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

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190044

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

Authors: Du, Chuanbao | Liu, Zheng | Mao, Congguang | Qin, Feng | Cui, Zhitong | Sun, Dongyang

Article Type: Research Article

Abstract: This paper examines with statistical analysis of transient response for typical vehicle mounted antenna - monopole on conductive plane varying multiple random field parameter distributions of high-altitude electromagnetic pulse (HEMP) by employing the combinations of Method of Moment (MoM) method and a high computational efficiency statistical analysis tool called polynomial chaos expansion method (PCEM).The main procedures of the combination method are composed of two following steps: Firstly, the frequency-domain transfer function of the antenna port response for the monopole is derived by using MoM and then the transient current response is obtained with inverse Fourier transform; Secondly, the statistical model …with multiple random input parameters are calculated by PCEM according to the transient response data. The statistical indicators of the model concentrate on the confidence interval of the transient response, the Probability Density Function (PDF) and Cumulative Probability Density Function (CDF) of the current peak. The paper not only focuses on the random radiated field parameter such as elevation, azimuthal angle, polarization angle and magnetic dip angle but also considers height of burst, ratios of plane length versus antenna height, and antenna down-tilt angles. The analysis results demonstrate the validation of the proposed statistical method and provide the reference base for system HEMP survivability evaluation and protection design. Show more

Keywords: Monopole, HEMP, uncertainty analysis, MoM, PCEM, transient response

DOI: 10.3233/JAE-190125

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

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190073

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

Authors: Pilat, Adam Krzysztof

Article Type: Research Article

Abstract: This elaboration presents an initial study of the elliptic rotor driven by the active magnetic bearing consisting of 6 poles. The analysis was realized using the virtual prototype - a numerical model of device. The model was realized with support of COMSOL Multiphysics software. The proposed geometry, selected materials and configuration were used to perform analysis if the electromagnetic forces and torque are available to drive the rotor of the elliptic shape. The control study is given to obtain a rotational motion for a fixed rotor placement at the bearing center. Numerical simulations were realized to demonstrate features and limitations …of the proposed solution. The solution in a form of Virtual Prototype allows to eliminate prototyping costs and extends the knowledge and dependencies of complex mechatronic systems like active magnetic levitation technology based ones. Show more

Keywords: Active magnetic bearing, elliptic rotor, control, virtual prototype

DOI: 10.3233/JAE-209006

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

Authors: Zhao, Xingqian | Shuai, Changgeng | Xu, Wei | Chen, Demin | Hu, Zechao

Article Type: Research Article

Abstract: To isolate the vibration transmitted from the propeller to the vessel’s hull, the main engine, the shaft together with the bearings are proposed to be installed on a large-scale isolation system. Permanent magnetic thrust bearing (PMTB) is applied to further reduce the vibration transmission. The Coulombian model is adopted to calculate the force and stiffness, which determine the application feasibility of the PMTB in vessels. Explicit computations are presented for stacked PMTB. The calculation result is compared with that obtained by finite element method (FEM) and experimentally tested. It is revealed that the Coulombian model is accurate enough and more …economic than the FEM, which make it advantageous to the structure design and parameter optimization of PMTB. In the influence study by Coulombian model, it is found that the airgap width can exponentially change the maximum axial magnetic force and stiffness; the radial width is not a sensitive factor for both force and stiffness; the axial length should be 4/5 of the radial thickness to obtain the largest force and decent stiffness. Show more

Keywords: Permanent magnetic thrust bearing, coulombian model, finite element method, parameter optimization, magnetic force and stiffness

DOI: 10.3233/JAE-209007

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

Authors: Zhou, Ran | Yan, Mingyin | Guo, Yongquan | Jin, Junjie | Sun, Feng | Zhang, Xiaoyou | Oka, Koichi

Article Type: Research Article

Abstract: A proposed permanent magnetic suspension using flux path control mainly consists of a disk permanent magnet, two pairs of F-shape core and a servo motor, and controls the suspension force by changing flux path, and the load on the motor shaft is eliminated due to its symmetric offset optimal structure to make the motor reach zero power output. In order to verify the robustness of the system under external disturbances, this paper investigates and analyzes its suspension characteristics by using the simulation and the experiment. Firstly, the structure and the suspension principle of the system are introduced. Secondly, the dynamic …model is established, two kinds of controllers of the system are designed with the classic PD control method. Finally, the suspension characteristics of the system are studied through the simulation and the experiment. In the process of the experiment, the system is subjected to small step disturbance or small force disturbance, under the action of the real-time control system. The experimental results show that when the system is subjected to small step disturbance or small force disturbance in the process of the suspension, the suspended object will reach a new equilibrium position under the action of the real-time control system. Show more

Keywords: Permanent magnetic suspension, flux path control, zero power, PD control

DOI: 10.3233/JAE-209008

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

Authors: Gao, Tian-yu | Zhou, Jin | Zheng, Ya-wei | Xu, Yuanping

Article Type: Research Article

Abstract: The high speed magnetic levitation turbine generator used in Organic Rankine cycle (ORC) system will produce wind friction loss due to the high density of work environment and high eddy current loss in the part of permanent magnet (PM) rotor, which obviously effect the performance and stability of PM. In order to minimize the loss of PM rotor, this paper presented a comprehensive optimization design for the stator and rotor structure of turbine-generator. Firstly, the physical performances coupled with design variables, such as loss, generator power, rotor dynamic, strength and axial force of AMB were analyzed, mainly analyzed the structural …variables coupled with design variables due to the effects of single constraint and the decoupling methods, which eliminated irrelevant variables in the final optimization. Neural network was used to establish agent models for each physical performance and brought into comprehensive optimization process of total PM rotor, which greatly improved the efficiency of optimization. The result of optimization is that the total rotor loss decreased 15.3% and all of other physical performance meet the requirements. Show more

Keywords: turbine generator, rotor loss, coupled structure variable, agent model, comprehensive optimization

DOI: 10.3233/JAE-209001

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

Authors: Gloess, Rainer | Goos, Alexander

Article Type: Research Article

Abstract: This article describes design rules for the magnetic constrains, the sensors and the controller for planar and linear stages for a scanning application with a resolution at nanometer level. The main advantage of magnetic levitated systems in relation to “standard” air bearing systems or mechanical guided systems is that they provide perfect cleanroom conditions. The other advantage is that there is no influence by inaccurate guiding. Because of closed-loop control in all 6 DOFs, there is also stationary accuracy and the highest repetition, which only depends on the resolution of the hysteresis-free sensor system. Most of industrial applications require free …access to the movable top plate, requiring that all types of sensors should be placed below the platform. The main challenge for pushing the technology into “industry nanometer level” is how to get it to work with low-price distance sensors at nanometer resolution and a motion range of millimeters. A key point is the design of the controller structure for fast access of the actuators and many sensors, in case of the new planar system there are 24 coil pairs and 23 sensors working in the servo loop at 20 kHz. Show more

Keywords: Magnetic levitation, incremental optical sensors, Halbach array, field mapping

DOI: 10.3233/JAE-209003

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

Authors: Ahmed, Firdausa | Kalita, Karuna

Article Type: Research Article

Abstract: Due to the salient features of stator and rotor in Switched Reluctance Motor the air-gap of the machine does not remain uniform during its motoring operation. This innate characteristic is responsible in producing considerable amount of radial force in the motor. However, on the other hand eccentricity or radial displacement of the rotor is another key cause to this production of radial force. In this paper a single winding structure called bridged configured winding in a 12/8 BSRM is delineated which can be used to deploy the radial displacement by injecting controlled current within the same winding. Initially a mathematical …model of the motor is developed and verified using finite element modeling. The developed model is analyzed by integrating a voltage source asymmetric converter for motoring operation and separate asymmetric converters for injecting currents into the winding to control the radial displacement of the motor. Investigations of radial forces at various rotational positions and controllability of radial displacement are carried out using a simple PID controller system. Show more

Keywords: Bearingless Switched Reluctance Motor (BSRM), Bridge Configured Winding (BCW), Finite element model, radial force, radial displacement, Switched Reluctance Motor (SRM)

DOI: 10.3233/JAE-209005

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-20, 2020

Authors: Rodriguez, Elkin | Costa, Felipe | Stephan, Richard

Article Type: Research Article

Abstract: Magnetic bearings offer the best solution to mitigate mechanical friction. A variety of geometries and new materials are being studied. The advantage of using a passive bearing system, like the Superconducting Magnetic Bearing (SMB), is that it offers low friction without the need of feedback control, increasing the reliability and decreasing the energy consumption. SMB devices work at very low temperatures that are often achieved with the use of Liquid Nitrogen inside of cryostats. This paper describes the design and experimental tests of a SMB passive magnetic bearing system. An innovative design of a cryostat that uses YBCO bulks …refrigerated by a cryocooler is presented. With this setup, it is possible to perform vibration tests in several temperatures from 45K up to 77 K to find the resonance speeds at each temperature. Pieces of equipment that use SMB can benefit from reducing the working temperature. The mechanical response of the pinning force may vary with the choice of refrigeration used. To perform those tests, units of accelerometers are installed on the rotor body and displacement sensors monitor the behavior as function of the rotor speed. This improved magnetic bearing will be used in energy storage systems to reduce the instability of the rotor used in flywheel applications by changing the refrigeration temperature of the superconductor. This investigation can lead to an improvement of the levitation force, the levitation gap and damping. Show more

DOI: 10.3233/JAE-209004

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

Authors: Yao, Yichen | Ma, Yanhui | Su, Yixin | Su, Jiageng | Yu, Suyuan

Article Type: Research Article

Abstract: Active magnetic bearings (AMBs) have been extensively used in the vibration reduction of rotating machinery because of active control technology. In fact, the mechanical characteristics of the magnetic bearing are also important for vibration isolation as the main vibration transmission path. In this paper, a finite element (FE) model of a 30 kW magnetic suspended prototype pump suspended by 5-DOF AMBs was established to simulate the vibration transmission of the system. Two external excitations, unbalanced force of the rotor and hydrodynamic force acted on the impeller were considered. Based on the model, several main factors that affect the vibration transmission of …magnetic suspended pump were investigated, such as mass distribution of the system, the equivalent stiffness of the AMBs and the rubber vibration isolators were investigated. Based on the above work, a new magnetic suspended pump was developed. The results of simulation and experiments show that the new design can effectively reduce the vibration transmission of the system. Show more

Keywords: Active magnetic bearings, magnetic suspended pump, equivalent stiffness, vibration isolation, model

DOI: 10.3233/JAE-209002

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

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190087

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-20, 2020

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190109

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

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190051

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

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190092

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

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

Article Type: Research Article

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

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

DOI: 10.3233/JAE-190113

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

Authors: Qiu, Li | Deng, Kui | Li, Yantao | Tian, Xi | Xiong, Qi | Chang, Peng | Su, Pan | Huang, Lantao

Article Type: Research Article

Abstract: The long-life driving coil is the prerequisite for electromagnetic forming industrial application. Up to date, the temperature rise is one of the major factors that restrain its working life. For the purpose of reducing the temperature rise of the driving coil, this paper proposes a new coupled cooling method, in which an extra cooling coil is placed on one side of the driving coil, then the Joule heating is coupledly transferred by delaying the breakover control of the driving coil. To achieve this purpose, a finite element simulation model of Electrical Circuit- Electromagnetic Field-Thermal Coupling in the plates setting of …the electromagnetic forming is established, after which the influence rules of coil turns, cross-sectional area and materials of cooling coil on temperature rise are analyzed. Then, this paper also establishes a coupled cooling circuit model, in which the influence of cooling coil structure parameters on the Joule heating of driving coil is analyzed. Furthermore, Simulation results show that effective Joule heating transfer can be reached by the best optimization scheme of the cooling driving coil. Specifically, the average temperature rise reduces by 13 degrees, namely 22.8% by using this new method. Show more

Keywords: Electromagnetic forming, driving coil, temperature rise, Joule heating

DOI: 10.3233/JAE-190062

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

Authors: Zhang, Yunfeng | Gu, Jialiang | Zhang, Erchun

Article Type: Research Article

Abstract: Studying underground propagation effects of lightning electromagnetic fields in different geological environments will contribute to more reasonable designs for protecting underground cables and electronic equipment. In this paper, we have analyzed influences of different geological environments, depths and soil water content on underground propagation of lightning electromagnetic fields in detail by using the nite difference time domain (FDTD) method in the 2-D cylindrical coordinate system to calculate components of underground electromagnetic fields at a horizontal distance of 200 m, including vertical electric field E z , horizontal electric field E r and azimuthal magnetic field H 𝜑 …. The results show that the underground electric field is predominantly horizontal. Propagation of lightning electromagnetic fields in wet clay and wet limestone environment changes significantly compared to freshwater environment. Attenuation is larger with depth in wet clay and wet limestone, while propagation is unaffected in freshwater. When water content in soils ranges from 5% to 25%, the vertical electric field has the largest attenuation and the azimuthal magnetic field has the least attenuation. The electromagnetic fields in clay are most sensitive to changes in water content. Show more

Keywords: FDTD, lightning electromagnetic fields, different geological environments, water content, underground propagation

DOI: 10.3233/JAE-190112

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

Authors: Yang, Xiaolong | Sun, Peng | Hao, Fuxiang

Article Type: Research Article

Abstract: In order to improve the pressure capability of the ferrofluid seal under the condition of large sealing gap, a diverging stepped ferrofluid seal with a large gap and two magnetic sources was designed. The magnetic field distributions in the gap of the ferrofluid seal were calculated by finite element method. The effects of the pole teeth number, the height of the pole teeth and the sealing gap on the pressure capabilities of the diverging stepped ferrofluid seal are studied and compared with ordinary ferrofluid seal. The results show that the change of the radial pole teeth number has little effect …on the pressure capability of the stepped ferrofluid seal. The pressure capability of stepped ferrofluid seal decreases with the increase of the axial pole teeth number. The pressure capability of the stepped ferrofluid seals reach maximum when the radial and axial pole teeth height is 0.6 mm. The pressure capability of stepped ferrofluid seal decreases as the radial sealing gap increases. The pressure capability of stepped ferrofluid seal decreases firstly and then increases with the increase of the axial sealing gap. Comparing with ordinary ferrofluid seal, the stepped ferrofluid seal has better pressure capability. Show more

Keywords: Large gap, diverging, ferrofluid, seal, numerical simulation

DOI: 10.3233/JAE-190127

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

Authors: Zhang, Jin | Zhang, Qiuju

Article Type: Research Article

Abstract: The purpose of this paper is to optimize the PM arc ratio of consequent pole permanent magnet vernier machine (CP_PMVM). The operation principle of the CP_PMVM is discussed. An optimization parameter K 𝛼 related to the PM arc ratio is derived. For the CP_PMVM, the amplitudes of the 4th and 14th order harmonics of the air-gap flux density, the amplitude of the back electromotive force (back-EMF) and the average torque all have positive correlations with K 𝛼 . The optimal PM arc ratio is 0.64. The three phase inductances are approximately constants, and the d -axis inductance is equal …to the q -axis inductance. The PM flux linkages are sinusoidal. The no-load back-EMF waveform of the measured phase is nearly sinusoidal. The gear ratio of the CP_PMVM evaluated from the back-EMF is close to the design value. Furthermore, a controller according to the mathematical model is designed. The CP_PMVM vector control with a sliding-mode (SM) speed controller exhibits a smooth starting, and has an anti-jamming capability. Show more

Keywords: Consequent pole (CP) rotor, permanent magnet vernier machines (PMVM), sliding mode (SM), vector control

DOI: 10.3233/JAE-190061

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

Authors: Hasan, Alfaisal A. | Mekheimer, Khaled S. | Tantawy, Bassem E.

Article Type: Research Article

Abstract: The present work studies magnetohydrodynamic stability with streaming resistive triple superposed fluid layers. This system is influenced by an oblique magnetic field. The solution of motion equations by using the method of perturbation analysis under the boundary conditions which leads to deriving the dispersion relationship describing the behaviour of the perturbed and unperturbed system. The effect of different parameters on the stability and the instability of this system was studied. Regions of stability and instability are identified by drawning the curves to illustrate the regions of stability and instability behaviour. It is found that the magnetic field permeability coefficient, the …intensity of the magnetic field values, the increase of the fluids density values and the streaming velocity have destabilizing influences on the considered system. The presence of an oblique magnetic field plays a stabilizing role and can be used to retard the destabilizing influence. Show more

Keywords: Self-gravitating, resistive, superposed fluids, streaming, oblique magnetic fields

DOI: 10.3233/JAE-190110

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

Authors: Li, Peng | Jiang, Jiafu | Liu, Sheng | Fu, Peng | Huang, Yiyun | Hui, Xie | Qiang, Liu | Hongyan, Zuo

Article Type: Research Article

Abstract: As an important electrical power distribution system of ITER (International Thermonuclear Experimental Reactor) device, PPEN (Pulsed Power Electrical Network) feeds the pulsed loads for the superconducting coils and the heating and current driving systems. The PPEN transforms 400 kV power grid to 66 kV and 22 kV distribution voltage levels by 3 main step-down transformers. In this paper, the power loss of PPEN transformer is analyzed and calculated. The 2D PPEN transformer model is built. The temperature rise of PPEN transformer is calculated by ANSYS software. To validate the feasibility and correctness of the proposed method, the temperature rise test of PPEN transformer …is carried out, then the related results are compared with the test data. Show more

Keywords: ITER, PPEN, temperature rise, ANSYS, short-circuit method

DOI: 10.3233/JAE-190105

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

Authors: Bai, Peigen | Shi, Pengpeng | Zhao, Yingsong | Chen, Hong-En | Xie, Shejuan | Chen, Zhenmao

Article Type: Research Article

Abstract: As one typical material of nuclear power plant structure, austenitic stainless steel (SS) is often accompanied by residual stress and plastic deformation during their manufacture and application, which may affect the structure service safety. In this paper, the effects of the composite state of residual stress and plastic deformation on the pulsed eddy current testing (PECT) signals of SS are studied theoretically and experimentally. By considering the electromagnetic properties in the composite state, the PECT theory is established for the 304 SS in the composite state. The numerical simulation is completed using the reduced vector potential method and the verification …experiment is also carried out. The comparison between simulation and experimental results shows that the peak value of the PECT signal increases with the increase of plastic deformation or residual stress. This means that if the residual stress is not considered in the composite state, the effectiveness of the PECT method for evaluating plastic deformation may be seriously affected. Show more

Keywords: 304 austenitic stainless steel, composite state, plastic deformation, residual stress, pulsed eddy current testing

DOI: 10.3233/JAE-190124

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

Authors: Chang, Jiujian | Fan, Yanen | Zhu, Bo | Luo, Liang | Wu, Jinglai | Pan, Yishan | Kang, Peng

Article Type: Research Article

Abstract: This paper takes the demand of high power density motor for new energy vehicles as the application background. In order to solve the problem of low power density of radial flux motor, a novel direct cooling yokeless and segmented armature axial flux machine (YASA) is proposed. The thermal-fluid multi-physical coupling field of YASA motor has been studied by combining numerical analysis and computational fluid dynamics (CFD). On this basis, the internal relationship among the output power, flow resistance and structural parameters of the cooling system has been studied, and then the parameters of cooling system has been multi-objectives optimized. On …the premise of meeting the pressure loss of the cooling system, the heat transfer efficiency has been improved, and then the output power of the motor has been increased. Show more

Keywords: YASA, cooling system, power density, CFD, pressure loss

DOI: 10.3233/JAE-190085

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 | Ge, Yulei

Article Type: Research Article

Abstract: In actual operation, the skin effect electric heat tracing system is powered by the inverter circuit, and the higher harmonic components are inevitably introduced. There is not much research on the influence of harmonic current on the electric heat tracing load loss. In this paper, the harmonic distribution under PWM driving mode is analyzed, and the load loss of the electric heat tracing body under harmonic current is derived. The co-simulation method of PWM inverter circuit and skin electric heat tracing body coupling is proposed. The simulation results of current and loss of co-simulation method and sine wave driving method …are compared. The results show that the parameters of PWM driving mode increase to different degrees, which proves the correctness of the joint simulation method. At the same time, the influence of the output characteristics and modulation parameters of the PWM inverter circuit on the load loss of the electric heat tracing body is analyzed, which provides a theoretical basis for the determination of the parameters of the inverter circuit. In addition, combined with multi-physics coupling analysis, this paper obtains more accurate temperature distribution results of the electric heat tracing system without scaling the size of the electric heat tracing ontology. Not only can we intuitively understand the material selection and hot spot configuration of the electric heat tracing components, but also further understand the influence of current harmonics on the load loss in actual operation, so as to better realize the efficient heat tracing of the skin electric heat tracing system. Show more

Keywords: Electric heat tracing system, harmonic analysis, loss calculation, co-simulation, multi-physics coupling analysis

DOI: 10.3233/JAE-190106

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 | Cai, Yingfeng | Zhao, Dean | Yang, Zebin

Article Type: Research Article

Abstract: The traditional displacement sensors used in the bearingless induction motors (BIM) have many disadvantages, such as high cost, poor temperature stability, low conversion efficiency and complex motor operation. To improve these disadvantages, the detailed study on the novel displacement sensorless control based on the model reference adaptive system (MRAS) is presented in this paper. Firstly, the principle of radial suspension force generation and the mathematical model of the BIM are introduced. Secondly, the basic structure of the proposed MRAS is constructed and the stability is verified by the Popov’s integral inequality. Thirdly, to improve the control accuracy and dynamic characteristics …of sensorless vector control system, a method of directly controlling rotor eccentric displacement by using suspension force compensation is proposed. Finally, the feasibility and accuracy of the proposed method have been verified by the simulation and experimental results. According to the results obtained, the radial displacement of the rotor can be accurately estimated, and the rotor displacement sensorless control of the BIM based on MRAS is achieved. Show more

Keywords: Bearingless induction motor, model reference adaptive system, rotor displacement sensorless control, direct suspension force control

DOI: 10.3233/JAE-190118

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

Authors: Yao, Wang | Hai Tao, Yu | Rong, Guo | Dong Yang, Li | Ningjun, Feng | Zheng, Xu

Article Type: Research Article

Abstract: An extended state observer (ESO) based fuzzy adaptive sliding mode control (FASMC) for permanent magnet synchronous motor (PMSM) drive system is proposed in this paper. In order to improve the disturbance rejection property, a dynamic disturbance compensation method is developed based on extended state observer. A fuzzy adaptive sliding mode control method with a novel sliding mode reaching law is presented to enhance the tracking performance. Then, the proposed method called FASMC-ESO, is applied to regulate the speed of PMSM. The global asymptotic stability analysis of the system is proved by Lyapunov functions. Comparative simulation and experiment results verify the …effectiveness of the proposed method. Show more

Keywords: Disturbance observer (DO), permanent magnet synchronous motor (PMSM), fuzzy adaptive (FA), sliding mode control (SMC), extended state observer (ESO)

DOI: 10.3233/JAE-190098

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

Authors: Zuki, Nor Aishah Md | Othman, Raja Nor Firdaus Kashfi Raja | Ahmad, Suhairi Rizuan Che | Shukor, Fairul Azhar Abdul

Article Type: Research Article

Abstract: This paper discusses the constants in various types Double Stator Permanent Magnet Brushless DC Motor (DSPM BLDC). Hybrid or electrical vehicles requires fast response motor that are capable of reacting as soon as possible. Thus, the motor should have a faster time response with lower electrical time constant, T e and mechanical time constant, T m . However, there are few literatures that reported the time response for a double stator topology. The time response relates to various constant parameters of the motor. It is known that double stator has high torque density which can be implemented …for other applications in the future. For this research, various DSPM BLDC motors had been redeveloped. Finite Element Method (FEM) was used to simulate the characteristics of DSPM BLDC motor that considered the presence of the analytically calculated T e and T m . The results show that the Double Stator Slotted Rotor Permanent Magnet Brushless DC Motor (DSPM-SR) had good performance such as highest back emf, torque and good time response. A prototype of DSPM-SR had been manufactured and measured. The percentage differences between Analytical-FEM and Analytical-Mea for T e and T m were 4.2% and 9.1%, respectively. As a conclusion, this paper reveals the constants that could affect the performance of double stator topology. Show more

Keywords: Double stator, electrical time constant, mechanical time constant

DOI: 10.3233/JAE-190126

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

Authors: Zhou, Hongliang | Zhao, Wu | Zhang, Huiduan | Wang, Yanqin | Wu, Xuefeng | Sun, Zhijia

Article Type: Research Article

Abstract: Magnetorheological fluid (MRF) sealing technology has gained more and more attention in civil engineering, safety engineering, manufacturing, life science, aviation and so on, owing to its great pressure bearing capacity due to the viscous stress and controllable yield stress of MRF under external magnetic field. Even if overpressure occurs, magnetorheological seal (MRS) can restore the serviceability automatically with the help of magnetic field when pressure difference drops back. To have a deep understanding of magnetorheological sealing technique, the paper begins with an introduction of the basic features of MRF and relevant applications of MRS. Then several basic design issues of MRS structure are …introduced. Furthermore, main factors influencing MRS performance are discussed on how to increase the pressure drop of MRS structure. In the end, modeling techniques of MRS structure are provided according to Bingham plastic model, Bi-viscous model, Herschel–Bulkley model and Herschel–Bulkley model with preyield viscosity, respectively, for calculating yield stress of MRF and pressure drop of MRS structure. Hopefully, this review can be regarded as a useful complement to other reviews on MRF technology and applications. Show more

Keywords: Magnetorheological seal, magnetorheological fluid, structure, performance, modeling

DOI: 10.3233/JAE-190082

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

Authors: Iwamoto, Yuhiro | Nakasumi, Hayaki | Ido, Yasushi | Yamaguchi, Hiroshi

Article Type: Research Article

Abstract: Mn-Zn ferrite-based magnetic fluid is temperature-sensitive. Because of the low Curie temperature of Mn-Zn ferrite particles, magnetization is dramatically attenuated as the temperature rises. This temperature-dependent magnetization can be used to transport heat by magnetically driving a fluid via the application of a non-uniform magnetic field and heat. A potential application of this scheme is long-distance heat transport without the use of mechanical pumps. In the present work, a miniaturized magnetically-driven heat transport device with an inner diameter of 𝜙1.54 mm and a flow path length of 1,500 to 6,000 mm was fabricated. The influence of flow path length on the flow …rate induced by the magnetic body force was investigated experimentally and theoretically. Although the flow rate decreased with increasing flow path length due to friction loss, the driving pressure increased with rising heater temperature because of the temperature-dependent magnetization. The influence of flow path length on the driving pressure is relatively insignificant. An increase in the flow path length leads to effects that both attenuate and enhance the driving pressure. Substantial long-distance (6,000 mm) heat transport was realized by applying a non-uniform magnetic field and heat. Show more

Keywords: Magnetic nanofluid, heat transfer, magnetic fluid, temperature-dependent magnetization, energy conversion

DOI: 10.3233/JAE-190033

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

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: 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: Jiang, Jinbo | Yang, Linsen | Yang, Wen | Su, Yi | Liu, Chang | Qiu, Li | Chen, Long | Yu, Kun

Article Type: Research Article

Abstract: Coil inductance calculation is one of the difficulties in Tesla transformer design. The estimation formulas of the conical winding Tesla transformers with different structures are derived by the simplified equivalent of magnetic circuits, and the estimation results are quite different and inaccuracy. This paper provides an energy method based on the FEM (finite element method) to calculate the coil inductance for a double-core conical winding Tesla transformer. A two-dimensional FEM simulation model is established, the magnetic flux density and flux lines distribution have been analysis. And the primary and secondary inductances of the transformer are calculated. Compared the estimation formula …results with the FEM results, the results show that the error difference calculated by the formula estimation is about 3.61%, and the FEM error difference is about 0.4%. The calculation results of FEM are more accurate and convenient, and this method can provide reference for the design of conical winding Tesla transformers. Show more

Keywords: Tesla transformer, conical winding, inductance calculation, magnetic field distribution

DOI: 10.3233/JAE-190089

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