International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 1-2

Authors: Xue, Xiaomin | Sun, Qing | Zhang, Ling | Wu, Xiaohong | Zhang, Lei

Article Type: Research Article

Abstract: Experimental study of the MR damper which is designed and made in our laboratory is introduced in this paper. The experimental results indicate that the mechanical behaviour of the MR damper displays remarkably nonlinear hysteretic characteristics. In order to characterize this nonlinear system, the present study sets out to propose a simplified Bouc-Wen model and then adopt genetic algorithm to identify its parameters. The experimental data of the MR damper responses verify that the proposed approaches …are capable of efficient computations and accurate parameter estimation. Also suggested are the implications of the present study on other novel smart dampers. Show more

Keywords: MR damper, Bouc-Wen model, parameter identification, sensitivity analysis, genetic algorithm

DOI: 10.3233/JAE-2010-1111

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 175-181, 2010

Authors: Woo, Kyungil | Park, Hanseok | Cho, Yunhyun | Kim, Byungtaek | Kim, Daekyong

Article Type: Research Article

Abstract: This paper focuses on the improvement of the torque characteristics of the outer rotor direct drive permanent magnet wind generator that is a radial flux machine with output power of low speed and high torque, 3[kW] 90[rpm] by FEM and optimization. The optimization technique is used to find out a design solution through the comparison of cogging torques according to the shape variation such as the open slot width and the pole arc ratio. In this …technique the problem is to minimize the objective function. The automatic process that includes the automatic ACAD file drawing and mesh generation with regard to the shape variation is also used. The revised generator is obtained from a preliminary model. The cogging torque characteristics of the revised model and the preliminary model and the dynamic characteristics are analyzed. From the simulation results, it is shown that the cogging torque characteristic of the revised model is better than that of the preliminary one. The prototype was manufactured and the simulation result such as induced voltage is agrees with that of the experimental one. Show more

Keywords: Cogging torque, FEM, objective function, optimization, permanent magnet wind generator

DOI: 10.3233/JAE-2010-1112

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 183-190, 2010

Authors: Wang, Jianmin | Jing, Chongyou | Fan, Yana | Liu, Lanrong | Du, Yong | Zhang, Junjie | Jiao, Cuiping | Cheng, Zhiguang

Article Type: Research Article

Abstract: The simplified 3D FEM model coupling with the equivalent electric-circuit (EEC) is well established for a phase-shifting rectifier transformer (PSRT). The 3D stray fields, the parallel branch currents and the short-circuit impedances are calculated by the field-circuit coupling method (FCCM). The validity of the proposed analysis method is verified based on real product, which proved to be more efficient for the design of the PSRT.

Keywords: PSRT, stray fields, short-circuit impedance, FCCM

DOI: 10.3233/JAE-2010-1113

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 191-196, 2010

Authors: Woo, Kyungil | Rhyu, Sehyun

Article Type: Research Article

Abstract: This paper studies on the fault analysis of 3-phase cage induction motor with the mixed fault of the static eccentricity and the broken rotor bars at steady state. A mathematical fault model is presented by the coupled magnetic circuit approach. The calculation of winding inductances is derived by means of a winding function theory. The stator current and the torque are obtained by means of the coupled magnetic circuit method and Park's transformation. The characteristics of …single fault and mixed fault are analyzed. From the simulation results it is shown that there is its own peculiar frequency component obtained by the spectrum analysis of the stator current in the case of a single fault. But in the case of mixed fault, there is a mutual effect between two faults. From the comparison with FEM results, it is shown that the proposed approach can be simulated to diagnose faults in 3-phase cage induction motor. Show more

Keywords: Broken rotor bars, coupled magnetic circuit, static eccentricity, winding function theory

DOI: 10.3233/JAE-2010-1114

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 197-205, 2010

Authors: Yang, Baokun | Luo, Jinglin | Dong, Longlei

Article Type: Research Article

Abstract: This paper presents an optimized design of a magneto-rheological damper with finite element analysis. The MR damper is a new type one compared with the traditional type, which is called the parallel disks valve mode. The effects of magnetic field formation mechanism and MR effect formation mechanism on the MR parallel disks valve performance are investigated. Analytical results of the optimized design of the MR damper with different structural parameters and different materials indicated that the …simulation values by the finite element method are very close to the measured values and also verifies the reliability of the simulation. Show more

Keywords: Magneto rheological damper, magnetic circuit design, fem, optimum design

DOI: 10.3233/JAE-2010-1115

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 207-216, 2010

Authors: Tanaka, Roberto Yuji | Passaro, Angelo | Abe, Nancy Mieko | Vieira, Gustavo Soares | Stephany, Stephan

Article Type: Research Article

Abstract: Self-consistent calculations of multi-quantum well semiconductor structures based on a Finite-Element Method are presented. The self-consistent calculation is specially needed when wells of different width are present in the structure, generating a larger charge separation and affecting significantly the tunneling conditions. The object-oriented computer code used was implemented using a finite-element class library developed and used in previous works. Results for an asymmetric heterostructure with a larger well and contact layers are …also presented. Show more

Keywords: Quantum well, finite element methods, nanotechnology, self-consistency

DOI: 10.3233/JAE-2010-1116

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 217-223, 2010

Authors: Zhang, Guogang | Chen, Wei | Ke, Chunjun | Zheng, Peng | Geng, Yingsan

Article Type: Research Article

Abstract: Dynamic characteristics reflect the real situation of an AC contactor and are very important to the optimum design of AC contactors. A simulation model of intelligent AC contactor has been established using the ADAMS software with developing a user subroutine in which the iterated Runge-Kutta method is adopt to solve a set of differential equations that describe the coupling of circuit, electromagnetic and mechanical systems. Because of reusing the analysis results obtained from the simulation of …static characteristics accomplished by the ANSYS software, the simulation model runs more efficiently. In addition, by using the ADAMS/solver in the batch mode, an optimization library have been integrated with the ADAMS software and successfully used to seek the optimal control parameters to minimize the contact bounces and core bounces. The simulation results show that the intelligent AC contactor with PWM control can effectively reduce the bounces and energy consumption. Show more

Keywords: AC contactor, dynamic characteristics, simulation and optimization

DOI: 10.3233/JAE-2010-1117

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 225-233, 2010

Authors: Jang, Jin-Soek | Kim, Ho-Hyun | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper proposes a method to reduce the torque ripple of a square wave voltage-driven BLDC motor. First of all, this paper reviews a previous voltage control method to reduce torque ripple, and shows that cogging torque component still remains. Then this paper proposes an improved voltage control method to offset cogging torque. To verify the proposed method, FE-analysis is performed for a test BLDC motor and it is shown that torque ripple is considerably reduced …comparing with a previous control. Show more

Keywords: BLDC motor, cogging torque, commutation, torque ripple, voltage control method

DOI: 10.3233/JAE-2010-1118

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 235-241, 2010

Authors: Cao, Ronggang | Fang, Zhang | Zou, Jun | Yuan, Jiansheng

Article Type: Research Article

Abstract: Electromagnetic forces of ferromagnetic materials consist of attractive and repulsive components, which can be introduced from the Lorentz force formula and the Kelvin force formula. In harmonic fields, the attractive and the repulsive forces both have DC and AC components and they cancel out with each other to reduce the total average force. The contributions or influences of the frequency, magnetic permeability and electric conductivity of the material to attractive and repulsive forces in time-varying fields …are analyzed and simulated by the numerical experiments using FEM methods. Results show that the total time average electromagnetic forces can be reduced greatly, even to zero in certain states, which is useful to control the vibration problem. Show more

Keywords: Electromagnetic forces, ferromagnetic materials, time-varying electromagnetic fields

DOI: 10.3233/JAE-2010-1119

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 243-249, 2010

Authors: Choi, Myoung-Hyun | Song, Jeong-Hyun | Woo, Kyungil | Kim, Byung-Taek

Article Type: Research Article

Abstract: In this paper a design condition for magnetically balanced operation in a single phase induction motor is presented in analytic forms. In addition a condition for minimal stator copper is deduced under condition that the balanced operation is satisfied. Using these conditions, an optimal induction motor is designed by a proper optimization algorithm, and its loss characteristics are investigated. From the results, the validity of the proposed method is verified.

Keywords: Balanced operation, minimal stator copper, optimization algorithm

DOI: 10.3233/JAE-2010-1120

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 251-258, 2010