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

Authors: Ouaf, Mahmoud E. | Abou-zeid, Mohamed Y.

Article Type: Review Article

Abstract: The purpose of this paper is to investogate the ectromagnetic and micropolar properties on biviscosity fluid flow with heat and mass transfer through a non-Darcy porous medium. Morever, The heat source, viscous dissipation, thermal diffusion and chemical reaction are taken into consideration. The system of non linear equations which govern the motion is transformed into ordinary differential equations by using a suitable similarity transformations. These equations are solved by making use of Rung–Kutta–Merson method in a shooting and matching technique. The numerical solutions of the velocity, microtation velocity, temperature and concentration are obtained as a functions of the physical parameters …of the problem. Moreover the effects of these parameters on these solutions are discussed numerically and depicted graphically. It is found that the microtation velocity increases or deceases as the electric parameter, Hartman parameter and the microrotation parameter increase. Morever, the temperature increases as Forschheimer number, Eckert number increase. Show more

Keywords: Micro-polar fluid, heat and mass transfer, electromagnetic flow, non-Darcy porous medium

DOI: 10.3233/JAE-201623

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2021

Authors: Yu-dong, Xu | Cong, Li | Qiong-ying, Lv | Xin-ming, Zhang | Guo-zhen, Mu

Article Type: Research Article

Abstract: In order to study the effect of the trailing edge sweep angle of the centrifugal impeller on the aerodynamic performance of the centrifugal compressor, 6 groups of centrifugal impellers with different bending angles and 5 groups of different inclination angles were designed to achieve different impeller blade trailing edge angle. The computational fluid dynamics (CFD) method was used to simulate and analyze the flow field of centrifugal compressors with different blade shapes under design conditions. The research results show that for transonic micro centrifugal compressors, changing the blade trailing edge sweep angle can improve the compressor’s isentropic efficiency and pressure …ratio. The pressure ratio of the compressor shows a trend of increasing first and then decreasing with the increase of the blade bending angle. When the blade bending angle is 45°, the pressure ratio of the centrifugal compressor reaches a maximum of 1.69, and the isentropic efficiency is 67.3%. But changing the inclination angle of the blade trailing edge has little effect on the isentropic efficiency and pressure ratio. The sweep angle of blade trailing edge is an effective method to improve its isentropic efficiency and pressure ratio. This analysis method provides a reference for the rational selection of the blade trailing edge angle, and provides a reference for the design of micro centrifugal compressors under high Reynolds numbers. Show more

Keywords: Centrifugal compressor, bending angle, inclination angle, pressure ratio, isentropic efficiency

DOI: 10.3233/JAE-201590

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2021

Authors: El-dabe, Nabil T. | Abou-zeid, Mohamed Y. | Mohamed, Mona A. | Maged, Mohamed

Article Type: Research Article

Abstract: In this work, we focused on the peristaltic unsteady flow of non-Newtonian nanofluid with heat transfer through a non-uniform vertical duct. The flow obeys Herschel Bulkley model through a non-Darcy porous medium under the effects of mixed convection and thermal diffusion. Moreover, the effects of thermal radiation, heat generation, Ohmic dissipation, chemical reaction and uniform external magnetic field are investigated. The derived equations that describe the velocity, temperature and nanoparticles concentration are simplified under the assumptions of long wave length and low Reynolds number. These equations have been solved by using a numerical technique with the help of shooting method. …The obtained solutions are functions of the physical parameters entering the problem. The effects of these parameters and the obtained solutions are explained and discussed through a set of graphs. It is found that the increment in Prandtl number or Thermophoresis parameter reduces the spread of the nanoparticles (concentration increased) within the fluid along with the thermal diffusivity through the fluid layers. Also the non-Darcy effect supports the inertial forces, and in order to maintain Reynolds number, the viscous forces are motivated and the axial velocity is damped. Moreover, for the validation of the current methodology, this model is reduced to power law model (no yield stress) and compared with the work of Eldabe et al. [16 ]. Show more

Keywords: Peristaltic flow, Herschel Bulkley model, nanofluid, thermal diffusion, mixed convection, chemical reaction

DOI: 10.3233/JAE-201600

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2021

Authors: Maharani, Elliza Tri | Ubaidillah, U. | Imaduddin, Fitrian | Wibowo, K.M. | Utami, Dewi | Mazlan, Saiful Amri

Article Type: Research Article

Abstract: An experimental study was undertaken to evaluate the mathematical modelling of the magnetorheological (MR) damper featuring annular radial gap on its valve. The experiment was conducted using a fatigue dynamic test machine under particular excitation frequency and amplitude to get force-velocity and force-displament characteristics. Meanwhile, the mathematical modelling was done using quasi-steady modelling approach. Simulation using adaptive neuro fuzzy inference (ANFIS) Algorithm (Gaussian and Generalized Bell) were also carried out to portray the damping force-displacement modelling that is used to compare with the experimental results. The experimental characteristics show that amplitudes excitation and current input affect the result damping force …value. The comparison of the experimental and mathematical results presented in this paper shows a significant difference in damping force value and that the quasi-steady modelling could not significantly approach the damping force-velocity results. Moreover, the semi-active damper is compared to the passive damper. The results show that a semi-active damper performs better than a passive damper because it only requires a little power. Based on the damping force-displacement modelling, it can be seen that Gaussian has a higher accuracy rather than Generalized Bell. Discussion on the energy dissipation and equivalent damping coefficient were also accomodated in this paper. Having completed in mathematical modelling and simulation, the damper would be ready for further work in-vehicle application that is development of control system. Show more

Keywords: MR damper, annular-radial MR valve, quasi-steady modelling, MR damper characteristics, energy dissipated, ANFIS Algorithm

DOI: 10.3233/JAE-201560

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2021

Authors: Fan, Chen | Chongfeng, Zhang | Xiaolong, Yang

Article Type: Research Article

Abstract: In order to solve the problem of short service life (2 months) and zero leakage of air cylinder in aerospace engineering, this paper innovatively designs a magnetic fluid sealing device of air cylinder in aerospace engineering through magnetic circuit analysis and magnetic fluid sealing theory. The magnetic field finite element method is used to calculate the magnetic field distribution in the sealing gap under different key parameters such as the number of pole teeth, the height of the radial sealing gap, the thickness of the permanent magnet, the slot width, the ratio of pole piece height to shaft. And numerical …analysis of the number of pole teeth, the radial sealing gap height, permanent magnet thickness, slot width, the ratio of pole piece height to shaft and other key parameters on the magnetic fluid sealing performance. Finally, the reliability of the reciprocating magnetic fluid sealing withstand voltage is verified by experimental methods. Research indicates. The pressure capabilities of magnetic fluid sealing is increasing with the increase of the number of pole teeth. The pressure capabilities of magnetic fluid sealing is decreasing with the increase of the radial sealing gap. The sealing withstand voltage increases first and then decreases with the increase of the thickness of the permanent magnet, and finally increases, and the value of the withstand voltage is the largest when the thickness of the permanent magnet is 7.8 mm. The sealing pressure capabilities increases as the slot width increases. The sealing withstand voltage increases first and then decreases as the ratio of pole piece height to shaft increases, and when the ratio of pole piece height to shaft is 0.8, the sealing withstand voltage reaches a maximum value. The pressure test finally reaches the pressure value of 6 MPa, which can meet the pressure value demand of medium pressure cylinder, indicating that the magnetic fluid sealing technology can effectively solve the leakage problem existing in the air cylinder technology of Aerospace Engineering, and improve the reliability and service life of the air cylinder. Show more

Keywords: Aerospace engineering, air cylinder, magnetic fluid sealing, numerical analysis, key parameters, experiment

DOI: 10.3233/JAE-201572

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2021

Authors: Zhang, Jin | Wang, Xin | Wang, Xuebing | Zheng, LingLing | Li, Ruipeng | Lu, Chao | Shi, Wenze

Article Type: Research Article

Abstract: Due to the poor conversion efficiency and signal-to-noise ratio (SNR) of Electromagnetic Acoustic Transducer (EMAT) testing, the defect detection sensitivity is limited, which restricts the extensive industrial applications. A finite element model for the testing process of a meander-coil EMAT was established that considers the simplified excitation and detection circuits for the EMAT. Based on this model, the effect of the connection methods (parallel or series) of the coils in the generating and receiving EMATs on their generating and receiving efficiency was investigated, and the simulation results were validated experimentally. Subsequently, the pulse compression technique with a 13-bit Barker code …was used for the EMAT detection, and improvements of the SNR and range resolution were established through numerical simulation and experimental measurement. The results show that compared with the traditional EMAT design, which comprises single-layer transmitting and receiving coils, the conversion efficiency of the optimized EMAT with two excitation and receiving coils in the parallel connection can be improved by 52.8%. With the application of the Barker-coded pulse compression to detect the ultrasonic A-scan signal with no synchronous average, the SNR of the defect echo can be improved by 9.5 dB compared with the A-scan signal with 128 synchronous averages. Show more

Keywords: EMAT, surface wave, conversion efficiency, pulse compression, Barker code

DOI: 10.3233/JAE-201609

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-23, 2021

Authors: Cao, Junhao | Sun, Xiaodong | Tian, Xiang

Article Type: Research Article

Abstract: This paper focus on a state feedback controller (SFC)-based optimal control scheme for surface-mounted permanent-magnet synchronous motor (SPMSM) with auto-tuning of controller built on seeker optimization algorithm (SOA). First, based on the nonlinear state-space model of SPMSM, voltage feedforward compensation is used to design a linear SFC. Then in order to guarantee the steady performance in speed and current, integral models considering the errors of rotor speed and current response in d -axis are added in the state space model of SPMSM. Furthermore, by statically decoupling the load torque in the state equation, feedforward compensation is implemented on the load …torque to improve the dynamic performance of the controller. The load torque is estimated using disturbance observer with reasonable parameter selection. Then, with the consideration of the search capacity of seeker optimization algorithm (SOA), it is adopted to acquire matrix coefficient of the presented controller. Furthermore, in order to suppress the speed overshoot, a penalty term is introduced to the fitness index. The performance of the proposed method has been validated experimentally and compared with the conventional method under different conditions. Show more

Keywords: Surface-mounted permanent magnet synchronous motor (SPMSM), feedforward compensation, state feedback control, disturbance observer, seeker optimization algorithm (SOA)

DOI: 10.3233/JAE-201630

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2021

Authors: Sun, Hui | Zhao, Zhangyan | Wang, Gongxian | Zhu, Chao | Yu, Binbin

Article Type: Research Article

Abstract: The transfer energy of a magnetorheological fluid (MRF) coupling can be dynamically regulated by changing the MRF mechanical properties of its input and output shafts. In addition, the dynamic characteristics of its drive system can automatically be in the tune with its load characteristics to effectively suppress vibration and shock responses, to achieve overload protection of the system, and to improve its mechanical performance and safety reliability. However, the weak mechanical properties of MRF materials result in so small a coupling torque density that the MRF coupling applications for high-torque transfer is restricted. Thus, to increase the coupling torque density …is becoming an urgent key technological challenge in this field. A technique based on shear-pressure mixed mode was proposed here to increase the torque density by utilizing the formation mechanism of MRF arc flux linkage. Futhermore, a new high torque arc multi-disk MRF coupling structure was designed and its corresponding mechanical torque transfer model was established. A FEA electromagnetic simulation was performed to study the distribution of the magnetic field in the MRF chamber under different current excitations. Effects of the key parameters of the elliptical arc on its transfer torque were also investigated. Finally, experimental analysis of the mechanical properties of the elliptical disk MRF coupling was conducted to verify the feasibility of the proposed technique and the validity of the torque transfer model. Show more

Keywords: Magnetorheological fluid, multi-disk coupling, arc flux linkage, torque density

DOI: 10.3233/JAE-201585

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-20, 2021

Authors: Wu, Guanghua | Liu, Yawen | Zhang, Bo

Article Type: Research Article

Abstract: In this paper, the conformal finite-difference time-domain (CFDTD) technique and the concept of effective dielectric constant are applied to symplectic multi-resolution time-domain (SMRTD) algorithm based on Daubechies scaling functions, resulting in a conformal SMRTD (C-SMRTD) method. Moreover, a novel implementation of perfect matched layer with auxiliary differential equation (ADE-PML) is presented for the SMRTD method. Numerical results of the radar cross section (RCS) of a dielectric sphere verify the effectiveness of the C-SMRTD method, which shows good agreement with the results derived by analytical methods. It is also shown that the accuracy of the C-SMRTD method has been significantly improved …compared with the MRTD method with step approximation, and the proposed method has an advantage over CFDTD at saving the CPU time and memory. Furthermore, a vault-top tunnel model is established with the proposed method, and the characteristic of the field cross-section distribution of the electromagnetic pulse (EMP) propagation in the tunnel model is also presented and discussed. Show more

Keywords: Conformal technique, symplectic multi-resolution time-domain, coarse meshes, RCS, PML

DOI: 10.3233/JAE-201597

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-14, 2021

Authors: Jun, Zhu | Zhenyi, Zhang | Di, Cao | Shaotong, Du | Xiangwei, Guo | Penghui, Liu | Ming, Yang

Article Type: Research Article

Abstract: Aiming at the “light wind start, light wind power generation” of vertical axis wind turbine, a new T-shaped radial passive magnetic bearing with high suspension characteristics is proposed. Passive magnetic bearings used in vertical axis wind turbines usually have small bearing capacity and difficult magnetization. The new T-shaped radial PMB can improve the radial bearing capacity, and the three magnetic rings all adopt simple axial magnetization. The new T-shaped radial PMB is combined with mechanical auxiliary bearing to form the suspension system of wind turbine. In the stable state, the suspension system can realize radial and axial stable suspension. The …structure and working principle of the suspension system are briefly described. Through the finite element simulation, the characteristics of the new T-shaped radial PMB, the traditional double-ring PMB and the T-shaped PMBs are compared. Taking the high bearing capacity and high stiffness of the new T-shaped radial PMB as the optimization objective, the multi-objective optimization of the new T-shaped radial PMB was carried out by changing its geometric parameters (inner diameter, magnetization length and air gap). The research results show that: Under the same bearing capacity, the volume of the new T-shaped radial PMB is reduced by about 78.64%. Under the same volume, its bearing capacity increased by about 30.7%, and its stiffness increased by about 96.1%. After optimization, its radial bearing capacity increased to 101.38 N, and its stiffness increased to 202.76 N/mm. Show more

Keywords: High bearing capacity, high stiffness, new T-shaped radial PMB, multi objective optimization

DOI: 10.3233/JAE-201591

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2021

Authors: Guo, Jiayi | Geng, Jianghai | Lü, Fangcheng

Article Type: Research Article

Abstract: A new core vibration calculation method of UHV shunt reactors is proposed to deal with the problem that vibration parameters of the core of an ultra-high voltage (UHV) shunt reactor cannot be measured on site. A series of tests have validated that the method can calculate the vibration parameters of a UHV shunt reactor core with different voltage ratios. The method is adopted to study the influence of nodal voltage fluctuations of the UHV AC tie line on the core vibration characteristics of a UHV shunt reactor under normal and abnormal operating conditions. The conclusion is drawn as follows: in …the three operating states assessed herein, no matter whether the power grid is in a normal state or not, the core of the UHV shunt reactor will not reach magnetic saturation, and the vibration parameters of the reactor always maintain a linear relationship with the operating voltage. The changes of power grid operation parameters are introduced to the research into reactor vibration, which is conducive to a more comprehensive understanding of the actual operating state of a UHV shunt reactor. It can also provide help for the design and operation of UHV shunt reactors. Show more

Keywords: Shunt reactor, core vibration, voltage fluctuations, magnetic saturation

DOI: 10.3233/JAE-201564

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2021

Authors: Xu, Dongying | Bao, Xiaohua | Xu, Wei | Xu, Yixiang

Article Type: Research Article

Abstract: Synchronous Reluctance Motors (SynRMs) have been widely used in some industrial fields because of their attractive characteristics, such as high efficiency, low cost, and simple structure. In order to reduce the torque ripple of the SynRMs, a non-parametric model is usually used to optimize the rotor structure. However, the conventional method has the problems of the low-accuracy and poor generalization ability. In this paper, an optimization method of the rotor structure is proposed to reduce the torque ripple by utilizing the deep learning algorithm. Firstly, the sample data of the relationship between the rotor structural parameters and torque ripple are …obtained with the finite element analysis (FEA). The fast calculation model is established by the deep neural network (DNN). Then, with the goal of not weakening the torque density and minimizing the torque ripple, the immune clone algorithm (ICA) is utilized to optimize the structural parameters of the rotor at different operating points. Finally, the correctness and validity of the method are verified by the simulation analysis. It is concluded that the accuracy of the model established by DNN is acceptable. The proposed method can significantly reduce the torque ripple and increase the torque density. Show more

Keywords: Deep neural network (DNN), immune clone algorithm (ICA), synchronous reluctance motor (SynRM), torque ripple

DOI: 10.3233/JAE-201577

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2021

Authors: Zhang, Yujiao | Chen, Yanran | Li, Houxu | Huang, Xiongfeng | Yan, Cheng

Article Type: Research Article

Abstract: The live working paths for equipotential operators in the hanging basket method is determined by minimum safety values of various clearances stipulated in regulations. However, the optimization of the safety path planning by the complex gaps is scarce. In this paper, an optimization method for path planning is proposed based on ant colony algorithm. Grid model is established to partition the operation area into different calculation districts, in which key parameters are grid data and obstacle grids. Grid data are the maximum value of the electric field strength on the body surface, calculated by the finite element model. And obstacle …grids are grids that dissatisfy the requirements of complex gaps and their data are larger than the air breakdown field strength. Then ant colony algorithm is employed to search for the best operation path with the minimum working distance and the minimum electric field strength value. After that, an application case is illustrated to demonstrate the optimizing processes. At last, the shock U50 test and power frequency corona discharge test are implemented to verify the safety of the optimized path. Therefore, the path obtained by the proposed method scientifically and effectively shortens the distance of the hanging basket method. Show more

Keywords: Hanging basket method, electric field calculation, finite element method, grid-ant colony algorithm

DOI: 10.3233/JAE-201614

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2021

Authors: Jia, Chen | Xu, Liang | Ji, Jinghua | Zhao, Wenxiang

Article Type: Research Article

Abstract: By incorporating the merits of partitioned stator and flux modulation techniques, the partitioned stator flux modulation motors featuring high torque, have attracted much attention. This paper investigates four partitioned stator flux modulation motors with different types of PM arrays, including surface-mounted type, consequent-pole type, Halbach-array type, and half-Halbach type. The influences of key parameters on the average electromagnetic torque is conducted and compared. Then, based on the optimal designs, four motors are compared in terms of magnetic field distribution, back-electromotive force, torque characteristics, loss and overload ability. The result reveals that the half-Halbach motor is capable of utilizing more PM …to improve electromagnetic torque. Also, the consequent-pole motor achieves the highest torque per PM usage. In addition, performance comparison under the same PM usage is carried out. The result shows that the half-Halbach motor not only exhibits the highest average torque but also achieves the highest PM utilization. Last, the prototype of half-Halbach motor is built for experimental verification. Show more

Keywords: Partitioned stator, permanent magnet motor, Halbach array, flux-modulation

DOI: 10.3233/JAE-201563

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2021

Authors: Gong, Yongxing | Xu, Fengqiu | Xu, Xianze | Zhang, Kaiyang

Article Type: Research Article

Abstract: Precision machining fields require the worktable to have a large-scale multi-degree-of-freedom motion capability. In order to provide a more accurate magnetic model for the control strategy decoupling process and the size parameter optimization design process of the maglev rotary table. This paper proposes a new magnetic modeling method based on the Two-Dimensional Harmonic method. Different from the existing harmonic method, this method simultaneously considers the tangential and radial magnetic field changes of circumferential magnetic array. And it eliminates the edge effect of the magnetic flux density distribution in the radial aperiodic direction. The magnetic force and torque are solved by …the Lorenz integral formula and the Gaussian quadrature method. In order to verify the accuracy of the TDH method, the boundary element software RadiaTM is used for simulation, and a prototype is made for measurement. The experimental results shown that this method reduced the maximum error of the radial edge magnetic field from 104.19% to 3.29%. And it improved the calculation accuracy of magnetic force and torque by 60.74% and 84.39% respectively. This method does not rely on special example, and is beneficial to cross-platform applications. It is more suitable for realizing the magnetic modeling of the maglev rotary table with both rotational motion and large-stroke translational motion. Show more

Keywords: Circumferential magnetic array (CMA), edge effect, maglev rotary table, two-dimensional harmonic (TDH) method, magnetic modeling method

DOI: 10.3233/JAE-201567

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2021

Authors: Fan, Xinyu | Yin, Jie | Su, Shichuan | Pang, Hongyan | Song, Yindong

Article Type: Research Article

Abstract: Electromagnetic valve train (EMVT) can realize independent, real-time and continuous valve motion regulation through the precise motion servo control, which has great potential to improve the efficiency of internal combustion engines. As an electromechanical integration device, EMVT is driven by electric energy, and the loss distribution is complex and changeable under different service conditions. Especially when the EMVT is used in exhaust system, the high gas pressure after combustion will increase the energy loss and operating temperature significantly. In order to improve the device performance, this study analyses the loss distribution and variation law of EMVT under different service conditions. …First, the flux density is obtained by the 3D finite element simulation. In combination with the valve train dynamic Matlab/Simulink model, the copper loss and iron loss of EMVT under typical conditions are explored in detail. Then, the influence of the motion parameters (transition time) and condition parameters (gas pressure) on EMVT’s loss are calculated and analyzed significantly. In the end, the accuracy of the loss models and analysis results is verified by the experiment based on linear load simulator. Show more

Keywords: Electromagnetic linear actuator, loss distribution, camless engine, gas pressure disturbance, dynamic analysis

DOI: 10.3233/JAE-201589

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2021

Authors: Li, Ming | An, Yuejun | Zhang, Zhiheng | Deng, Wenyu | Wang, Guangyu | Qi, Lijun | Kong, Xiangling | Bi, Delong | Shi, Yong | Zhu, Sheng

Article Type: Research Article

Abstract: Canned induction motors fed by inverters are widely used in pharmaceutical, chemical, and nuclear fields. It is necessary to analyse the effect of time harmonic injected by the inverter on the performance of the canned induction motor. However, the existing researches are to consider the inverter and the motor separately, without analyzing the reverse effect of the induction motor as a nonlinear active load on the time harmonics of the inverter. Therefore, this paper establishes a field-circuit coupling analysis model of the canned induction motor considering the influence of load, and studies the effect of time harmonic current under different …load conditions on the electromagnetic field, eddy current loss, and temperature field of the canned induction motor. The paper first uses the analysis method to determine the relationship between the time harmonic voltage of the inverter and the time harmonic current of the motor. Then, the electromagnetic field distribution, eddy current loss, and temperature field distribution of the canned induction motor under different load conditions are calculated. Besides, the laws of time harmonic current on the electromagnetic field, can loss and motor temperature distribution are found. These research results can not only provide a meaningful reference for analysis of the canned induction motor but also provide methods for design optimization and multi-physical field modeling analysis of the canned induction motor. Show more

Keywords: Canned induction motor, time harmonic, can eddy current loss, field-circuit coupling analysis, temperature field

DOI: 10.3233/JAE-201552

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2021

Authors: Heya, Akira | Hirata, Katsuhiro

Article Type: Research Article

Abstract: Space recognition is a crucial issue for autonomous systems such as unmanned aerial vehicles, walking robots, and autonomous cars. These systems are necessary to obtain information using a camera while moving. However, reduction in recognition accuracy and system size increase has created problems. To solve these problems, we proposed the three-degree-of-freedom (DOF) actuator for image stabilization. This paper proposes a novel initial position estimation method and sensorless attitude estimation method for the three-DOF actuator to further downsize and reduce weight. The effectiveness of the proposed methods is verified by a magnetic field analysis, using a three-dimensional finite element method and …numerical simulations. Show more

Keywords: Multiple-degree-of-freedom actuator, three-degree-of-freedom actuator, electromagnetic actuator, sensorless position estimation, image stabilization

DOI: 10.3233/JAE-201537

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2021

Authors: Li, Xiaoning | Wang, Xiaoyuan | Gao, Peng | Gu, Yuxi

Article Type: Research Article

Abstract: The disc coreless permanent magnet synchronous machine (PMSM) has a special coreless structure. This kind of PMSM has very low inductance, which is referred to as the low-inductance PMSM(LIPMSM) in this paper. The LIPMSM offers many advantages to drive systems. However, the current fluctuates strongly when driven by general converters, which makes the LIPMSM difficult to be popularized into modern drive systems. To tackle the above problems, a converter with output inductance is used. The influences of the inductance on the performance of the LIPMSM system are analysed, including current fluctuations, the maximum speed without flux weakening and the current …response time. Based on above analyses, a method of obtaining the optimal inductance is proposed to obtain the optimal inductance simply and efficiently. The method has been verified through simulations and experiments. The system cannot work due to the huge current fluctuations when driven by the general converter. By using the converter with the optimal inductance, the current fluctuations have been reduced to 2 A. The experimental LIPMSM can reach 11000 rpm with very short response time of the current. Therefore, the LIPMSM system performance can been improved significantly and meet the requirements by using the converter with the optimal inductance. Show more

Keywords: Disc coreless permanent magnet synchronous machine (DCPMSM), low inductance, current fluctuations, maximum speed, optimal inductance

DOI: 10.3233/JAE-201605

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2021

Authors: Halim, M.F.M.A. | Sulaiman, E. | Othman, R.N.F.K.R.

Article Type: Research Article

Abstract: The inclusion of high energy density permanent magnet (PM) in MG contributes to the high eddy current loss in magnetic gear and reduces its efficiency. There was limited research done that focused on gear efficiency behavior over a broader range of speed and in different gear ratios. In this paper, the function of gear efficiency concerning gear ratio and rotational speed is proposed. Torque and eddy current loss data were obtained through transient magnetic analysis using finite element software at several rotational ranges and gear ratios. The analytical approach through mathematical substitution was discussed to confirm the finding in the …simulation. The result showed that the gear efficiency decreases as the speed increases. Nonetheless, the gear efficiency revealed improvement in efficiency as the gear ratio increases. Finally, gear efficiency behavior was modeled using the curve fitting method. Subsequently, based on the correlation study, an equation was proposed, yielding a 1% error compared to the new simulated data. With this proposed method and equation, the analysis and estimation of gear efficiency behavior over wider speed and gear ratios are simplified, thus reducing the need to perform simulation over different speeds and gear ratios. Show more

Keywords: Magnetic gear, machine design, gear efficiency, eddy current loss, curve fitting modeling

DOI: 10.3233/JAE-201576

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2021

Authors: Fang, Hong Wei | Wang, Yu

Article Type: Research Article

Abstract: The magnetic gear integrated permanent magnet synchronous generator (MG-PMSG) can reduce the acoustic noise and mechanical loss, which are caused by the mechanical gear box. It also has the merits of increasing efficiency and reducing system volume when it is used for wave energy conversion system. In this paper, an improved bat algorithm (BA) based on velocity weighting factor is proposed. The improved BA is applied for the optimization design of permanent magnet (PM) to reduce the cogging torque of MG-PMSG. The numerical model is constructed by response surface methodology (RSM). The influences of key pole shape parameters on cogging …torque were investigated, including the eccentric distance, the pole-arc coefficient and the permanent magnet thickness. A global optimization design is then carried out by using the improved BA, so that the magnet dimensions corresponding to the optimal cogging torque are obtained. Finally, the performances of the MG-PMSG with the optimized permanent magnet are analyzed by finite element method. Results show that cogging torque, steady torque ripple and back electromotive force (EMF) waveform distortion of the optimized MG-PMSG are reduced. Show more

Keywords: Magnetic gear, wave energy conversion, cogging torque, bat algorithm, response surface methodology

DOI: 10.3233/JAE-201615

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2021

Authors: Lin, James | Harada, Akinori | Oka, Koichi

Article Type: Research Article

Abstract: This papers discusses a method of magnetic levitation which allows a levitated platform to remain both level and zero-power under arbitrary eccentric loading conditions. A hardware system is proposed and developed which laterally displaces hybrid electromagnets (HEMs) to counteract the moments caused by eccentric loads. In this system, the displaced HEMs are the same HEMs which are used for the levitation of the platform. A mathematical formulation is provided to explain the control methodology, and data from successful experimental trials of the developed hardware is discussed.

Keywords: Zero-power levitation, magnetic levitation, tip-tilt control

DOI: 10.3233/JAE-200011

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2021

Authors: Liu, Qing | Zhang, Shiping | Li, Yuanyuan | Lei, Gang | Wang, Li

Article Type: Review Article

Abstract: This paper presents a state-of-the-art survey on the development of the hybrid gas-magnetic bearing (HGMB) technology. HGMBs are proposed to complement the advantages of gas bearings and magnetic bearings for enhanced bearing performance. Nevertheless, there are a number of inherent challenges in their designs, analyses, and performance characteristics that must be taken into account for proper functionality and reliable operation. For this purpose, substantial results in theory, numerical simulations, and experiments concerning rotor dynamics, mechanical structures, control systems, and operation modes are discussed to help further investigation and implementation of HGMBs. In addition, future developments of HGMBs in industries and …remaining challenges are discussed. Show more

Keywords: Hybrid gas-magnetic bearings (HGMBs), rotor dynamics, bearing configuration, hybrid mode

DOI: 10.3233/JAE-201579

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-26, 2021

Authors: Yang, Guohui | Zhang, Chengning | Zhang, Shuo

Article Type: Research Article

Abstract: Permanent magnet synchronous machines (PMSMs) are widely used owing to high power density, high efficiency, etc. Core losses account for a significant component of the total loss in PMSMs beside winding losses. Therefore, it is necessary to consider core losses when designing PMSMs according to actual research applications. In this paper, taking four typical rotor structures (surface-mounted, embedded, “—” shape, “V” shape) as examples, an analysis method is proposed to predict the influence of different rotor structures on core loss of PMSMs. In the case of the same stator and winding structures, due to the influence of the rotor structure …on the magnetic circuit, the corresponding variation law of the magnetic field in the stator core is studied. This method analyzes the radial and tangential components of magnetic flux density vector of the 4 representative points (stator tooth tip, middle tooth and yoke part), and then evaluates the entire core loss through finite element analysis results. In order to verify the method, a prototype was manufactured. The experimental results show good performance of the proposed method of this paper. It provides reference for selecting the appropriate rotor structure and designing the corresponding PMSM according to different specification. Show more

Keywords: Permanent magnet synchronous machines, rotor structure, core loss, magnetic field distribution, magnetic flux density

DOI: 10.3233/JAE-201569

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-14, 2021

Authors: Cheng, Yuhua | Liu, Chunwu | Wang, Minghao | Wang, Gaofeng | Ghovanloo, Maysam | Li, Wenjun

Article Type: Research Article

Abstract: Recent progress on human brain science requires developing advanced neural recording system to capture the activity of large neural populations accurately, across a large area of the brain, and over extended periods. Recently proposed distributed neural recording systems with numerous implanted devices require reliably energizing them wirelessly. Random distribution of these mm-sized implants and brain motion place them at different positions and orientations with respect to the power transmitter. Therefore, traditional wireless power transfer techniques fall short of reaching sufficient power for all implants simultaneously, rendering some implants nonfunctional. In this paper, a three-layer power transmitting array with three-phase coil …excitation current is introduced, which is capable of producing omnidirectional and homogeneous magnetic field across the volume where the Rx coils are located. The individual coil dimensions in the array is optimized to improve the worst-case scenario in terms of homogeneity, which is further verified by the measurements using a scaled-up prototype system. The measurement results show that the minimum received voltages is improved from 0.34 V for 10-mm side-length hexagonal transmitting coil array to 0.83 V for the optimal case, i.e., 35 mm side-length hexagonal transmitting coil array. Show more

Keywords: Omnidirectional, distributed, wireless power transfer, three-phase three-layer coil array, coil radius, optimization

DOI: 10.3233/JAE-201582

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2020

Authors: Wu, Tong | Yu, Guoliang | Pang, Jiarui | Wang, Can | Yang, Han | Qiu, Yang | Zhang, Yi | Zhu, Mingmin | Zhou, Hao-Miao

Article Type: Research Article

Abstract: This work presents an easy way to improve the low-frequency properties in a small-size LTE/WWAN smartphone antenna by just loading a soft magnetic ferrite film on the strong radiation area. The base non-magnetic antenna, which only takes up an 11 mm × 30 mm no-ground space, can achieve hexa-band operation covering 822–914/1710–3244 MHz bands by co-designing a meandering strip and a T-shaped feeding strip. With loading a small-size ferrite film (2 mm × 15 mm) at the strong radiation strip, the frequencies can be shifted to cover the range of 692–1191/1698–3020 MHz, which shows a fully covering of octa-band operation, especially including the best long-term-evolution band, …LTE700, without enlarging the size of base antenna. In addition, the radiation characteristics of the magnetic antenna with ferrite film loading show a limited change at upper bands (1710–2690 MHz) but an acceptable level at lower bands (698–960 MHz). Both experimental and simulated results have been taken out and shown the consistent tendency. This optimization method of low-frequency properties by introducing a commercial ferrite film on the antenna has provided a simple and convenient way to solve the frequency deviation in the practical smartphone applications. Show more

Keywords: Multiband antenna, ferrite loading, frequency modulation, LTE700 band

DOI: 10.3233/JAE-201599

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2020

Authors: Nick, A.S. | Vynnycky, M. | Jönsson, P.G.

Article Type: Research Article

Abstract: A recent three-dimensional (3D) model that revisited earlier theoretical work for longitudinal electromagnetic stirring in the continuous casting of steel blooms is analyzed further to explore how the bloom width interacts with the pole pitch of the stirrer to affect the magnetic flux density. Whereas the first work indicated the presence of a boundary layer in the steel near the interface with the stirrer, with all three components of the magnetic flux density vector being coupled to each other, in the analysis presented here we find that the component along the direction of the travelling wave decouples from those in …the other two directions and can even be determined analytically in the form of a series solution. Moreover, it is found that the remaining two components can be found via a two-dimensional computation, but that it is not possible in general to determine these components without taking into account the surrounding air. The validity of the asymptotically reduced model solution is confirmed by comparing it with the results of 3D numerical computations. Moreover, the asymptotic approach provides a way to compute the time-averaged Lorentz force components that requires two orders of magnitude less computational time than the fully 3D approach. Show more

DOI: 10.3233/JAE-200010

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-27, 2020

Authors: Ma, Yuan | Feng, Wen | Yan, Zhen

Article Type: Research Article

Abstract: The buckling analyses of type-II superconducting strip under applied perpendicular magnetic field and/or distributed uniform mechanical load are investigated in this paper. Based on the Bean critical state model, the electromagnetic body force is firstly given. Then, based on the classical plate theory and two-point initial value method, the critical buckling states of the superconducting strip with different boundary conditions are analyzed. Numerical results show the effects of both the thickness and boundary conditions of superconducting strip on the corresponding critical buckling loads. The present work should be helpful to the research and application of superconducting thin strips.

Keywords: Superconducting thin strip, electromagnetic body force, buckling, critical buckling load

DOI: 10.3233/JAE-190115

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2020

Authors: Zhang, Yuanyuan | Meng, Fanhui | Liu, Zhao | Xing, Manman | Pang, Huaji | Deng, Meng

Article Type: Research Article

Abstract: A satellite remote imaging data is used to describe the actual ground surface around east of Shandong, based on Barrick’s formulations and Wait’s formulations, and considering the time errors due to elongation of the propagation path caused by mountains, this paper comprehensively analyzes the lightning vertical electric field over the actual ground surface. Furthermore, its effects on time-of-arrival (ToA)-based lighting location systems (LLS) are discussed in details and results show that wave-shape and time-delay of the electromagnetic fields can be significantly affected when they propagate over actual ground surface. The time-delay of the field waveform becomes longer with the increasing …roughness, but subtle effect on field peak. After analyzing the actual ground surface around district of Qingdao, this paper reveals the relation between azimuth, observation distance and time-delay. The location error caused by actual ground surface is about several kilometers around the district of Qingdao, and the revised stroke points which are evaluated by the improved actual ground surface propagation model are closer to the actual lightning strike points. Show more

Keywords: Digital elevation model (DEM), lightning vertical electric fields, actual ground surface propagation model

DOI: 10.3233/JAE-201506

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2020

Authors: Chen, Jun-Wei | Liu, Xing

Article Type: Research Article

Abstract: In this paper, the winding inductances of a linear ironless permanent-magnet synchronous actuator for high-precision applications is discussed. Different from rotary motors for conventional applications, high-order harmonics and the end effect due to discontinuous structure are considered. From such considerations, an improved Fourier series expansion is applied to the proposed distributed-parameter model of the linear winding. The calculated inductance matrix is of high accuracy, and presents a new non-uniform form. New features of the inductance matrix are analyzed, and the decoupling scheme is implemented via variable transformation and real-time updating inductances.

Keywords: Winding inductance, linear PM actuator, Fourier series expansion, end effect

DOI: 10.3233/JAE-201571

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-16, 2020

Authors: Guo, Huan | Su, Sanqing | Wang, Wei | Ma, Xiaoping | Yi, Shuchun | Zhao, Xuran

Article Type: Research Article

Abstract: Metal magnetic memory (MMM) testing is a nondestructive approach for evaluating the stress concentration and early damage of ferromagnetic components. However, research on the MMM testing of large steel structures has been limited. Thus, this study investigates the suitability of MMM technology for monitoring the damage in steel structures exposed to complex stresses. The normal components of magnetic signals H p (y ) on the beams and columns of a portal frame are obtained through pseudo-static testing. The signal increment ΔH p (y ) and its absolute value |ΔH p (y )| under different loads are …analyzed. The relationship between the equivalent stress and magnetic signal is investigated through numerical simulation. The results show that the ΔH p (y ) curves are similar during the elastic stage but change abruptly during the plastic phase. Moreover, the differences in the magnetic signal directions caused by the varying detection directions cannot be ignored. In the elastic stage, with the increase in the load, |ΔH p (y )| curves initially increase and then decrease. The formation of the ΔH p (y ) curve is similar to the distribution of the equivalent stress. The mutation of ΔH p (y ) can determine whether a specimen is entering the plastic phase, and can warn against structural failure. The magnetic signal distribution qualitatively reflects the stress distribution. Show more

Keywords: Metal magnetic memory testing, monitoring damage, normal magnetic signals, pseudo-static test, portal frame, equivalent stress

DOI: 10.3233/JAE-190135

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2020

Authors: Li, Jiahao | Yang, Guolai | Fan, Yumeng

Article Type: Research Article

Abstract: This paper provides an analytical method for calculating the electromagnetic field of the tubular linear permanent magnet eddy current brake. The method of separating variables based on Fourier series is used to solve the boundary value problem, and the analytical solution of electromagnetic field is obtained. The braking force is obtained by calculating the Lorentz force. Then the accuracy of the analytical method is verified by comparing the analytical solutions with the solutions obtained by finite element method (FEM). In order to improve braking performance in a limited space, the parameter analysis is carried out to investigate the influence of …various structural parameters on the braking characteristics. According to the results of parameter analysis, the range of design parameters is determined. Finally, a multi-objective optimization is applied to find the optimal design parameters of the eddy current brake. The braking force increases by 27% and the volume of permanent magnet decreases by 7.7% after optimization. Show more

Keywords: Eddy current brake, braking force, finite element method, genetic algorithm, Halbach array

DOI: 10.3233/JAE-201523

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-23, 2020

Authors: Li, Zixuan | Yang, Guolai | Wang, Liqun

Article Type: Research Article

Abstract: This paper investigates the damping and demagnetization effect of an electromagnetic buffer (EMB) under impact load. The motional eddy currents are calculated first, and the Ampere circuital theorem is employed to calculate the induced magnetic field. The demagnetization effect is formulated by the magnetic Reynolds number with a correction coefficient k m . Following this, the time-step finite element (FE) model of the buffering system is constructed based on the nonlinear B–H curve. The accuracy and feasibility of the FE model is preliminarily verified by small-scale impact test. The characteristics of damping displacement, velocity, damping force and damping coefficient are …obtained. Then, the demagnetization effect is analysed by eddy current, magnetic field distribution, through the intensive impact load test at room temperature and time-step FE model. The value of k m is obtained through the intensive impact test and the simplified expression of critical velocity. The results show that the demagnetization effect is obvious with the increase of velocity. By introducing the correction coefficient of magnetic Reynolds number, the eddy current demagnetization process is more realistic. Show more

Keywords: EMB, intensive impact load, demagnetization, magnetic Reynolds number, critical velocity

DOI: 10.3233/JAE-201556

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2020

Authors: Qiao, Yukai | Wang, Yinshun | Yuan, Xi | Zhang, Guangyi | Pi, Wei

Article Type: Review Article

Abstract: High temperature superconducting (HTS) magnets have widespread applications in a strong and steady magnetic field at low temperature. However, they can not be operated in persistent current mode (PCM) due to their immature joint technique without resistance. In order to realize the PCM, an HTS magnet stacked by double-hole rectangular HTS plates was proposed and fabricated. The trapped field of the HTS magnet was measured and simulated under four kinds of magnetization methods, field cooling (FC), zero field cooling (ZFC) and inner magnetization (a solenoid is placed at right/left hole of double-hole rectangular HTS magnet to magnetize HTS magnet) as …well as combination of both methods. Meanwhile, the H-formulation is applied to the 3D model to analyze the electromagnetic behaviour. It was found that the trapped field of double-hole rectangular HTS magnet magnetized by FC with inner magnetization or ZFC with inner magnetization is higher than pure FC or ZFC magnetization. In inner magnetization, the trapped field of one hole in HTS magnet has no effect on the other one. In addition, the experiment results are in good agreement with numerical analysis, which can provide significant references for the magnetization method. Show more

Keywords: Double-hole, FC, rectangular HTS magnet, trapped field, ZFC

DOI: 10.3233/JAE-201530

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2020

Authors: Alharbi, Khalid Hamed | Moniruzzaman, Md. | Aldhaheri, Rabah W. | Aljohani, Abdulah Jeza | Singh, Simranjit | Samsuzzaman, Md | Islam, Mohammad Tariqul

Article Type: Research Article

Abstract: In this paper, a monopole antenna with Ultra-wideband (UWB) characteristics is presented for applications in 5G and short-distance wireless communications. It consists of a rectangular shaped patch having truncated corners and central notch with an extended stub at top edge. Two layers of slots are engraved in the middle of the patch within which the outer layer contains four L shaped slots and the inner layer contains two face to face vertically placed U-shaped slots. A partial ground is structured with staircase slots to attain ultra-wideband response with sufficient gain and efficiency. The proposed antenna provides 124% of impedance bandwidth …(2.8 GHz–12 GHz) implemented on a low-cost FR4 substrate having the electrical dimension of 0.3𝜆 × 0.19𝜆 at the low cutoff frequency. The effect of the inclusion of slots within the patch is clearly observable as it increases gain and efficiency. The proposed antenna exhibits better response with a maximum measured gain of 6.5 dBi and efficiency 85% within the bandwidth. Near constant time delay around 1 nS and good fidelity factor of 0.8316 represents that this slotted antenna can be used for undistorted reliable signal transfer. This antenna also provides symmetrical radiation patterns with less cross-polarization effects. Therefore, this monopole antenna can be an appropriate candidate for short-range communication applications like 5G, wireless local area networks, transfer data from biomedical sensors and imaging. Show more

Keywords: Ultra-wideband, defected ground structure, monopole, slotted patch, 5G wireless communication

DOI: 10.3233/JAE-201553

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-22, 2020

Authors: Liu, Qing | Wang, Li | Zhang, Shiping | Li, Yuanyuan | Lei, Gang

Article Type: Research Article

Abstract: Active magnetic bearings (AMBs) bring extraordinary benefits such as free of contact, elimination of lubrication, active control of rotor position, and a built-in monitoring system. In the design of AMBs, the bearing structure is of significance since it has an important impact on bearing performances. However, the effect of winding configurations of AMBs is still obscure. In this paper, the system-level implications of two radial AMB winding configurations termed the Ortho and the Cross types are investigated, including the bearing characteristics, power consumptions and rotor dynamic behaviors. The simulation results demonstrate that the Cross type contributes to larger load capacity …in the direction of gravity. In condition of a heavier gravity load (−200 N), the Cross-type winding configuration saves power consumption with a percentage of 17.2% at steady state (20,000 rpm) and 12.7% considering unbalance mass during the run-up process. However, the rotor vibrations of the Cross type in case of external loads and unbalance mass are larger than the Ortho type. The proposed results of this paper provide some useful information for the AMB winding configuration design. Show more

Keywords: Active magnetic bearing, winding configuration, power consumption, rotor dynamics

DOI: 10.3233/JAE-201502

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2020

Authors: Zhang, Xiwei | Li, Lin | Pang, Jian

Article Type: Research Article

Abstract: In this paper, both nanocrystalline alloy (Fe73.5 Cu1 Nb3 Si15.5 B7 ) ribbon samples and toroidal samples (wound ribbon) are annealed at different temperatures in order to consider the influence of inner stress on the magnetization properties. Then the AC magnetization properties of these samples are measured. Combined with the measured results, the influence of inner stress on nanocrystalline alloy’s microstructure is analyzed quantitatively based on the loss separation principle and the statistical theory of loss. By comparing measured macroscopic magnetization characteristics and excess loss, the equivalent stress state of the toroidal sample is evaluated. Furthermore, two kinds of samples’ …excess loss under different annealing temperatures are analyzed, and the effectiveness of stress relief at optimal annealing temperature is validated. Show more

Keywords: Nanocrystalline alloy, loss separation, excess loss, annealing, stress relief

DOI: 10.3233/JAE-201532

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2020

Authors: Yuan, Hao | Zhao, Ximei | Fu, Dongxue

Article Type: Review Article

Abstract: In this paper, a novel high-precision motion control is proposed for a permanent magnet linear synchronous motor (PMLSM) servo system, which is vulnerable to the influence of uncertainties. First, the dynamics of the PMLSM with uncertainties are derived. To cater for the parametric uncertainties, the model-based feedforward control is constructed so that the transient response of the system is improved. Moreover, the adaptive jerk control (AJC) scheme based on a robust integral of the sign of the error (RISE) feedback is adapted to restrain the uncertainties such as external disturbance and nonlinear friction in the system. To alleviate the chattering …phenomenon, a novel exponential adaptive law is designed to bound the feedback gain of the jerk, under the condition of the initial term of control efforts considered. Then, the jerk signal is integrated to form the feedback control law, which generates continuous control input and ensures the stability of the system. Compared with sliding mode control (SMC), the experimental results indicate that both the robustness and tracking performance of the system are significantly improved without adding more control efforts. The position tracking error is reduced and high-frequency oscillation is effectively attenuated. Show more

Keywords: Permanent magnet linear synchronous motor (PMLSM), adaptive jerk control (AJC), robust integral of the sign of the error (RISE) feedback, robustness, chattering

DOI: 10.3233/JAE-201558

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2020

Authors: Shahid, A. | Ali Abbas, M. | Huang, H.L. | Mishra, S.R. | Bhatti, M.M.

Article Type: Research Article

Abstract: The present study analyses the dissipative influence into an unsteady electrically conducting fluid flow embedded in a pervious medium over a shrinkable sheet. The behavior of thermal radiation and chemical reactions are also contemplated. The governing partial differential equations are reformed to ordinary differential equations by operating similarity transformations. The numerical outcomes for the arising non-linear boundary value problem are determined by implementing the Successive linearization method (SLM) via Matlab software. The velocity, temperature, and concentration magnitudes for distant values of the governing parametric quantities are conferred, and their conduct is debated via graphical curves. The surface drag coefficient increases, …whereas the local Nusselt number and Sherwood number decreases for enhancing unsteadiness parameter across suction parameter. Moreover, the magnetic and suction parameters accelerate velocity magnitudes while by raising porosity parameter, velocity decelerates. Larger numeric of thermal radiation parameter and Eckert number accelerates the temperature profile while by enhancing Prandtl number it decelerates. Schmidt number and chemical reaction parameters slowdowns the concentration distribution, and the chemical reaction parameter influences on the point of chemical reaction that benefits the interface mass transfer. It is expected that the current achieved results will furnish fruitful knowledge in industrious utilities. Show more

Keywords: Electrically conducting fluid, Darcy flow, radiation, shrinking sheet, permeable medium

DOI: 10.3233/JAE-201540

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-14, 2020

Authors: Liang, Yongli | Xu, Lizhong

Article Type: Research Article

Abstract: In this paper, the structure and operating principle of the electromagnetic harmonic movable tooth drive system is introduced. Equations of the magnetic density and the electromagnetic force are given. The force model on the flexible wheel under magnetic force is presented. The equivalent concentrated force applied to the flexible wheel is determined. Based on it, the displacement equations of the flexible wheel are deduced. Using these equations, the displacement distribution of the flexible wheel and its changes along with the main parameters are investigated. Relationship between coil current and the maximum radial displacement is determined. The limit current corresponding to …the limit radial displacement is obtained and its changes along with the main parameters are analyzed. The results show that the displacements of flexible wheel increase with the radius of flexible wheel and the coil current, and decrease with the initial air gap and the thickness of flexible wheel. A limit current under which the flexible ring will be buckled occurs under electromagnetic force. The limit current corresponding to the limit displacement increases with the thickness of flexible wheel, the pole pair number and the air gap, and decreases with the radius of flexible wheel. The results can be used to design and analyze the drive system. Show more

Keywords: Electromagnetic drive, harmonic drive, displacement, force model, limit current

DOI: 10.3233/JAE-201546

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2020

Authors: Wojciechowski, Rafal M. | Kurzawa, Milena | Jedryczka, Cezary

Article Type: Research Article

Abstract: The paper discusses the strategy of searching for the extreme of multi-modal functions with the number of decision variables n ≥ 6, in a multidimensional design space. The optimization algorithm combining an evolution strategy (ES) with operators of a genetic algorithm has been proposed. The method of selecting subspaces that allows for narrowing of the design space has been proposed. The effectiveness of the proposed approach has been demonstrated on two selected test systems with eddy currents. First, the equivalent multi-branch Foster circuit of a solenoid coil with a massive conducting core has been determined. Next, the proposed …approach has been applied in the analysis of a high frequency transformer, working in a wireless power transmission (WPT) system. In the second case, the equivalent circuit of the transformer has been formed by means of multi-branch Cauer circuits. Selected results of the calculations have been presented and discussed. The obtained results have been compared with the results of the performed finite element analysis (FEA) of the considered test systems. Show more

Keywords: Optimization, genetic algorithm, eddy current problem, Foster circuit, Cauer circuit

DOI: 10.3233/JAE-200901

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2020