• Title/Summary/Keyword: Maxwell

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Characteristics calculation on radio frequency power transfer in a planar inductively coupled plasma source (평면형 유도결합 플라즈마 장치에서의 RF 전력 전달 특성 계산)

  • 이정순;정태훈
    • Journal of the Korean Vacuum Society
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    • v.8 no.3B
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    • pp.368-375
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    • 1999
  • The Maxwell equation and the transformer equivalent-circuit model are applied to a radio frequency planar inductively coupled plasma. The spatial distribution of the vector potential, the magnetic field, and the electric field are obtained analytically. As a result, the plasma current, the mutual inductance between the coil and the plasma, and the self inductance of plasma are found to increase with increasing skin depth. The spatial distribution of absorbed power has maximum where the antenna coil exists, and has a similar profile to that of the induced electric field. The power transfer efficiency is found to increase with increasing gas pressure before a saturation around p+ 20mTorr, while it shows an increase with the plasma density before a slight decrease around a density of $5\times10^{11}/\textrm{cm}^3$.

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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.

Analysis of axial magnetic field of coil type vacuum interrupter electrodes by comparing effective area at mid-gap plane (유효면적비교를 통한 COIL TYPE 진공인터럽터 전극의 측자계 분석)

  • Kim, Byoung-Chul;Yoon, Jae-Hun;Hoe, Jun;Kang, Seong-Wha;Lim, Kee-Joe
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.147-148
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    • 2008
  • In this paper, we calculated the axial magnetic field at mid-gap plane between upper and lower electrode in vacuum interrupter by means of commercial finite element method Maxwell 3D and compared on the basis of "effective area" criterion. The models used in this paper are coil type(axial magnetic field) vacuum interrupter electrodes which have different numbers of coil segment. We used Dr. Schulmann's experimental equation which indicates minimum critical value of axial magnetic field to diffuse arc.

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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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    • 2007.10c
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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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Analysis of Radial Force and Vibration in Swithched Reluctance Drive (스위치드 릴럭턴스 전동기의 경방향 힘과 진동 해석)

  • Son, Dong-Hyeok;Li, Jian;Kim, Byong-Kuk;Moon, Ji-Woo;Cho, Yun-Hyun
    • Proceedings of the KIEE Conference
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    • 2007.10c
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    • pp.107-109
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    • 2007
  • This paper presents a dynamic force analysis of switched reluctance motor using 2D-transient finite element method. The main exciting of the vibration is the electiromagnetic force in the stator that is calculated Maxwell stress method. The advantage for elimation of vibration of 12/8 SRM was explained by comparing the radial force of 12/8 and 6/4 SRM in both time and frequency domain. In order to effective mitigate the vibration during turning off process, effects of different commutation method were investigated.

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A Study on Characteristics and Safety Criteria for Human Body in ELF Electric and Magnetic Fields (ELF 전자계 특성 및 인체 안전기준에 관한 연구)

  • 김두현;김상철
    • Journal of the Korean Society of Safety
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    • v.8 no.3
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    • pp.34-43
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    • 1993
  • This paper presents a study on the characteristics and safety criteria for human body in ELF (Extremely Low Frequency : 50-60Hz) electric and magnetic fields. Many researches for ELF electric and magnetic fields, which are developed in the past, are studied and analyzed In this paper. In order to estabilish the safety criteria for human body in the field, the field intensity, induced current and voltage are calculated by the electrostatic field approach which is far simpler than the electromagnetic field one based on Maxwell equation. The method is applied to the 345 KV transmission line system In operation and 765 KV system under consideration. According to the results, the maximum value of field intensity, 6.8627KV/m, is evaluated at the location which is 14m away from transmission line. As the safety criteria value by the abroad researches asserting that the human can detect the Induced current in 6KV/m and above, 5KV/m and 7KV/m are recommended at residence area and nonresidence area, respectively.

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Static behavior of thermally loaded multilayered Magneto-Electro-Elastic beam

  • Vinyas, M.;Kattimani, S.C.
    • Structural Engineering and Mechanics
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    • v.63 no.4
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    • pp.481-495
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    • 2017
  • The present article examines the static response of multilayered magneto-electro-elastic (MEE) beam in thermal environment through finite element (FE) methods. On the basis of the minimum total potential energy principle and the coupled constitutive equations of MEE material, the FE equilibrium equations of cantilever MEE beam is derived. Maxwell's equations are considered to establish the relation between electric field and electric potential; magnetic field and magnetic potential. A simple condensation approach is employed to solve the global FE equilibrium equations. Further, numerical evaluations are made to examine the influence of different in-plane and through-thickness temperature distributions on the multiphysics response of MEE beam. A parametric study is performed to evaluate the effect of stacking sequence and different temperature profiles on the direct and derived quantities of MEE beam. It is believed that the results presented in this article serve as a benchmark for accurate design and analysis of the MEE smart structures in thermal applications.

Rheological Properties of Mat-type Seedlings (Mat-묘(苗)의 리올러지 특성(特性))

  • Yi, C.K.;Huh, Y.K.
    • Journal of Biosystems Engineering
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    • v.14 no.1
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    • pp.8-15
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    • 1989
  • Agricultural materials do not react in a purely elastic manner, and their responses when subjected to stress and strain are appeared from a combination of elastic and viscous behavior. Various researchers have studied the mechanical and rheological properties of the many agricultural materials, but those properties are available mostly foreign varieties of agricultural products. Rheological properties of rice seedlings become important to formulate the principles governing their mechanical behavior. The objectives of this study were to experimentally determine the stress relaxation properties of rice seedlings such as three Japonica-type and one Indica ${\times}$ Japonica hybrid in the transplanting age. The results of this study are summarized as follows; 1. The stress relaxation behavior could be described by the generalized Maxwell model. 2. The phenomenon of stress relaxation happened abruptly just after loading and this phenomenon weakened with the loading time lapsed. 3. With increase of the initial stress, the stress relaxation intensity and residual stress increased, while the relaxation time was constant with increased, while the relaxation time was constant with increase of the level of initial stress. 4. With increase of loading rate, the stress relaxation intensity increased, while the relaxation time and residual stress decreased.

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Platform for Manipulating Polarization Modes Realized with Jones Vectors in MATHEMATICA

  • Choi, Yong-Dae;Kim, Bogyeong;Yun, Hee-Joong
    • Journal of Astronomy and Space Sciences
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    • v.32 no.2
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    • pp.151-159
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    • 2015
  • The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD) to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.

Development of Dark Current Sensor Core for Monitoring the Low-current of Automotive (자동차용 Dark Current 모니터링용 저전류 전류센서 마그네틱 Core 개발)

  • Choi, Jae-Young;Lee, Hee-Sung;Park, Jong-Min;Kim, Sung-Gaun
    • Proceedings of the KAIS Fall Conference
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    • 2012.05b
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    • pp.613-616
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    • 2012
  • 자동차 시장에서 늘어나는 전장부품으로 인하여 배터리 사용이 급증함에 따라 차량용 배터리가 암전류로 인하여 방전되는 사고가 급증하고 있다. 암전류로 인한 배터리 방전을 방지하기 위해 홀효과를 이용한 저전류 센서 마그네틱 Core를 개발한다. 본 논문은 Maxwell 전자기장 해석 툴을 이용하여 마그네틱 Core의 Airgap 위치와 간격 그리고 두께를 변수로 시뮬레이션을 하였다. 시뮬레이션 결과 저전류에서 기존의 홀효과를 이용한 전류 센서보다 높은 자속밀도가 발생하는 최적의 마그네틱 코어를 설계하였고 시제품을 제작하여 시뮬레이션 결과와 실제 실험결과를 비교분석 하였다.

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