• Title/Summary/Keyword: electromagnetic method

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Analysis of Electromagnetic Shielding Performance for a BiMODAL Tram using an Electromagnetic Concentration Index (전자파의 집중도를 이용한 바이모달 트램의 전자파 차폐 성능 분석)

  • Choi, Nak-Sun;Jeung, Gi-Woo;Kim, Nam-Kyung;Song, Myung-Kon;Lee, Kang-Won;Mok, Jai-Kyun;Kim, Dong-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.7
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    • pp.1378-1384
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    • 2011
  • In this paper, the electromagnetic shielding performance of a BiMODAL Tram is investigated by means of an electromagnetic analysis tool, called HFSS. For the purposed of doing this, first, three-dimensional finite element modeling for the tram including electronic devices and engine room is carried out. Then, for quantitatively assessing the electromagnetic shielding performance of the tram's body, concentration indexes for electric field magnitude and time-average stored electric energy are introduced. From numerical results, it is inferred that the tram's body can protect the electronic devices and engine room against external electromagnetic waves from 30 MHz to 100 MHz.

A Finite-element Method Analysis of Electromagnetic Noise Absorption in a Coplanar Transmission Line Integrated with a Magnetic Film

  • Sohn, Jae-Cheon;Han, Suk-Hee;Lim, Sang-Ho
    • Journal of Magnetics
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    • v.11 no.2
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    • pp.90-94
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    • 2006
  • A finite-element method is used to analyze loss generation and electromagnetic noise absorption characteristics of a coplanar waveguide transmission line integrated with a magnetic thin film. Parameters used in the analysis are the electrical resistivity of the magnetic layer and the thickness of both magnetic and insulating layers. The results indicate that L-C resonance is the main loss mechanism of the electromagnetic noise absorption.

Numerical Analysis of Electromagnetic Fields in TEM Cells (TEM CELL에서의 전자장 수치해석)

  • 이애경;이상회;김정기
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.1
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    • pp.37-45
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    • 1991
  • The electromagnetic field distribution within rectangular coaxial transmission lines (RCTL:TEM cells) is calculated using a numerical method. Boundary integral equations(BIE) considering equivalence theorem and extended boundary condition(EBC) in tapered region are used, thereby restricting the operational frequencies (0~130 MHz) below the cell cutoff frequency(130 MHz). The EM fields within NIST TEM cell ($1\times0.6\times2m$) are calculated by this method. The results of the numerical calcuation have a good agreement in the cross-sectional EM field distribution of TEM cell with 2-dimensional analysis results. Based on this method, the first cutoff freque- ncy in high order modes in the cell and the electric field polarization are considered.

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A Comparative Study on Measuring Methods of Absorption Characteristics for Electromagnetic Wave Absorber Using Time Domain Method (Time Domain법에 의한 전파흡수체의 흡수능 측정법의 비교연구)

  • 김동일;김상태;박지용;정세모
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.2
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    • pp.11-18
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    • 1995
  • The goal of this research is to get a measuring system for absorption characteristics of electromagnetic wave absorbers in fernite type which are flat, grid-type and special type, etc. It is, however, very difficult to measure the absorption characteristics in as low frequency as 30 MHz. To solve the problem, therefore, we propose a standing wave method and a measurement method in time domain using paralledl striplines, construct the measuring system, and measure the charac- teristics of ferrite microwave absorbers in grid type using the proposed measuring system.

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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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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.

Design of 3-Axis Moving Magnet Type Electromagnetic Actuator using Integrated Design Method (통합설계방법을 적용한 가동자석형 3축 액추에이터의 설계)

  • Kim, Sang-Young;Park, No-Cheol;Park, Young-Pil;Park, Kyoung-Su
    • Transactions of the Society of Information Storage Systems
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    • v.7 no.2
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    • pp.80-84
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    • 2011
  • In this paper, we propose the integrated design method that enables multi-physics modeling and coupled-field analysis by connecting an electromagnetic field and a structural field. We design the 3-axis moving magnet type actuator that has the high structural stiffness and the effective electromagnetic circuit generating large electromagnetic force. Through design of experiments (DOE) and optimization, the designed actuator is optimized and satisfies high dynamic characteristics over the desired specifications.

FDTD Analysis of the Absorption Characteristics for Grid Ferrite Electromagnetic Wave Absorber (FDTD를 이용한 격자형 페라이트 전파흡수체 특성 해석)

  • 이재용;정연춘;명노훈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.4
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    • pp.483-490
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    • 1998
  • The reflectivity of a grid ferrite electromagnetic wave absorber is analyzed using finite difference time domain (FDTD) method, which is usually used in anechoic chambers for EMI / EMS test. The frequency dispersive characteristics of ferrite medium and its boundary condition are modeled using magnetic flux in addition to E- and H-fields. By applying Floquets theorem, FDTD analysis of the grid ferrite absorber with periodic infinite array is simplified as a unit cell problem. The method of homogenization which is mainly utilized in the calculation of absorber reflectivity as a low frequency technique takes only into account volume fraction of the unit cell of the absorber except for the structure of medium geometry. However, the presented method in this paper can analyze the geometry effect of the unit cell with its medium characteristics up to high frequency region.

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Prediction of Antenna Propagation Characteristic in Space Environment Using Ray Tracing Method (광선 추적법을 이용한 우주 환경에서의 안테나 전파 특성 예측)

  • Kim, ChangSeong;Park, Yong Bae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.11
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    • pp.1023-1026
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    • 2016
  • We calculate the propagation characteristic of antennas considering refractive indices of space environments. The effective indices of troposphere, stratosphere, and inonshpere are computed and the ray tracing method, geometrical optics, and Huygens' principle are used to estimate refracted and attenuated electromagnetic wave of space environment.

Electromagnetic force analysis of electromagnetic pump (솔레노이드형 전자펌프의 전자력 해석)

  • Joung, Yung-Hwa;Ahn, Chang-Hoi;Kim, Dong-Hee;Kim, Han
    • Proceedings of the KIEE Conference
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    • 1995.07a
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    • pp.80-82
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    • 1995
  • The electromagnetic force of magnetic plunger for electromagnetic pump system are calculated by finite element method which consider the eddy current, the plunger motion. The mechanical motion equation are solved Rune-Kutta method, and coupled with the finite element method. With the external circuit equation dynamic simulation of the pump system are achieved. Electrostatic flux is verified by comparing with other commercial analysis software. Similar analysis of other type solenoidal actuators can be done by this procedure.

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