International Journal of Applied Electromagnetics and Mechanics - Volume 51, issue 2

Authors: Cheng, Xin | Chen, Qiang | Zeng, Hongyong | Wang, Xiaoguang | Zhou, Rouguang

Article Type: Research Article

Abstract: Targeting at the radial magnetic bearings of loosely-coupled redundant supporting structure, we classify the failure conditions of electromagnetic coil or power amplifier, and propose the reconfiguration rules for different failure conditions. Selection and configuration methods of redundant supporting structure are described towards the failure characteristics. With the restriction of minimum compensation current, the flux compensation strategy within one pole pair and the magnetic force compensation strategy between adjacent magnetic poles are combined to compensate the loss of electromagnetic force in different failure conditions, which realizes the reconfiguration of the residual supporting structures. The current distribution according to variable electromagnetic force …output after the reconfiguration has been discussed under specific fault conditions and current safety factor of the coils. The influence of the current safety factor to the supporting ability of radial magnetic bearings has been analyzed. The application proves the effectiveness of the reconfiguration rules discussed. Show more

Keywords: Loosely-coupled, magnetic bearings, redundant supporting, reconfiguration

DOI: 10.3233/JAE-150103

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 91-106, 2016

Authors: Tang, Enling | Wang, Hongliang | Xia, Jin | Wang, Meng | Li, Zheng | Zhang, Lijiao | Xiang, Shenghai | Liu, Shuhua | He, Liping | Yuan, Jianfei | Xu, Mingyang | Zhang, Shuang

Article Type: Research Article

Abstract: The purpose of the paper is to investigate the discharge characteristics of plasma generated by a projectile high-velocity impact solar array with 2A12 aluminum substrate structures at the incidence angles of 30°, 45° and 60°, respectively. Three sets of experiments were performed to impact solar array by taking advantage of discharge measurement system established and two-stage light gas gun loading system. Experimental results showed that the second discharge phenomenon did happen in the solar array at the given experimental conditions, and the discharge current peak and time interval between the primary discharge and the second discharge are the biggest at …the projectile incidence angle of 45° in the conditions of the near impact velocity and the different projectile incidence angles. Show more

Keywords: High-velocity impact, projectile incidence angles, plasma; discharge current, discharge voltage

DOI: 10.3233/JAE-150119

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 107-117, 2016

Authors: Chen, Fangyuan | Chen, Xing | Warning, Alexander | Zhu, Huacheng

Article Type: Research Article

Abstract: This research presents a novel designed cavity system for improving microwave heating efficiency. Microwave heating at 2.45 GHz with monopole antennas in a cavity is compared with the conventional magnetron heating on a tylose block. The model for both heating methods was first validated versus experimental results and showed excellent agreement. The antenna heating in a cavity significantly improved the heating rate and uniformity in the tylose sample. The cavity heating method exhibited nearly twice the efficiency as sample sizes increased. The cavity design improves the microwave absorption and final temperature uniformity substantially over the traditional microwave oven. Notably within …the first 60 seconds, the non-uniformity in temperature distribution begins to decrease in the cavity while the magnetron method still shows increasing temperature non-uniformity. The novel use of antennas in a cavity demonstrates the potential for a controllable and selectable microwave heating system that improves power efficiency, heating rate, and temperature uniformity over conventional microwave heating. Show more

Keywords: Electromagnetics, scattering parameter, microwave heating, antenna

DOI: 10.3233/JAE-150123

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 119-129, 2016

Authors: Rodriguez, Elkin | Sotelo, Guilherme G. | de Oliveira, Janaína G. | Santiago, Juan de | Rossander, Morgan | Stephan, Richard M.

Article Type: Research Article

Abstract: This paper presents simulations and experimental results for two types of Passive Permanent Magnet Bearings. The bearing system under investigation consists of two permanent magnet rings opposing to each other in two different configurations. The influence of parameters, such as thickness and radius of permanent magnets, in the force is presented through FEM calculations. Two setups of passive magnetic bearings have been built. Static measurements of radial and axial forces are reported and results compared with simulations. Also, dynamic tests show the behavior of the bearing and the magnitudes of force in the foothold. The results are presented to …show trends in the parameters, so the conclusions are applicable for other sizes and applications. As an example, the application as a top bearing for a 12 kW vertical axis wind turbine is considered. Show more

Keywords: Permanent magnetic bearing, finite element method, vertical axis bearing

DOI: 10.3233/JAE-150162

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 131-149, 2016

Authors: Sun, Xiaodong | Su, Bokai | Chen, Long | Yang, Zebin | Chen, Jianfeng | Zhang, Weiyu

Article Type: Research Article

Abstract: Considering the nonlinear magnetization characteristic of bearingless permanent magnet synchronous motors (BPMSMs), this paper describes a novel nonlinear model of the flux linkage for BPMSMs using adaptive weighted (AW) least square support vector machine (AW-LSSVM) regression algorithm. The inputs of the AW-LSSVM are the rotor angle, and torque winding current and suspension force winding current, and the output of the AW-LSSVM is the flux linkage of the BPMSM. Firstly, the LSSVM regression algorithm is used to build the model according to the sample data and obtain the fitting errors of the sample data. Thus, the initial error weights can be …calculated on the basis of the fitting errors. And then, the lever weights can be defined based on the space distribution of the sample data. Secondly, according to the error weights and lever weights, the sample weights can be obtained adaptively by the proposed weight value iterative scheme. Finally, the relation between inputs and output is trained and the accuracy AW-LSSVM model of flux linkage can be gained. To compare the property of the proposed flux linkage model, the AW-LSSVM and the LSSVM are employed to build the flux linkage model. The simulation results indicate that by using the proposed AW-LSSVM regression algorithm, the influence of the unavoidable outliers on the model property can be effectively eliminated and the superior performance in high precision, strong robustness and quick convergence can also be obtained. Show more

Keywords: Bearingless permanent magnet synchronous motor, nonlinear model, least squares support vector machine, outlier, weighted

DOI: 10.3233/JAE-150165

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 151-159, 2016

Authors: Di Barba, Paolo | Dughiero, Fabrizio | Forzan, Michele | Sieni, Elisabetta

Article Type: Research Article

Abstract: The paper proposes a new strategy to improve the performance of a standard non-dominated sorting algorithm (NSGA) in approximating the Pareto-optimal solutions of a multi-objective problem by introducing new individuals in the population miming the effect of migrations. The design optimization of a power inductor, synthesizing a uniform magnetic field for magneto-fluid hyperthermia applications, is considered as a case study to assess the performance of the migration-modified NSGA algorithm.

Keywords: Multiobjective optimization, genetic algorithm, Pareto optimality, magnetic field, finite-element analysis

DOI: 10.3233/JAE-150171

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 161-172, 2016

Authors: Wang, Zhi-Heng | Wan, Min | Li, Xiao-Jiang

Article Type: Research Article

Abstract: Electromagnetic railgun temperature field characteristics are important basis for rail design and thermal management. This paper carries out numerical modeling of electromagnetic railgun rail temperature field and studies the temperature field characteristics during and after launch of armature. Firstly, the thermodynamics environment of rails during and after armature launch is analyzed; Then, on the basis of rail conducting contact heat model and rail 3D finite element model we have built, the rail temperature field is simulated by finite element software ANSYS. The temperature field of rail at each moment is obtained. The research results show that: The maximal temperature rise …of rail is near the armature initial position; the rail temperature rise gradually decreases from the armature initial position to the muzzle; under the condition of parameters setting in this paper, the temperature rise of each shot near the armature initial position is approximately 8.945°C. Show more

Keywords: Electromagnetic railgun, Finite Element Method (FEM), rails, sliding electrical contact, contact heat, temperature field

DOI: 10.3233/JAE-150174

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 173-183, 2016

Authors: Yan, Wei | Tang, Qiang | Wang, Enrong

Article Type: Research Article

Abstract: The magneto-rheological damper (MRD) has been widely explored in the study of vibration suppression for vehicle suspension and constructional systems, which includes strong nonlinearities arisen from the semi-active control strategy, road surface shock excitations, high-frequency devices in control circuit. Due to the displacement vibration and semi-active control strategy, radiated emission are produced through the cable and excitation coil based on the semi-active control signal. To solve the problem, the radiated emission mechanism and models are proposed and analyzed. Moreover, a novel smoothing algorithm is designed to mitigate the above radiated emission. The simulation and experiment results show that radiated emission …can be suppressed 2-4 dBμ V/m by employing the present smoothing algorithm and comply with EN 55022, which will play an important role in future application study for the electromagnetic interference reduction of intelligent vehicle suspension design with MRDs. Show more

Keywords: Magneto-rheological damper, electromagnetic interference, radiated emission, semi-active control strategy, noise reduction

DOI: 10.3233/JAE-160004

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 185-198, 2016

Authors: Zhang, Chun | Lan, Junqing | Hong, Tao | Gulati, Tushar | Zhu, Huacheng | Yang, Yang | Huang, Kama

Article Type: Research Article

Abstract: A comprehensive physics-based model is developed to understand and explain the process of continuous production of biodiesel via the application of microwaves. Microwave assisted biodiesel production is a complex interplay of electromagnetics, reaction between different components and heat and mass transfer in a tube for continuous manufacturing. The multiphysics model is based on a single mode cavity operating at 2450 MHz. Material properties required for multiphysics modeling are assumed as bivariate functions of reaction solution's component and temperature in this work. An elaborate experimental system was developed to validate the multiphysics model through temperature measurements carried out for different initial …velocities of the reacting components. Excellent agreement was found between experimental values and model predictions with a maximum relative error of 0.908%. The model developed is elaborate from the point of view of physics which can explain the process of microwave-assisted production of biodiesel and it's very important for optimize the process before scaling up. Also, due to fluid flow, presence of hot spots and thermal runaway caused by the short penetration depth of the microwaves and relative long term microwave heating can be done away with especially for large scale. Show more

Keywords: Multiphysics calculation, continuous process, microwave assisted, biodiesel

DOI: 10.3233/JAE-160007

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 51, no. 2, pp. 199-213, 2016