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

Authors: Sun, Xiaodong | Cai, Feng | Tian, Xiang | Wu, Minkai

Article Type: Research Article

Abstract: Permanent magnet synchronous hub motors (PMSHMs) have been gradually introduced into the applications of electric vehicles. On this basis, the six-phase motor has the characteristics of high reliability, high power density and low torque ripple. And its fault tolerance is a large advantage compared with the three-phase motor. The multi-phase permanent magnet synchronous motor is redundant due to the number of phases. When the motor fails, it does not have to stop running, merely adjust its control mode and enter the fault-tolerant compensation control algorithm to resume the operation of the system. The FCS-MPC algorithm can replace the cascade structure …in the traditional control and eliminate the modulation module. This makes it have good steady-state performance. The speed response is also improved. It can be combined with multiple control objectives with strong flexibility by simply changing the objective function. The prediction model is compensated. Finally, the experimental results show the effectiveness of this method. Show more

Keywords: Six-phase motor, model predictive control (MPC), fault-tolerant, permanent magnet synchronous hub motors (PMSHMs)

DOI: 10.3233/JAE-210033

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-24, 2021

Authors: Ye, Kuan | Zhou, Kai | Zhigang, Ren | Zhang, Ruizhe | Li, Chunsheng | Sun, Hongyu | Huang, Songling

Article Type: Research Article

Abstract: The power transmission tower’s ground electrode defect will affect its normal current dispersion function and threaten the power system’s safe and stable operation and even personal safety. Aiming at the problem that the buried grounding grid is difficult to be detected, this paper proposes a method for identifying the ground electrode defects of transmission towers based on single-side multi-point excited ultrasonic guided waves. The geometric model, ultrasonic excitation model, and physical model are established, and the feasibility of ultrasonic guided wave detection is verified through the simulation and experiment. In actual inspection, it is equally important to determine the specific …location of the defect. Therefore, a multi-point excitation method is proposed to determine the defect’s actual position by combining the ultrasonic guided wave signals at different excitation positions. Besides, the precise quantification of flat steel grounding electrode defects is achieved through the feature extraction-neural network method. Field test results show that, compared with the commercial double-sided excitation transducer, the single-sided excitation transducer proposed in this paper has a lower defect quantization error in defect quantification. The average quantization error is reduced by approximately 76%. Show more

Keywords: Transmission tower, ground electrode, Lamb wave, defect detection, feature extraction-neural network

DOI: 10.3233/JAE-210039

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

Authors: Eldabe, Nabil T. | Abou-zeid, Mohamed Y. | Abosaliem, Adel | Alana, Ahmed | Hegazy, Nada

Article Type: Research Article

Abstract: In this study, the effects of radially varying magnetic field, internal heat generation and mixed convection with thermal radiation on peristaltic motion of a non-Newtonian fluid are investigated. The fluid used is third-grade model. The flow is through the gap between two co-axial vertical tubes under the effect of radially varying magnetic field. The outer tube is flexible with sinusoidal deformations. The problem is modulated mathematically by a system of partial differential equations which describes the equations of momentum, heat transfer and nanoparticles concentration which are simplified by using long wave length and low-Reynolds number assumptions. The closed solutions of …fluid temperature and nanoparticle concentration are obtained, and the solution of velocity is obtained by using the homotopy perturbation method (HPM). The radially varying magnetic field effect on the axial velocity is discussed and it is shown that the increase of magnetic field parameter tends to reduce the fluid flow. Show more

Keywords: Non-Newtonian nanofluid, peristaltic flow, varying magnetic field, heat transfer

DOI: 10.3233/JAE-210001

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

Authors: Wei, Mengfei | Zhang, Chi | Chen, Jinhua

Article Type: Research Article

Abstract: This paper presents a nonlinear iterative magnetic equivalent circuit (MEC) model for a novel counter-rotation dual-rotor axial flux permanent magnet synchronous machine (CRDR-AFPMSM). The proposed machine mainly consists of two rotors with opposite rotation directions, two sets of concentrated windings and a stator core sandwiched in between the two rotors. The model takes into account of the nonlinear characteristics of the saturable permeance in the stator core, and the permeance matrix is updated by an iterative procedure to accurately illustrate its nonlinear feature. The air gap flux density, back electromotive force (EMF) and torque are predicted by the model. Based …on the nonlinear model, the thickness of the stator yoke is determined. All of the results obtained by the proposed model match with finite element analysis (FEA) results closely, thus the validity of the proposed MEC model is verified. Show more

Keywords: Counter-rotation dual-rotor flux permanent magnet synchronous machine (CRDR-AFPMSM), nonlinear magnetic equivalent (MEC), saturable permeance, finite element analysis (FEA)

DOI: 10.3233/JAE-210012

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

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

Article Type: Research Article

Abstract: This paper proposes a novel flux switching claw pole machine (FSCPM) with soft magnetic composite (SMC) cores. The proposed FSCPM holds advantages of the conventional flux switching permanent magnet machine (FSPMM) and claw pole machine (CPM) with SMC cores. As permanent magnets are installed between the stator claw pole teeth, FSCPM has good flux concentrating ability, and the air gap flux density can be significantly improved. The torque coefficient of FSCPM is relatively high due to the applied claw pole teeth and global winding. FSCPM is mechanically robust because there are no windings or PMs on its rotor. Moreover, the …core loss of FSCPM is relatively low for the SMC material has lower core loss at high frequency compared with silicon steels. The topology and operational principle of FSCPM are explained first. Several main dimensions of the machine are optimized to achieve better performance, based on 3D finite element method (FEM). Furthermore, the rotor skewing technology is adopted to reduce the cogging torque and torque ripple. Show more

Keywords: Flux switching claw pole machine (FSCPM), soft magnetic composite (SMC), flux concentrating, cogging torque, torque ripple

DOI: 10.3233/JAE-210009

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

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

Article Type: Research Article

Abstract: This paper proposes a novel permanent magnet assisted synchronous reluctance (PMAREL) machine, the main structure of this machine is quite similar to that of traditional PMAREL machine, and the main difference is that the grain-oriented silicon steel is used to replace some part of the stator teeth. The rolling direction of the grain-oriented silicon steel is along the radial direction of the machine, thus the advantage of higher permeability and higher kneel point in this material can be used to release the flux saturation problem of the traditional non-grain-oriented steel used in the PMAREL machine when the applied current density …is high. Firstly, the structure of both proposed novel and traditional PMAREL machines are optimized and the design parameters are determined. Secondly the electromagnetic and mechanical performance are compared in these two machines which includes the demagnetization analysis, mechanical stress analysis when the rotor at the maximum speed, torque ability, efficiency by using the finite element method (FEM). It can be seen that the problem of stator teeth saturation in the novel PMAREL has been alleviated, and compared with the traditional PMAREL machine, the novel PMAREL has higher efficiency, wider speed range and 7% higher torque ability. Show more

Keywords: Permanent magnet assisted synchronous reluctance (PMAREL) machine, grain-oriented silicon steel, optimization, finite element method (FEM)

DOI: 10.3233/JAE-201619

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2021

Authors: Cheng, Yuhua | Kang, Wenyu | Wang, Gaofeng | Ghovanloo, Maysam | Li, Wenjun

Article Type: Research Article

Abstract: In the inductive wireless power transmission (WPT) designs of consumer electronics and implantable devices, the printed planar coil in standard manufacture is commonly used. Layout optimization of the coils is one of the important ways to make the power transmission system more efficient. Varying the trace width and turn-to-turn spacing together for the coils is proposed to optimize the maximum achievable power transfer efficiency (𝜂max ). An accurate analytical model for the printed square coils is also established as well to speed up the design process. By virtue of this model, an optimal scaling factor of the trace width and …the optimal frequency can be quickly estimated. The proposed model is validated by both the simulations (ANSYS HFSS) and experiments. A WPT link of two planar coils with size of 50 mm × 50 mm × 1 mm, operating at 23 MHz, is optimized by using this methodology. After optimization, the measured 𝜂max of the WPT system is increased from 22.60% to 32.74% at a 100-mm transmission distance. Show more

Keywords: Wireless power transmission, printed planar coil, layout optimization, analytical modelling

DOI: 10.3233/JAE-201641

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

Authors: Gao, Sumei | Ju, Quanyong | Jin, Chaowu

Article Type: Research Article

Abstract: In this paper, a kind of permanent magnet (PM) suspension active mass drive mechanism is proposed, and its structure is designed. It has the advantages of non-contact, almost zero friction, small volume, and so on. Aiming at the active driving mass mechanism of PM suspension, the unidirectional PM suspension system and bi-directional PM suspension system are designed respectively, and their analytical models are established. By analyzing and calculating the magnetic force of the unidirectional and bi-directional PM suspension system, the support coefficient of the suspension system is deduced. After theoretical analysis, the structure is simulated and verified by ANSYS MAXWELL …3D in order to determine the correctness of the analytical calculation of the model. Finally, a test device is made and experiments are carried out in the constant temperature laboratory. The experimental results show that the Nd-Fe-B PMs used in the unidirectional suspension system can provide a maximum force of 260 N, which verify the feasibility of the PM suspension active mass drive system. Show more

Keywords: Permanent magnet (PM), magnetic suspension, AMD, support characteristics

DOI: 10.3233/JAE-201631

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

Authors: Nigam, Padmini | Muduli, Arjuna | Sharma, Sandeep | Pal, Amrindra

Article Type: Research Article

Abstract: In this letter, an efficient and electrically compact cavity-backed self-triplexing antenna using a substrate integrated waveguide (SIW) technique is proposed. The antenna model is nested with an inverted “T”-shaped cavity and convert the rectangular SIW cavity into the two quarter mode (QM) and a half mode cavity (HM) approximately; excited through a coax probe and two micro-strip feed line separately. The proposed model operates at three distinct frequencies at 9.37 GHz, 9.86 GHz, and 10.36 GHz used for X-band wireless and radar communication systems. The self-triplexing feature is obtained with the mode perturbation concept and adequate intrinsic isolation of >31 dB is observed …among three input ports. The proposed antenna possesses a minimum frequency ratio, uni-directional radiation patterns with high gain, and better efficiency. Show more

Keywords: Substrate integrated waveguide (SIW), isolation, self-triplexer, quarter-mode (QM), gain

DOI: 10.3233/JAE-201639

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

Authors: Yang, Xiaolong | Guan, Ying | Li, You | Gao, Shanghan

Article Type: Research Article

Abstract: In order to solve the problem of reciprocating seal for hydraulic cylinder, a new structure of Magnetorheological fluid (MRF) reciprocating seal with increasing width of pole teeth and pole piece was designed. The theoretical analysis of MRF reciprocating seal is carried out. The magnetic field intensity distribution in the sealing gap of MRF reciprocating seal was analyzed by finite element method. According to the pressure capability formula of MRF, the theoretical pressure capability is calculated. The influences of structure parameters such as the number of magnetic sources, sealing gap height, pole teeth length, the ratio of permanent magnet height to …its length, the ratio of pole piece height to shaft radius on the sealing capabilities were studied. The results showed that the pressure capability of MRF reciprocating seal increases with the increase of the number of magnetic sources and with the decrease of the sealing gap height. With the increase of the pole tooth length, the pressure capability of the reciprocating seal increases. With the increase of the ratio of permanent magnet height to its length, the pressure capability of the reciprocating seal increases first and then decreases. With the increase of the ratio of the pole piece height to shaft radius, the pressure capability of the MRF reciprocating seal increases first and then decreases. Show more

Keywords: MRF, reciprocating seal, key parameters, numerical analysis

DOI: 10.3233/JAE-201628

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

Authors: Karaçuha, Kamil | Tabatadze, Vasil | Veliyev, Eldar Ismailovich

Article Type: Research Article

Abstract: In this study, the cylindrical wave diffraction by double strips with different lengths and boundary conditions are investigated. The scattered fields are found by the Numerical-Analytical Approach. The double-strip structure satisfies integral boundary conditions which are the generalization of Dirichlet and Neumann boundary conditions. The electric field, current distribution, and Total Radar Cross Sections are investigated. The results are compared with other methods and previous findings such as the Method of Moments and Physical Optics. The theoretical and numerical analyses indicate that the fractional order, the position of the line source have tremendous effects on the total-field distributions.

Keywords: Electromagnetic diffraction, fractional boundary condition, fractional double strips, integral boundary condition, line source

DOI: 10.3233/JAE-210006

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

Authors: Wang, Jing | Song, Haicheng | Tomizawa, Takuma | Yusa, Noritaka | Ling, Yuanjin

Article Type: Research Article

Abstract: It is still a big challenge to calculate the probability of defect detection for inspecting pits on austenitic stainless steel welding using traditional POD models. Because we determine the decision threshold, the POD curve has a lot of changes as the decision threshold changes, there is no clear reason to insist which threshold is reasonable. This study proposes a new probability of detection (POD) model to quantitatively assess the detection capability of eddy current probes for inspecting pits on austenitic stainless steel welding. The experimental results show that the proposed model is more reasonable than traditional ones. The novel POD …model was employed to analyze three eddy current probes, uniform, TR, plus-point probes on austenitic stainless steel welding. The results reveal that the uniform eddy current probe has the best detection capability for inspecting pits on among the three probes. Show more

Keywords: Eddy current testing, probability of detection, stochastic decision threshold, austenitic stainless steel welding

DOI: 10.3233/JAE-201602

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

Authors: Eldabe, Nabil Tawfik | Moatimid, Galal M. | Abouzeid, Mohamed | El-Shekhipy, Abdelhafeez A. | Abdallah, Naglaa Fawzy

Article Type: Research Article

Abstract: In the current paper, a semi-analytical solution is obtained for the problem of the peristaltic motion of Jeffrey nanofluid with heat transfer inside an asymmetric channel. The influences of variable viscosity, thermal conductivity, Hall currents, Joule heat and viscous dissipation are taken into consideration. The problem is modulated mathematically by a system of non-linear partial deferential equations which describe the fluid velocity, temperature and nanoparticles concentration distributions. This system is simplified by considering long wavelength of the peristaltic wave and low Reynolds number. It is solved by using the multi-step deferential transform method to obtain the velocity, temperature and nanoparticles …concentration distributions, pressure rise and pressure gradient. These solutions are obtained as functions of the physical parameters of the problem. Tables and figures are discussed to see the effects of these parameters. It is found that the thermal conductivity parameter causes an increase in the pressure gradient, meanwhile it reduces the pressure rise. Furthermore, it is noticed that the behavior of Brownian and thermophoresis parameters on nanoparticles concentration field are quite reverse. Show more

Keywords: Peristaltic flow, Jeffrey nanofluid, Hall currents, Joule heating, Mathematica 11

DOI: 10.3233/JAE-201626

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

Authors: Swiatkowski, Michal | Witczak, Pawel

Article Type: Research Article

Abstract: The aim of this paper is to present the impact of the leakage flux on magnetic shunts and tank walls of power transformers from vibrational point of view. The experimental studies of the large power transformers show that tank vibrations and the resulting acoustic emission at load condition are significantly higher than at no-load condition. The paper presents 3D finite elements model in electromagnetic domain used for the analysis of magnetic forces applied to shunts at rated short circuit state which are the origin of tank vibration. The main finding of the work is that forces equivalent to the magnetostriction …deformation of the shunt interior are comparable with magnetic forces resulting from the stray field and applied to the shunts’ surface. Show more

Keywords: Power transformer, magnetic shielding, magnetic flux leakage, magnetic and magnetostriction analysis

DOI: 10.3233/JAE-201622

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

Authors: Wang, Geng | Gao, Renjing | Wang, Qi | Liu, Shutian

Article Type: Research Article

Abstract: Electromagnetic linear actuators (ELAs) may be confronted with unsatisfactory performance when subjected to overheating. Therefore, it is significant to clarify its thermal characteristics and design the thermal performance requirements. A thermal analysis method based on multiphysics coupling model was presented, which uses the non-simplified loss distribution as the heat source to calculate the temperature field, adjusts the material properties by temperature, and considers the interaction between motion (including impact) and loss. More importantly, an improved universal equivalent winding to satisfy the condition of real compact concentrated winding was developed. Finally, the validity of this approach was verified through the experiment, …and the regularity of temperature was summarized. The results show that the error of simulation and experiment is less than 6% and the permissible continuous operation frequency is no more than 30 Hz. The approach proposed in this paper can be employed not only to the ELA, but also to the design and analysis a wide range of electromagnetic machines. Show more

Keywords: Electromagnetic linear actuator, equivalent winding, multiphysics coupling model, thermal analysis method

DOI: 10.3233/JAE-201586

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

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: 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: 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