• Title, Summary, Keyword: electromagnetic force

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The effect of external electromagnetic force in GMAW (외부 전자기력을 이용한 가스메탈 아크용접법에 관한 연구)

  • Lee, Seong-Ho;Lee, Jae-Yun;Kim, Jae-Seong;Lee, Bo-Young
    • Proceedings of the KSME Conference
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    • pp.1741-1746
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    • 2003
  • Effects of electromagnetic force which is one of the most important factor of metal transfer that affects bead geometry and microstructure of weld metal in GMAW(gas metal arc welding). In this paper, different ways of external electromagnetic forces were applied on GMAW process and their effects on the welding were studied. On certain conditions, better bead geometry, better influence on the arc and metal transfer mode and higher welding efficiency could be obtained. Experimental methods and their results will be presented.

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Calculation of Electromagnetic Excitation Forces in Double Skewed Motors

  • Bao, Xiaohua;Di, Chong;Zhou, Yang
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.812-821
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    • 2018
  • An electromagnetic excitation force is caused by the air-gap flux density, which greatly influences the noise and vibration of the motor. In many real projects, skewed slot technology is widely used to reduce the harmonic components of the air-gap flux density to reduce the noise and vibration of the motor. However, a skewed slot has several side effects such as a transverse current and axial drifting. Thus, a double skewed slot rotor is selected with the aim of eliminating these side effects. This paper presents the exact structure of the double skewed slot rotor and the mechanism whereby the electromagnetic excitation force can be reduced. A multi-slice method is adopted to model the special structure. Finite element simulation is used to verify the theory.

Topology Optimization of an Electromagnetic Coupler Considering Force Direction (힘의 방향성을 고려한 전자기 커플러의 위상 최적화)

  • Yang, Seung-Jin;Yoo, Jeong-Hoon
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.4
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    • pp.230-235
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    • 2006
  • The machine locking system is an important device for the safety of persons using the machine. In this study, a locking system using electromagnetic fields is proposed to decrease the defects and the cost for repairing and maintenance of the existing locking system using structural mechanism. We analyze the electromagnetic locking system and calculate the generated force considering direction by the finite element method. Also, we set up two design domains for the topology optimization; first domain is optimized to reduce the volume and the other is optimized to maximize the generated force keeping the volume, especially. The optimal design is obtained by integration of the two optimized results. An improved design is obtained by the optimal topology and it is confirmed by comparison with the initial locking system.

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Vibration Analysis for BLDC Motor by Electromagnetic Exciting Force (전자기 가진력에 의한 BLDC 전동기의 진동 특성 해석)

  • Chung, H.J.;Shin, P.S.;Woo, S.H.
    • Proceedings of the KIEE Conference
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    • pp.118-120
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    • 2007
  • This paper deals with the vibration analysis of characteristics for BLDC motor by electromagnetic exciting force. Vibration analysis of electric machine is mainly divided into mechanical and electrical approach. However, it need to execute coupling analysis of mechanical and electrical computation because the vibration sources have relation to each other. Magnetic fields is calculated from Maxwell stress method with electromagnetic finite element method. And magnetic radial force is calculated from previous magnetic fields. With coupled electromagnetic and structure finite element, the vibratory behavior between the phase commutation advancing technique and pulse-width control is investigated in single phase brushless dc motor.

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Prediction of Electromagnetic Repulsion Force and Temperature Rise in Electric Contact Mechanism Using ANSYS (ANSYS를 이용한 전기 접촉 기구의 전자 반발력 분석 및 온도 상승 예측)

  • Park W.J.;Kim K.H.;Ahn K.Y.;Oh I.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.666-669
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    • 2005
  • As computer power increased, the system with complex phenomenon has been analyzed with the help of CAE software which can handle the coupled physics, such as electromagnetic, structure, thermal and fluid physics. To predict the electromagnetic repulsion force and the temperature distribution of an air circuit breaker with electric contact mechanism, ANSYS/EMAG, FLOTRAN can be used. Although some assumptions and simplifications were introduced to simulate the model, results from the computational model were in good agreement with actual measurements obtained from experiments.

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Miniaturization and Optimization of Electromagnetic Actuators for Implantable Hearing Device Based on MEMS Technology (MEMS 기술 기반 이식형 청각 장치용 전자기 엑츄에이터의 소형화 및 최적화)

  • Kim, Min-Kyu;Jung, Yong Sub;Cho, Jin-Ho
    • Journal of Sensor Science and Technology
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    • v.27 no.2
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    • pp.99-104
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    • 2018
  • A micro electromagnetic actuator with high vibration efficiency is proposed for use in an implantable hearing device. The actuator, which can be implanted in the middle ear, consists of membranes based on the stainless steel 304 (SUS-304), and other components. In conventional actuators, in which a thick membrane and a silicone elastomer are used, the size reduction was difficult. In order to miniaturize the size of the actuator, it is necessary to reduce the size of the actuation potion that generates the driving force, resulting in reduction of the electromagnetic force. In this paper, the electromagnetic actuator is further miniaturized by the metal membrane and the vibration amplitude is also optimized. The actuator designed according to the simulation results was fabricated by using micro-electro-mechanical systems (MEMS) technology. In particular, a $20{\mu}m$ thick metal membrane was fabricated using the erosion process, which reduced the length of the actuator by more than $400{\mu}m$. In the experiments, the vibration displacement characteristics of the optimized actuator were above 400 nm within the range of 0.1 to 1 kHz when a current of $1mA_{rms}$ was applied to the coil.

Comparison of Korteweg-Helmholtz Electromagnetic Force Density and Magnetic Charge Force Density in Magnetic Systems (자기시스템의 Korteweg-Helmholtz 전자력 밀도와 자하 전자력 밀도의 비교)

  • Lee, Se-Hui;Choe, Myeong-Jun;Park, Il-Han
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.4
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    • pp.226-232
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    • 2000
  • In magnetic systems, distribution of electromagnetic force density causes mechanical deformation, which results in noise and vibration. In this paper, Korteweg-Helmholtzs energy method and equivalent magnetic charge method are employed for comparison of their resulting distributions of force density. The force density from the Korteweg-Helmholtzs method is expresses with two Maxwell stresses on the inside and the outside fo magnetic material respectively. The other is calculated using the magnetic Coulombs law. In the numerical model of an electromagnet, their numerical results are compared. The distributions by the two methods are almost the same. And their total forces are also shown to be the same to the one calculated from the conventional Maxwell stress tensor. But the magnetic charge method is easier and more efficient in numerical calculation.

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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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Nonlinear Vibration Analysis of Cantilever Beam Subject to Electromagnetic Force (전자력을 받는 외팔보의 비선형진동)

  • 최연선;서경석;우영주
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.283-288
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    • 2001
  • The nonlinear vibration of a cantilever beam due to electromagnetic force is studied. The dynamic responses of the beam show various phenomena with the variation of the system parameters, such as jump phenomenon, multiple solutions and the change of the natural frequency. The nonlinear stiffness due to electromagnetic forces which depends on air gap size is measured experimentally. This system was modeled by a single degree of freedom nonlinear dynamic system and solved numerically for the system parameters. The numerical results show good agreements with the experimental observations, which demonstrates the nonlinearity of magnetic force.

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The Analysis of Liquid Metal Flow Characteristics in the Annular Passage of an Electromagnetic Pump

  • Kim, Chang-Eob;Jeon, Mun-Ho;Kwon, Jeong-Tae;Lim, Hyo-Jae;Lee, Suk-Won
    • Journal of Electrical Engineering and Technology
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    • v.5 no.2
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    • pp.270-275
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    • 2010
  • An electromagnetic pump using a tubular induction motor (TLIM) has been proposed to pump liquid metal fluids. TLIM has been designed for liquid metal flow systems with a motor with a thrust force of 40~77[N]. The flow characteristics have been investigated by solving the Navier-Stokes equation, where the Lorentz force was included simply by considering it as a constant in the Navier-Stokes equation. A wood metal was chosen to simulate the liquid metal. The effect of Lorentz force on the flow rate was investigated. An experiment was conducted and its results were compared with those of the simulation. The simulation result showed an overestimation of about 17% compared with the experimental one.