling effect caused by axial magnetic flux leakage was most serious. To solve the coupling problem caused by the structure itself, the coupled transfer function is derived. This coupled transfer function has been added in the original controller. Experimental results show that the cross coupling effect was reduced effectively and CRAMB can levitate the rotor at 48000 r/min stably with the improved controller. Show more

Keywords: Cross coupling, combined radial-axial magnetic bearing, decoupling design, magnetic flux leakage

DOI: 10.3233/JAE-190013

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2019

Authors: Zhai, Fangfang | Liu, Guohai | Xu, Gaohong | Chen, Qian

Article Type: Research Article

Abstract: This paper presents a torque performance improvement method for three-phase consequent-pole permanent magnet (PM) (CPM) machines. The key of this method is to consider torque ripple and output torque simultaneously in CPM machines. This method is realized by adopting optimized six-layer winding and Halbach PMs array. The optimized six-layer winding is employed to reduce the torque ripple by suppressing the even-order harmonics in phase back electromotive forces (back-EMFs). The principles of both even-order harmonics in phase back-EMFs and torque ripple suppression by the optimized six-layer winding are illustrated. There will be a slight reduction of main harmonic back-EMF due to …multilayer winding, then resulting in slightly lower torque production. Hence, the Halbach PMs array are adopted to compensate the output torque. Therefore, the proposed CPM machine has similar output torque with the conventional CPM machine. However, the torque ripple of the proposed CPM is much lower than conventional CPM machine. Meanwhile, the PM utilization ratio can be increased more than 37% compared with the conventional SPM machine. Finally, the theoretical analyses are verified by the finite-element method. Show more

Keywords: consequent-pole, Halbach PMs array, optimized six-layer winding, PM utilization ratio, torque ripple reduction

DOI: 10.3233/JAE-190007

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2019

Authors: Li, Yanbin | Qu, Boyang | Zhu, Yongsheng | Wan, Yaning | Zhu, Xingheng

Article Type: Research Article

Abstract: With the great concerns on alleviating the environment pollution and traffic congestions, there is a trend for developing light electrical vehicles in urban areas. This paper proposes an outer rotor flux switching permanent magnet machine (FSPMM) for light electric vehicle drive systems. The topology, operational principle and performance of the proposed machine are introduced. Then the procedure for choosing suitable combinations of stator slots and rotor poles is presented by using the sizing equation and finite element method (FEM). It is found that the optimal combination is 6 stator slots and 19 rotor poles for this application. Finally, a 188 W …120 rpm outer rotor FSPMM of the optimal stator/rotor combination is designed and analyzed. The magnetic field distribution and machine parameters are calculated by using FEM, and the performance is predicted based on the current vector control strategy. Show more

Keywords: Flux switching permanent magnet machine (FSPMM), light electrical vehicle, flux weakening ability, finite element method (FEM)

DOI: 10.3233/JAE-190079

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: Liu, Jinhui | Meng, Dawei | Ai, Mengmeng

Article Type: Research Article

Abstract: In order to improve the reliability of high-voltage motor core, the deteriorated performance parameters of core structure under deteriorating condition are needed. However, the current research on performance reliability mainly focuses on entire motor system, the performance deterioration analysis and fault simulation of the local core structure have not been studied extensively. At the same time, based on the contradiction between calculation ability and accuracy, the calculation of laminated core modeling is large and time-consuming. In this paper, a reliability analysis method of core performance based on multi-scale method and eddy current testing method is proposed. Firstly, the equivalent circuit …network is established according to the multi-scale structure of the core to simulate the performance deterioration process of the core. Then, the deterioration parameters are determined according to the analysis of insulation deterioration, and the three-dimensional eddy current field model and analysis of the core during insulation deterioration are carried out. Finally, the core sensor is designed based on eddy current testing method, and the performance deterioration experiment of the prototype is carried out, and the simulation data and experimental data are compared, the results show that the error between simulation parameters and experimental data is less than 5%, which verifies the validity of the performance reliability analysis method. Show more

Keywords: Eddy current testing method, insulation deterioration, multiscale method, performance deterioration

DOI: 10.3233/JAE-180119

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2019

Authors: Lin, Ling | Deng, Renjie | Hu, Yanbin | Shan, Hongxuan | Hu, Shunan | Jiao, Hongyu

Article Type: Research Article

Abstract: The two-dimensional viscous space-time conservation element and solution element (CE/SE) method is used to calculate the multi-phase detonation of plasma jet ignition. The effects of viscosity on the detonation flow field are compared with the N–S equation and the Euler equation as the governing equtions, and the effects of the jet temperature, time and initial droplet radius on the deflagration-to-detonation transition are analysed. The results show that the effect of viscosity on the propagation of detonation waves is very small, but the viscosity has certain effects on the detonation parameters. It is possible to significantly shorten the (deflagration-to-detonation transition) DDT …distance of the stable detonation by increasing the temperature and time of the initial jet ignition. When the plasma jet has already fully ignited the detonable mixture, increasing the jet time has little effect on shortening the DDT distance. When the droplet radius is less than 50 μm, the peak pressure of the detonation wave increases with an increase in the droplet radius, and the peak pressure decreases with an increase in the droplet radius when the droplet radius is more than 50 μm. Show more

Keywords: pulse detonation engine, plasma jet, deflagration to detonation transition

DOI: 10.3233/JAE-190046

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Li, Zechen | Bao, Xiaohua | Ni, Youyuan | Cheng, Shuai | Liu, Jiwei

Article Type: Research Article

Abstract: Although star-delta winding can improve the efficiency of motors because of a higher fundamental winding coefficient and lower harmonic winding coefficient. The requirement of turns ratio is very strict. If the turns ratio is not ideal, the core loss of the motor cannot be reduced, thus the efficiency will not be improved. In this paper, a design method for converting a star-delta winding of stator in small- and medium-sized motor into the concentric single-double layer star-delta (CSDLSD) winding is introduced and compared with a traditional delta winding and a star-delta winding. Besides, a method is provided to calculate the winding …coefficients of the motors with CSDLSD winding according to the turns number per slot. Harmonic component of magnetic flux density in stator tooth and yoke is consequently reduced, combined with partial core loss calculation method, the core loss is decreased. In addition, the core loss in three-phase induction machines equipped with front three winding types is also been estimated and analyzed. To check the analysis validity, two-dimension (2-D) Finite element method (FEM) is applied on three cage induction motors equipped with different winding types but the same prototypes. Show more

Keywords: Induction machine, CSDLSD winding, winding coefficient, core loss, finite element method

DOI: 10.3233/JAE-190003

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2019

Authors: Xu, Junqi | Chen, Chen | Sun, Yougang | Rong, Lijun | Lin, Guobin

Article Type: Research Article

Abstract: In this paper, the levitation system of low speed maglev vehicle is taken as the research object, and the suspension principle and adaptive control of the maglev system are discussed. The maglev vehicle is suspended by a combination of multiple electromagnet coils. Therefore, the coupling effect and parameter perturbation can not be considered based on single point levitation. This problem can be solved by building the characteristic model, and the effect of coupling between the electromagnet coils on the suspension performance can be fully considered. Therefore, in order to satisfy the control accuracy of magnetic levitation system, the identification and …adaptive problem of the levitation system of the maglev vehicle are studied according to the characteristic modeling theory. Specifically, the general dynamics model of maglev system should be established and improved. The model is transformed into a characteristic model with suspended clearance as control objective. Then, based on the least-squares method with forgetting factor, the coefficient of characteristic model is identified, and the estimation range of each coefficient is calculated. Finally, numerical simulation and experiment are carried out to verify the control effect. The results show that when the general adaptive control method is used to control the model, the characteristic model can better express the coupling effect between the electromagnet coils. It can express the environment variables and parameter interference more effectively. It is convenient to describe the influence of the coupling between the electromagnet coils in the suspension process, and provide a more effective model basis for further improving the control performance. Show more

Keywords: Maglev vehicle, parameter identification, coupling effect, characteristic modeling, adaptive control

DOI: 10.3233/JAE-190005

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-20, 2019

Authors: Liu, Zenghua | Li, Aili | Bin, Wu | He, Cunfu

Article Type: Research Article

Abstract: Electromagnetic acoustic transducers (EMATs) have been widely applied in non-destructive tests for structural health monitoring. This paper proposes a flexible surface wave electromagnetic acoustic transducer (FSW-EMAT), which uses flexible rubber magnets instead of hard permanent magnets, in order to achieve the defects detection of steel pipe or other ferromagnetic structures with a certain surface curvature. Traditional EMATs mainly consist of three parts: magnet, coil and metal specimen to be tested. Permanent magnets or electromagnets are generally used to produce the strong magnetic flux density. However, the two kinds of magnets are not suitable for the defect detection of metal specimens …with a certain curvature. The proposed FSW-EMAT in this paper adopts a flexible magnet, which is a mixture of rubber and iron powder and has strong flexibility to fit the bent specimen. The proposed FSW-EMAT can be easily applied in the testing of curved structural component and detect axial and circumferential defects by rotating the transducer. Show more

Keywords: Nondestructive testing, electromagnetic acoustic transducer, surface wave, pipe detection

DOI: 10.3233/JAE-190043

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2019

Authors: Chen, Wei | Wu, Guichu | Li, Yan | Ma, Jien

Article Type: Research Article

Abstract: This paper proposes a coupled finite element analysis of magnetic-thermal fields using an adaptive single-mesh method. To avoid errors from the data transfer and the mesh reconstruction due to different mesh requirements for the magnetic and thermal analysis, this proposed method built single mesh for both analyses. The results of the coupled parameters were transmitted through the single mesh between magnetic and thermal fields. According to the characteristics of the magnetic and the thermal distribution, the master-slave node method was employed to simplify the original element matrix into the magnetic and the thermal matrices, where slave nodes were no longer …solved in the solving process. Results of the slave nodes were expressed by their mater nodes using weight coefficients to regain the results of the original element matrix. A permanent magnet machine was introduced to validate the proposed method with both the commercial software and the experimental tests. Compared to the commercial software, the time cost was reduced by more than 8.0% when a higher accuracy of the thermal analysis was obtained. Show more

Keywords: Coupled analysis, finite element analysis, master-slave method, single mesh, thermal analysis

DOI: 10.3233/JAE-180093

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-14, 2019

Authors: Wang, Huimin | Wang, Tong | Zhang, Xuefeng | Guo, Liyan

Article Type: Research Article

Abstract: As the traditional flux-weakening control strategies have some limitations, such as poor parameter robustness, non-ideal dynamic performance in the constant power region and so on, a new control strategy based on the formula-based feedforward control and the voltage feedback control is proposed. In this strategy, the given reference values of the flux-weakening currents are first calculated by the simplified formulas used in feedforward control, improving the processing speed of the controller by reducing the computational complexity. Then the reference value of the d axis current is compensated by the fuzzy-PI feedback controller, avoiding operating point drifts caused by the …change or inaccurate of parameters in the actual. On this basis, a switching strategy is proposed to achieve a smooth switching between the constant torque and the constant power operation region. The experimental results show that the proposed control strategy has excellent performances, such as strong robustness to parameter perturbation, ideal dynamic performance in the flux-weakening region, smooth switching between the operation regions and so on. Show more

Keywords: Interior Permanent Magnet Synchronous Motor (IPMSM), flux-weakening, fuzzy-PI controller

DOI: 10.3233/JAE-190014

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Yin, Rui | Shi, Yan | Di, Changan

Article Type: Research Article

Abstract: Aiming at the problems of complex structure and slow response of the existing hydraulic active suspension actuator, an electromagnetic linear actuator (EMLA) with simple structure, stable operation is designed in this paper. Based on completing the structural design of the EMLA, the two-dimensional finite element model is established by using the finite element software JMAG, and transient analysis of EMLA is carried out, including analyses of no-load magnetic field and thrust force characteristics. The prototype is trial-produced, and its thrust force characteristics are measured on a designed test bench. The experimental values are close to the simulated values, which verifies …the correctness of the model. Finally, by analyzing the variation of the electromagnetic thrust force under different loading currents, this paper obtains the thrust force constant of the EMLA (183N/A). Show more

Keywords: Electromagnetic linear actuator, JMAG finite element, prototype, thrust force characteristics

DOI: 10.3233/JAE-190070

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: Zhang, Haijun | Zhang, Hua | Ma, Qiang | Han, Haifeng | Wang, Shuhong

Article Type: Research Article

Abstract: Frequency Response Analysis (FRA) is an effective diagnosis approach to detect the winding mechanical faults in power transformer. For understanding the FRA signatures of transformer windings quantitatively, this paper uses the sensitivity method to study the characteristics of frequency response function (FRF) in equivalent circuit of transformer windings. The sensitivity expressions of FRF can be determined by adjoint network method and Tellegen theorem, which reflects the influence of electric parameter changes on FRA signature under winding faults and within a wide-frequency band (10 Hz to 2 MHz). To verify the sensitivity calculation, a two-winding transformer model with seven discs was established and …taken as an example. The results indicate that FRF sensitivity data can provide the valuable insights about how the frequency responses are affected quantitatively with respect to the electric parameter changes or different winding faults. The method and sensitivity analysis discussed in this paper may be useful for diagnosing and predicting different mechanical deformation faults of transformer windings. Show more

Keywords: Transformer winding, equivalent circuit, frequency response, sensitivity analysis

DOI: 10.3233/JAE-190038

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2019

Authors: Ding, Li | Zhang, Jiasheng | Lin, Aiguo

Article Type: Research Article

Abstract: In order to ensure the safety of fluid flow in deep-water submarine pipelines, a safe and energy-saving built-in skin effect electric heat tracing technology was adopted as the thermal management strategy. By analyzing the multi-physics conditions of the electromagnetic field-temperature field in the heating state of pipelines, the corresponding control equations were derived, and the physical model was established using the transient electromagnetic-temperature coupling field of Ansys Workbench. Simultaneously, we calculated the equivalent parameters of the oil pipeline and heating cable as the load when the system is heated to different temperatures. Thus, the main circuit parameters of the power …supply for the built-in skin effect electric tracing system were designed, thus providing the theoretical guidance for the key performance optimization. For regulating the output power of the built-in skin effect electric heat tracing system, the nonlinear active disturbance rejection control strategy was newly adopted to achieve closed-loop power regulation based on the Buck chopper, and the system has the advantages of fast dynamic response and strong anti-interference ability. Finally, the feasibility of the proposed control system was verified by simulation. Show more

Keywords: Built-in, electric heat tracing system, coupled field, finite element analysis, ADRC

DOI: 10.3233/JAE-190001

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2019

Authors: Kim, Hong-Kyo | Kang, Beom-Soo | Kim, Jeong

Article Type: Research Article

Abstract: An electromagnetic launcher or accelerator is a useful device for obtaining a wide range of payload velocities. Electromagnetic launchers have smaller space requirements compared to compressed air gas launchers and can use easily obtainable grid electricity to provide thrust in place of a conventional propellant. Despite these advantages, it is difficult to measure launcher muzzle velocity, as the flames and light produced by the muzzle during launch make velocity measurement using a light sensor or high-speed camera impossible. To overcome this problem, B-dot probes can be used to track the projectile position within the launcher by sensing changes in the …magnetic field, which generate an induced voltage in the probe following Faraday’s law. This paper proposes a B-dot probe based method for measuring an electromagnetic launcher’s muzzle velocity. After determining the sensing effect as the probe positions and orientations through numerical simulation, the B-dot probe was used to measure the muzzle velocity, which was compared to a muzzle velocity obtained using a high-speed camera to validate the proposed method. Show more

Keywords: Electromagnetic launching, voltage measurement, velocity measurement, numerical analysis

DOI: 10.3233/JAE-190040

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2019

Authors: Meng, Fanxu | Zhou, Jin

Article Type: Research Article

Abstract: In this paper, a novel mechanical model based on arc tangent function is established to accurately describe the hysteretic behavior of the squeeze mode Magnetorheological (MR) damper. An improved differential evolution (DE) algorithm, which can avoid the shortage of being easily trapped in a local extremum, is applied to identify the parameters of the model. The dynamical characteristic of the MR damper is experimentally investigated with the help of the MTS machine. The validity of the proposed model is confirmed from a good agreement between the simulations and measured data. In addition, comparative analysis of the simulations with two other …existing models, reveals that the proposed model has a relatively high modelling accuracy with less parameters and explicit physical meaning. Show more

Keywords: Magnetorheological damper, squeeze-mode, characteristic analysis, modeling, differential evolution algorithm

DOI: 10.3233/JAE-190008

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2019

Authors: Yu, Xudong | Xie, Yuanping | Xiong, Zhenyu | Liu, Chang

Article Type: Research Article

Abstract: A ring laser gyroscope is an optical sensor based on the Sagnac effect. It has many outstanding advantages, such as a short start-up time, a high precision, a wide dynamic range and a stable scale factor. It is insensitive to accelerations and is in wide use in aircraft attitude control, north finding applications including navigation and space missions. The path length transducer in a ring laser gyroscope is required to stabilize the optical path of the laser beams in the cavity. The path length control transducer may tilt in complex environment, which will cause deformation of resonant optical path in …resonant cavity and seriously influence the performance of ring laser gyroscope. Firstly, for the first time, finite element analysis software ANSYS was used to simulate and analyze the small deformation of ring laser gyroscope’s grooved mirror in three directions under typical random vibrational spectra, their value were 2.08" , 2.10" and 1.30" respectively, and the deformation in the diaphragm of resonant cavity was obtained by combining with matrix optical theory quantitatively. Secondly, the influence rule of different radius of curvature and isostructural parameters on the tilt of path length control transducer was sought through quantitative analysis. Finally, combining with the change law of axial displacement in literature [5 ], an evaluation criterion for optimization was given and the optimized parameters were listed for path length control transducer. The tilt was reduced to 0.33" after optimization, which was about 21.4% of current structure. The axial displacement reached 3.89 um, which was 1.84 times of existing structure. The research in the paper could provide reference for the design of path length control transducer of ring laser gyroscope. Show more

Keywords: Ring laser gyroscope, path length control transducer, vibration, finite element analysis

DOI: 10.3233/JAE-190030

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2019