• 제목/요약/키워드: electromagnetic analysis

검색결과 2,907건 처리시간 0.035초

전자계-기계계 결합해석에 의한 건식변압기의 단락강도 예측 (Short Circuit Electromagnetic Force Prediction by Coupled Electromagnetic-Mechanical Field Analysis of Dry-Type Transformer)

  • 안현모;한성진
    • 전기학회논문지
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    • 제60권2호
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    • pp.301-308
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    • 2011
  • This paper deals with the coupled electromagnetic-mechanical field analysis for short-circuit electromagnetic force of the dry-type transformer. The short-circuit currents are calculated using external circuit in accordance with short-circuit test equipment. According to short-circuit current, the generated magnetic leakage flux density in dry-type transformer model is calculated by finite element method. The radially-directed electromagnetic forces in windings are calculated using electromagnetic field analysis and then axially-directed electromagnetic forces in windings are calculated using electromagnetic-mechanical field analysis. The calculated axially-directed electromagnetic forces in high voltage winding are compared to those of measured ones and showed good agreement with experimental results.

Electromagnetic Forming Process Analysis Based on Coupled Simulations of Electromagnetic Analysis and Structural Analysis

  • Lee, Man Gi;Lee, Seung Hwan;Kim, Sunwoo;Kim, Jin Ho
    • Journal of Magnetics
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    • 제21권2호
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    • pp.215-221
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    • 2016
  • We conducted a phased electromagnetic forming process analysis (EFPA) over time through a coupling of electromagnetic analysis and structural analysis. The analysis is conducted through a direct linkage between electromagnetic analysis and structural analysis. The analysis process is repeated until the electric current is completely discharged by a formed coil. We calculate the forming force that affects the workpiece using MAXWELL, a commercial electromagnetic finite element analysis program. Then, we simulate plastic behavior by using the calculated forming force data as the forming force input to ANSYS, a commercial structure finite element analysis program. We calculate the forming force data by using the model shape in MAXWELL, a commercial electromagnetic finite element analysis program. We repeat the process until the current is fully discharged by the formed coil. Our results can be used to reduce the error in data transformation with a reduced number of data transformations, because the proposed approach directly links the electromagnetic analysis and the structural analysis after removing the step of the numerical analysis of a graph describing the forming force, unlike the existing electromagnetic forming process. Second, it is possible to simulate a more realistic forming force by keeping a certain distance between nodes using the re-mesh function during the repeated analysis until the current is completely discharged by the formed coil, based on the MAXWELL results. We compare and review the results of the EFPA using the peak value of the forming force that acts on the workpiece (which is the existing analysis method), and the proposed phased EFPA over time approach.

순차적 전자기-구조 연성해석을 통한 전자기성형 공정 해석 (Analysis of Electromagnetic Forming Using Sequential Electromagnetic-Mechanical Coupled Simulations)

  • 김정;노학곤;고세진;김태정
    • 소성∙가공
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    • 제21권7호
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    • pp.441-446
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    • 2012
  • A sequential coupled field analysis of electromagnetic free bulging was performed by using FEM. A 2D axi-symmetric electromagnetic model based on the magnetic vector potential is proposed for the calculation of magnetic field and Lorentz's forces. The Newmark integration method is used to calculate the transient dynamic plastic deformation of sheet during free bulging. In the finite element model, the effect of sheet deformation on the electromagnetic field analysis is taken into consideration. In order to confirm the sequential electromagnetic-mechanical coupling analysis, an experiment with an electromagnetic forming apparatus was conducted. The results showed that the final bulge height of the sheet predicted from the proposed method is in good agreement with experimentally measured height.

Design and Experiment of an Electromagnetic Vibration Exciter for the Rapping of an Electrostatic Precipitator

  • Kim, Je-Hoon;Kim, Jin-Ho;Jeong, Sang-Hyun;Han, Bang-Woo
    • Journal of Magnetics
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    • 제17권1호
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    • pp.61-67
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    • 2012
  • The miniaturization of an electrostatic precipitator has become a key element in successfully constructing an efficient electrostatic precipitator because of the limited space allowed for installation in a subway tunnel. Therefore, the miniaturization of the rapping system of the electrostatic precipitator has also become important. This research proposes a resonant-type electromagnetic vibration exciter as a vibrating rapper for an electrostatic precipitator. The compact vibrating rapper removes collected dust from the collecting plates without direct impact on those collecting plates. To characterize the dynamic performance of the electromagnetic vibration exciter, finite element analysis was performed using a commercial electromagnetic analysis program, MAXEWLL. Moreover, we analyzed the resonant frequency of an electrostatic precipitator, to which the electromagnetic vibration exciter was applied, by ANSYS. Also, to measure the acceleration generated by the electromagnetic vibration exciter, we manufactured a prototype of the ESP and electromagnetic vibration exciter and measured its acceleration at the resonant frequency.

500MW 급 대형 발전기 권선단부의 전자기력과 동특성 해석 (Analysis of Vibration and Electromagnetic Forces on a Generator End-winding for 500 MW Fossil Power Plant)

  • 김철홍;주영호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.826-831
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    • 2001
  • Electromagnetic forces generate vibrations in the end-winding of large generators. A finite element analysis using a commercial S/W is performed to calculate electromagnetic force of end-winding in two pole generator for 500 MW fossil power plant. Also, this paper presents analytical and experimental modal analysis results of generator end- winding. Using validated FE model, 3D electromagnetic model which computes the forces on the end-winding is coupled with a 3D mechanical model which calculates the dynamic displacement and stress under electromagnetic forces. These results will be used to evaluate reliability of end-winding and applied to update model.

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성능이 보완된 PWB 방법을 사용한 외부 전자기파에 의한 대형 건물 내부의 전자기파 영향 해석 (Analysis of Electromagnetic Effect Inside Large Buildings by External Electromagnetic Waves Using Performance-Enhanced PWB Method)

  • 이한희;이재욱
    • 한국전자파학회논문지
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    • 제30권1호
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    • pp.12-22
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    • 2019
  • 본 논문은 외부 전자기파에 의한 대형 건물 내부의 전자기파 해석을 보다 효율적으로 계산하기 위한 방법을 제시한다. 대형 건물에서의 전자기파 해석을 위해 위상학적 해석과 PWB 방법을 도입하였다. 기존 PWB 방법을 소개하고, PWB 방법의 성능을 보완하는 방법을 제시하고 적용하여 정확도를 높였다. 가상의 대형 구조물을 선정하고, 전자기파 입사환경을 설정하여 외부 전자기파에 의한 대형 건물 내부의 전자기파 해석을 진행하였다. 성능이 보안된 PWB 방법의 정확도를 검증하기 위해 상용 시뮬레이션 툴인 Wireless Insite를 사용하였다. 두 결과를 정확도, 시간, 메모리 관점에서 비교한 결과, 외부 전자기파에 의한 대형 구조물 내부의 전자기파 해석에 성능이 보완된 PWB 방법이 효율적인 방법임을 확인하였다.

Dynamic interaction analysis of actively controlled maglev vehicles and guideway girders considering nonlinear electromagnetic forces

  • Min, Dong-Ju;Lee, Jun-Seok;Kim, Moon-Young
    • Coupled systems mechanics
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    • 제1권1호
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    • pp.39-57
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    • 2012
  • This study intends to explore dynamic interaction behaviors between actively controlled maglev vehicle and guideway girders by considering the nonlinear forms of electromagnetic force and current exactly. For this, governing equations for the maglev vehicle with ten degrees of freedom are derived by considering the nonlinear equation of electromagnetic force, surface irregularity, and the deflection of the guideway girder. Next, equations of motion of the guideway girder, based on the mode superposition method, are obtained by applying the UTM-01 control algorithm for electromagnetic suspension to make the maglev vehicle system stable. Finally, the numerical studies under various conditions are carried out to investigate the dynamic characteristics of the maglev system based on consideration of the linear and nonlinear electromagnetic forces. From numerical simulation, it is observed that the dynamic responses between nonlinear and linear analysis make little difference in the stable region. But unstable responses in nonlinear analysis under poor conditions can sometimes be obtained because the nominal air-gap is too small to control the maglev vehicle stably. However, it is demonstrated that this unstable phenomenon can be removed by making the nominal air-gap related to electromagnetic force larger. Consequently it is judged that the nonlinear analysis method considering the nonlinear equations of electromagnetic force and current can provide more realistic solutions than the linear analysis.

EMI/EMC 환경에서 PCB와 Frame구조물의 전자기 방사특성 해석 (Numerical Analysis of Electromagnetic Radiation Characteristic of PCB and Frame Structure in EMI/EMC)

  • 최윤석;김영선;황보훈;박일한
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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    • pp.715-716
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    • 2006
  • Nowadays, research of EMI/EMC is very important in electromagnetic wave surroundings generated from many electric and electronic devices. Especially, analysis of electromagnetic radiation characteristic and field have to be performed first of all. At the present most of EMI/EMC problems are solved by the method of practice and inspiration. Hence in this paper, will provide the first step for solving EMI/EMC problems in design process. Model of analysis is structure composed of PCB and Frame. By the first step, theory of dipole antenna is adapted to analyze electromagnetic radiation characteristic and field. Because it is fundamental of analysis of electromagnetic radiation. And it will be expanded for structure of PCB and Frame. Finally, it provide the basic method of analysis of electromagnetic radiation characteristic and field by making similar dipole antenna to PCB and Frame structure.

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전자기력에 의한 발전기 고정자 코어의 진동 해석 (Vibration Analysis of a Generator-Stator Core Under Electromagnetic Excitation)

  • 김철홍;주영호;박종포
    • 소음진동
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    • 제9권4호
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    • pp.747-753
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    • 1999
  • This paper presents results of vibration analysis of a generator-stator core for 500 MW fossil power plant. A finite element analysis using a commercial S/W is performed to estimate alternating electromagnetic forces, mainly of 120 Hz in 60 Hz machines, acting on the core, and then to calculate forced response of the core. Results are compared with design requirements.

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Electromagnetic Interference Analysis of an Inhomogeneous Electromagnetic Bandgap Power Bus for High-Speed Circuits

  • Cho, Jonghyun;Kim, Myunghoi
    • Journal of information and communication convergence engineering
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    • 제15권4호
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    • pp.237-243
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    • 2017
  • This paper presents an analysis of the electromagnetic interference of a heterogeneous power bus where electromagnetic bandgap (EBG) cells are irregularly arranged. To mitigate electrical-noise coupling between high-speed circuits, the EBG structure is placed between parallel plate waveguide (PPW)-based power buses on which the noise source and victim circuits are mounted. We examine a noise suppression characteristic of the heterogeneous power bus in terms of scattering parameters. The characteristics of the dispersion and scattering parameters are compared in the sensitivity analysis of the EBG structure. Electric field distributions at significant frequencies are thoroughly examined using electromagnetic simulation based on a finite element method (FEM). The noise suppression characteristics of the heterogeneous power bus are demonstrated experimentally. The heterogeneous power bus achieves significant reduction of electrical-noise coupling compared to the homogeneous power buses that are adopted in conventional high-speed circuit design. In addition, the measurements show good agreement with the FEM simulation results.