International Journal of Applied Electromagnetics and Mechanics - Volume 67, issue 3

Authors: Xiong, Qi | Song, Xianqi | Yang, Meng | Zhou, Lijun | Li, Zhe | Zhu, Xinhui | Zhi, Li

Article Type: Research Article

Abstract: Magnetic targeted drug delivery systems can improve drug utilization and reduce drug side effects. There are still many difficulties to be overcome in clinical practice. The main problems include providing large enough magnetic capture particles to concentrate drug-loaded magnetic micro-nanoparticles (MNPs) to the lesion site. The existing research focuses on the development of targeted carriers, and the magnet device has not formed a mature research system. Based on the recent development of magnet devices in recent years, this paper proposes the research direction of potential magnet devices. From the dynamic behavior of the particles under the magnetic field, the magnetic …system and the mathematical model design direction of the optimized magnet are developed. This article describes the obstacles encountered in drug targeting in the study of magnet devices and summarizes the potential development of future magnet devices. Show more

Keywords: Magnetic targeted drug delivery system, magnet device, targeted behavior

DOI: 10.3233/JAE-210021

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 261-277, 2021

Authors: Xiong, Zhiqiang | Yao, Jin

Article Type: Research Article

Abstract: A novel squirrel cage eddy current coupling with adjustable radial air gap was presented, which can change the output speed by changing the air gap thickness in radial direction between the copper strips and the permanent magnet. It has the advantages of no axial force in speed regulation and less eccentric force in axisymmetric structure. The 2-D electromagnetic torque model of the rotor was established, and the influence of the air gap thickness on the electromagnetic torque was also studied by finite element method. Further, a novel method to solve the dynamic equation of the eddy current coupling was proposed …based on the effect of air gap thickness and relative speed on torque characteristics, and was applied to the speed regulation performance analysis. In addition, the influence of the relative magnetic permeability of the permanent magnet back yoke and the internal rotor on the speed regulation performance was studied. Show more

Keywords: Radial air gap adjustable, squirrel cage eddy current coupling, electromagnetic torque, speed regulation performance

DOI: 10.3233/JAE-201536

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 279-297, 2021

Authors: Li, Changyun | Yu, Yongjin | Kong, Xu

Article Type: Research Article

Abstract: In this paper, the mechanical properties of nano-silica modified insulating paper under the combined action of mechanical vibration and temperature conditions are studied. Unmodified and nano-silica modified cellulose insulating paper with 2 wt% and 4 wt% were prepared, respectively, and a series of mechanical-thermal synergy experiments were carried out. With the same mechanical stress and temperature, and with the same aging duration of 144 h (6d), the tensile strength of modified insulating paper with 4 wt% nano-silica, increased 0.99 kN/m and 0.55 kN/m, respectively, compared with those of the unmodified and the 2 wt% nano-silica modified insulating paper. The experiments …indicate that the nano-silica modification can effectively improve the mechanical properties of insulating paper. In this work, the modified mechanism of nano-silica is analyzed from the interface effect of modified polymer and the quantum effect of the modified polymer interface two aspects. It is shown that the interface formed in the modified insulating paper can transfer the mechanical stress acted on the insulating paper and prevent the cracks formed in the aging process of the test sample from further expansion, while the quantum effect discretizes the electron energy level, which can restrict the motion of the molecular chain segment to some extent. The conclusion can be used for reference to improve the performance of insulating paper. Show more

Keywords: Degree of polymerization (DP), mechanical-thermal synergy, nano-silica particle, tensile strength (TS)

DOI: 10.3233/JAE-210027

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 299-312, 2021

Authors: Huangfu, Youpeng | Wang, Shuhong | Yin, Shuli

Article Type: Research Article

Abstract: This paper presents a quantitative prediction model of conducted electromagnetic emissions (EME) for a variable frequency drive (VFD) motor system based on the macro-modeling approach. This model relies on the effective representations of the frequency dependent characteristics of the parasitic behaviors between converter arms and heatsink, of shielded power cable, and of motor windings. The frequency dependent performances between converter arms and heatsink, and of the motor windings are obtained by processing measurement data. Then the vector fitting method (VFM) with passivity enforcement and circuit synthesis method are adopted to obtain the corresponding equivalent circuits. The equivalent circuit implementation of …shielded power cable is achieved by applying a node-to-node admittance functions (NAFs) model, which considers the propagation phenomenon and frequency dependent losses accurately. The conducted EME model is compatible with commonly used transient circuit solvers since it only includes constant circuit elements. The conducted emissions of the VFD system are then evaluated by analyzing the common mode (CM) and differential mode (DM) voltages and currents. Show more

Keywords: Conducted emissions, frequency dependent, macro-modeling, variable frequency drive

DOI: 10.3233/JAE-210036

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 313-325, 2021

Authors: Xu, Yixiang | Di, Chong | Bao, Xiaohua | Xu, Dongying

Article Type: Research Article

Abstract: The torque ripple is affected by both the stator and the rotor magnetic field harmonics. In synchronous reluctance motors (SynRM), there are only rotor permeance harmonics existing on the rotor side for the absence of the rotor windings. Since the asymmetric rotor flux barriers are widely applied in the SynRM rotor, it is difficult to calculate the rotor permeance accurately by the analytical method. In this article, the effects of the rotor permeance harmonics on the air-gap magnetic field are studied by a virtual permanent magnet harmonic machine (VPMHM), which is a finite-element (FE) based magnetostatic analysis model. The air-gap …flux density harmonics produced by the SynRM rotor are extracted from the VPMHM model and used as the intermediate variables for the torque ripple optimization. The proposed method does not need to solve the transient process of motor motion. Hence, the time of the optimization process can be significantly shortened. Finally, a full electric cycle is simulated by dynamic FE simulation, and the torque ripple is proved to be effectively reduced. Show more

Keywords: Synchronous reluctance motors, torque ripple, virtual permanent magnet harmonic machine

DOI: 10.3233/JAE-210068

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 327-338, 2021

Authors: Hu, Guoliang | Qi, Haonan | Chen, Miao | Yu, Lifan | Li, Gang | Zheng, Han

Article Type: Research Article

Abstract: In this paper, a magnetorheological (MR) damper with multiple axial fluid flow channels is developed to solve the conflicts between limitation of size dimension and improvement of damping performance. By setting symmetrical excitation coils at both ends of the MR damper, the effective fluid flow channels of the proposed MR damper are significantly lengthened. In order to investigate the distributions of magnetic flux lines and magnetic flux density of the MR damper, the finite element model of the MR damper is established by using ANSYS software. Moreover, an optimization method combining BP neural network and particle swarm optimization (PSO) is …proposed to improve the magnetic field utilization of the designed damper, and the damping performances of initial and optimal MR dampers are also experimentally tested. The test results show that the output damping force of initial and optimal MR dampers is 3.13 kN and 5.98 kN respectively under the applied current of 1.8 A, increasing by 91.1%, and the dynamic adjustable range is 11.5 and 16.1 respectively, increasing by 40.0%. It is found that the damping performance of the proposed MR damper is significantly improved. Show more

Keywords: MR damper, multiple axial fluid flow channels, optimal design, BP neural network, particle swarm optimization

DOI: 10.3233/JAE-210089

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 339-360, 2021

Authors: Xia, Yunyan | Du, Hao | Shao, Yuanliang

Article Type: Research Article

Abstract: This paper aims to propose a method to determine the temperature rise and rated capacity of induction motors under different working systems. A dynamic mathematical model, a 3D temperature field model, and finite element method are used to analyze the electromagnetic loss and transient temperature rise, respectively. The influence of the motor starting process on the temperature rise is taken into account, which resolves the complex loading of transient heat source. The maximum allowable running times for the motor operating with different overloads are determined. The relationship between the motor output power and the allowable running time is obtained, and …it provides a basis to determine the rated capacity of motor under S2 working system. The relationship between the motor output power and the temperature rise under different load duration rates is also obtained and provides reasonable evidence to determine the rated capacity of the motor under S3-working system. Show more

Keywords: Induction motor, finite element method, transient temperature, rated capacity

DOI: 10.3233/JAE-210004

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 361-373, 2021

Authors: Hu, Yongpan | Long, Zhiqiang | Xu, Yunsong | Wang, Zhiqiang

Article Type: Research Article

Abstract: Poor stability of the permanent magnet electrodynamic levitation hinders its application in the maglev field. Therefore, building a control-oriented model to improve its stability is most challenging. However, intractable electromagnetic models leading to an implicit relationship between levitation force and gap, yields a barrier for model-based controller design. To solve the above-mentioned problem, this paper develops a control-oriented model by two stages. Specifically, the first stage is to show an explicit formula of the levitation force with regard to the levitation gap by neglecting end effect; meanwhile the “maximum–minimum rectification” method is put forward to evaluating an accurate levitation force. …The second stage is to bring forth the control-oriented model on basis of the estimated levitation force. Although the paper focus mainly on the development of the control-oriented model, an example of PD controller is provided to verify its validation. Experiment results demonstrate the estimated levitation force is highly consistent with the real one. Simulation results show that the control-oriented model is sufficiently reliable. The research bridges the gap between the physical model and the model-based controller for the electrodynamic levitation with permanent magnet Halbach array. Show more

Keywords: Electrodynamic levitation, Halbach array, control-oriented, levitation force

DOI: 10.3233/JAE-210007

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 67, no. 3, pp. 375-392, 2021