• Title/Summary/Keyword: Maxwell stress tensor

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A Study on a Novel Method for Electromagnetic Force Computation based on Continuum Design Sensitivity Analysis (연속체 설계 민감도해석을 이용한 새로운 전자기력 계산방법에 관한 연구)

  • Kim Dong-Hun
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.6
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    • pp.287-293
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    • 2005
  • Equations have been derived for computing electromagnetic forces by using the Continuum Design Sensitivity Analysis based on the Continuum Mechanics and the Virtual Work Principle. The resultant expressions have similar terms relating to the Korteweg-Holmholz force density, Maxwell Stress Tensor and Magnetic Charge Method but numerical implementation of the proposed scheme leads to efficient calculation and improved accuracy. In addition, the method can be easily applied to computing the magnetic force distribution as well as the global force. Results show the aforementioned advantages in comparison with the conventional methods.

Finite Element Analysis of Electromechanical Field of a Spindle Motor in a Computer Hard Disk Drive Considering Speed Control Using PWM and Mechanical Flexibility (PWM에 의한 속도 제어와 유연 구조를 고려한 컴퓨터 하드디스크 드라이브용 스핀들 모터의 기전 연성 유한 요소 해석)

  • Jang, Jeong-Hwan;Jang, Geon-Hui
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.9
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    • pp.499-508
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    • 2002
  • This paper presents a finite element analysis of the electromechanical field in the spindle motor of a computer hard disk drive considering the speed control and mechanical flexibility. The driving circuit equation is modified by considering the switching action of PWM inverter, and is coupled with the Maxwell equation to obtain the nonlinear time-stepping finite element equation for the analysis of magnetic field. Magnetic force and torque are calculated by the Maxwell stress tensor. Mechanical motion of a rotor is determined by a time-stopping finite element method considering the flexibility of shaft, rotor and bearing. Both magnetic and mechanical finite element equations are combined in the closed loop to control the speed using PWM. Simulation results are verified by the experiments, and they are in food agreement with the experimental results.

A Study on the Driving Principles of a Novel Non-contact Surface Actuator Using Combination of Magnetic Force (비접촉 평면 구동기의 자기력 조합 방식 구동 원리)

  • Jung, Kwang-Suk;Baek, Yoon-Su
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.3
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    • pp.115-121
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    • 2001
  • In micro automation technology, the concurrent realization of a high resolution and a large operating rage has been achieved by a dual actuator, usually called by piggy-back system, conventionally. But, because of its manufacturing cost, the complexity of control, and the limit of overall bandwidth, the contract-free and single servo actuators have been suggested with specific applications. In this paper, we suggest a novel non-contact surface actuator suing combination of the Lorentz force and the magnetized force, and discuss the actuating principles including an analytical approach. Differently from the existing planar system, an operating range of the suggested system can be expanded by an additional attachment of active elements. Therefore, it is estimated to be suitable for the next-generation moving system.

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Electromechanical Simulation of Cellulose Based Biomimetic Electro-Active Paper (생체모방 종이작동기(electro-active paper)의 전기기계적인 구동 시뮬레이션)

  • Jang, Sang-Dong;Kim, Jae-Hwan;Kim, Heung-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.12
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    • pp.1179-1183
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    • 2007
  • Electro-Active paper(EAPap) is a new smart material that has a potential to be used in biomimetic actuator and sensor. It is made by cellulose that is abundant material in nature. EAPap is fascinating with its biodegradability, lightweight, large displacement, high mechanical strength and low actuation voltage. Actuating mechanism of EAPap is known to be the combined effects of ion migration and piezoelectricity. However, the electromechanical actuation mechanisms are not yet to be established. This paper presents the modeling of the actuation behavior of water infused cellulose samples and their composite dielectric constants calculated by Maxwell-Wagner theory. Electro-mechanical forces were calculated using Maxwell stress tensor method. Bending deflection was evaluated from simple beam model and compared with experimental observation, and which result in good correlation with each other.

A study of normal force and its effect in a SPMPM with Halbach array (Halbach 배열 영구자석형 Planar Motor의 수직적 해석 및 영향)

  • Huang, Rui;Zhou, Jianpei;Han, Kwang-Kyu;Kim, Gyu-Tak
    • Proceedings of the KIEE Conference
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    • pp.86-88
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    • 2006
  • This paper presents normal force analysis and its minimization of synchronous permanent magnet planar motor(SPMPM) with Halbach array. Firstly, the experimental error of thrust is investigated and it is caused by the friction force generated by normal force. Then normal force Is analyzed by Maxwell stress tensor. At last, the normal force is minimized by using genetic algorithm and it is decreased from 672.83[N] to 144.24[N] remarkably.

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Body Force Distribution in Permanent Magnet Motors (영구자석 전동기에서의 체적력 분포 관찰)

  • Choi, Hong-Soon;Kim, Young-Sun;Park, Il-Han
    • Proceedings of the KIEE Conference
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    • pp.659-660
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    • 2006
  • 전기기기에서의 전자기력 계산은 기기의 성능뿐 아니라 기계적 변형, 진동을 예측하는 주요 파라미터이다. 지금까지는 Maxwell stress tensor법이나 자하법, 가상변위법등에 의해 전체 전자기력 또는 토크를 계산하여 왔으나, 이 방법들은 모두 분포 전자기력을 계산할 수 없었다. 본 논문에서는 기기 내부의 체적 전자기력분포를 계산하는 방법을 제시하고, 그 예로써 영구자석형 전동기의 전자기력 분포를 보여준다. 체적력의 계산은 저자에 의해 제안 된 가상공극법에 기반하여 구현할 수 있다.

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Electromechanical Simulation of Cellulose Based Biomimetic Electro-Active Paper (생체모방종이작동기(Electro-Active Paper)의 전기기계적인 구동 시뮬레이션)

  • Jang, Sang-Dong;Kim, Heung-Soo;Kim, Jae-Hwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.73-76
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    • 2007
  • Electro-Active paper (EAPap) is a new smart material that has a potential to be used in biomimetic actuator and sensor. It is made by cellulose that is abundant material in nature. EAPap is fascinating with its biodegradability, lightweight, large displacement, high mechanical strength and low actuation voltage. Actuating mechanism of EAPap is known to be the combined effects of ion migration and piezoelectricity. However, the electromechanical actuation mechanisms are not yet to be established. This paper presents the modeling of the actuation behavior of water infused cellulose samples and their composite dielectric constants calculated by Maxwell-Wagner theory. Electro-mechanical forces were calculated using Maxwell stress tensor method. Bending deflection was evaluated from simple beam model and compared with experimental observation, which result good correlation with each other.

  • PDF

Analysis of Radial Force Density as a Vibration Source in Brushless DC Motor Using 3D Equivalent Magnetic Circuit Network Method (3차원 등가자기회로망법을 이용한 Brushless DC 모터의 진동원으로서의 Radial Force Density 해석)

  • Chun, Y.D.;Hur, J.;Yoon, S.B.;Hong, J.P.;Hyun, D.S.
    • Proceedings of the KIEE Conference
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    • pp.171-173
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    • 1997
  • This paper presents analysis of the radial force density in brushless DC motor of which distribution is not uniform in the axial direction. The analysis considering 3D shape of teeth and overhang is not only important but essential to calculate the radial force density that acts on the teeth of stator, because it is frequent source of vibration and changes at the end of teeth. For the analysis, a new 3D equivalent magnetic circuit network method taking into account movement of the rotor without remesh is proposed. The radial force density is calculated by Maxwell stress tensor and analyzed by discrete Fourier transform.

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Electromagnetic Force Density Analysis of Magnetic System (자기시스템의 전자력 밀도 해석)

  • Lee, Se-Hee;Choi, Myung-Jun;Kim, Chang-Wook;Park, Il-Han
    • Proceedings of the KIEE Conference
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    • pp.201-203
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    • 1997
  • As electromagnetic systems have the complexity and high performance, they should be designed to take into account the vibration, noise and strain of mechanical aspect as well as electrical problems. Until now, mechanical approaches have been tried to analyze the subject, but it is difficult to figure out the matter in mechanical consideration. Because they are mainly related to electromagnetic phenomena. This paper deals with the theories and numerical formulations of magnetic force density. Several methods are applied to an actuator and DC machine model to calculate magnetic force density. These results are compared with the total force obtained by maxwell stress tensor and virtual work principle.

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Study on the Characteristic of Ld, LQ Parameter for Interior Permanent Magnet Synchronous Motor in different barrier width (배리어 길이에 따른 매입형 영구자석 동기전동기의 Ld, Lq 파라미터 특성에 관한 연구)

  • Jang, Ik-Sang;Kim, Seung-Joo;Jin, Chang-Sung;Kim, Ki-Chan;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.3
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    • pp.496-501
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    • 2009
  • Interior Permanent Magnet Synchronous Motor (IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux ${\Psi}_a$ and d-axis and q-axis inductances have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, the influence of barrier width on the ${\Psi}_a$ and $L_d$, $L_q$ is calculated by FEM analysis. Predictions are validated by comparison the average torques, using Maxwell Stress Tensor method.