• 제목/요약/키워드: magnetic field simulation

검색결과 486건 처리시간 0.037초

Characteristics of Time Varying Magnetic Fields in Thyristor Rectifiers of 19kA in Chlor-Alkali Industry

  • Shirmohammadi, Siamak;Suh, Yongsug
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2014년도 전력전자학술대회 논문집
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    • pp.383-384
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    • 2014
  • This paper investigates the experimental and simulated time-varying magnetic field generation in a chlor-alkali manufacturing process. 19kA thyristor-based rectifier is modeled and analyzed. The performance is compared and evaluated on the basis of exposure guidelines from ICNIRP. The mechanical structure of current carrying conductor is simplified as an infinite long busbar model and low frequency harmonic contents up to 65kHz are considered. Thyristor rectifier generates a significant amount of low frequency magnetic field harmonic contents both at ac and dc busbar of rectifier infringing the limit of ICNIRP. Along with simulation analysis the experimental measurement of the time-varying magnetic field in ac input busbar, rectifier block, dc load and busbar are presented. The experimental test results partly confirm the simulation results.

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MODELING OF A REPULSIVE TYPE MAGNETIC BEARING FOR FIVE AXIS CONTROL INCLUDING EDDY CURRENT EFFECT

  • Ohji, T.;Mukhopadhyay, S.C.;Iwahara, M.;Yamada, S.
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.625-629
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    • 1998
  • So far a single-axis controlled repulsive type magnetic bearing system have been designed and fabricated in our laboratory employing the repulsive forces operating between the stator and rotor permanent magnet for levitation. The radial axis is uncontrolled passive one. The higher speed of operation is limited due to the vibration along the uncontrolled axis and the increase of control current due to eddy current interference. This paper will discuss a detailed modeling of the repulsive type magnetic bearing system for five axis control including the eddy current effect and the method of reduction of eddy current effect. Simulation results using Matlab will be presented.

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ORIGINS OF THE FLOW AND MAGNETIC STRUCTURE INVOLVED IN THE FORMATION AND ERUPTION OF A SOLAR PROMINENCE

  • Magara, Tetsuya
    • 천문학회지
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    • 제54권5호
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    • pp.157-170
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    • 2021
  • We investigate flow and magnetic structure of a solar prominence with a focus on how the magnetic field originally determined by subsurface dynamics gives rise to the structure. We perform a magnetohydrodynamic simulation that reproduces the self-consistent evolution of a flow and the magnetic field passing freely through the solar surface. By analyzing Lagrangian displacements of magnetized plasma elements, we demonstrate the flow structure that is naturally incorporated to the magnetic structure of the prominence formed via dynamic interaction between the flow and the magnetic field. Our results explain a diverging flow on a U-loop, a counterclockwise downdraft along a rotating field line, acceleration and deceleration of a downflow along an S-loop, and partial emergence of a W-loop, which may play key roles in determining structural properties of the prominence.

영구자석조합형 축방향 자기베어링 시뮬레이션 및 실험 (Permanent Magnet Combined Thrust Magnetic Bearing Simulation and Experiment)

  • 박병철;정세용;한상철;이정필;한영희;박병준
    • Tribology and Lubricants
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    • 제27권3호
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    • pp.167-173
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    • 2011
  • In this paper, an actuator model of the thrust magnetic bearing for the flywheel energy storage is derived using magnetic circuit theory. And we compared this result with finite element magnetic field analysis result. Based on the actuator model, we made a simulation model of the thrust magnetic bearing system. We showed the closed loop transfer function and sensitivity function of the thrust magnetic bearing system using both the simulation model and the experiment. The experimental result at rotation velocity 18,000rpm of thrust magnetic bearing system is included.

Estimation of Output Voltage and Magnetic Flux Density for a Wireless Charging System with Different Magnetic Core Properties

  • Park, Ji Hea;Kim, Sang Woo
    • Journal of Magnetics
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    • 제18권2호
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    • pp.105-110
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    • 2013
  • The design model and key parameters of the material design for the control of induced magnetic flux at the near-field and efficient power transfer in a modified wireless power transfer (WPT) system with a large air gap of wireless electric vehicles were investigated through analytical simulations for magnetic vector and time-domain transient analysis. Higher saturation magnetic core with low core loss induced a stronger vertical magnetic field by the W-type primary coil in the WPT system with a gap of 20 cm at 20 kHz, which is shown from the vector potentials of the magnetic induction. The transient analysis shows that the higher magnetic fluxes through the pick-up cores lead to a linear increment of the alternating voltage with a sinusoidal waveform in the non-contact energy transfer system.

축자계형 진공인터럽터의 전자계 현상 해석 (Analysis of the Electromagnetic Phenomena in Vacuum Interrupter with Axial Magnetic Field Type)

  • 하성철;서상현
    • 한국전기전자재료학회논문지
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    • 제16권10호
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    • pp.952-957
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    • 2003
  • The purpose of this paper is analyses about in 12kV/50kA vacuum interrupter with an axial magnetic field type electrode system through the studies of electromagnetic phenomena. Vacuum interrupter is important in electric safety part. In this paper, we performed analysis of electric field, magnetic field, current density in AMF electrode using the Maxwell 3D simulation. The current distribution and magnetic field in simple models are analyzed to verify its efficiency and accuracy. In addition the validity of FEM is confirmed by performing the analyses of distribution in current density and magnetic flux density.

Effects of Transverse Magnetic Field on Laser-produced Carbon Plasma Plume in Nitrogen Atmosphere

  • Nam, Sang-Hwan;Ko, Min-Jung;Lee, Mi-Ae;Park, Hye-Sun;Song, Jae-Kyu;Park, Seung-Min
    • Bulletin of the Korean Chemical Society
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    • 제28권5호
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    • pp.767-771
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    • 2007
  • By adopting a time-resolved optical emission spectrometry, we have investigated the effects of transverse magnetic field on C2 and CN molecules produced by laser ablation of a graphite target in nitrogen atmosphere. We found that the spectroscopic temperatures of both species, obtained via simulation of the optical emission spectra, as well as their emission intensities from the electronically excited states increased significantly in the presence of a magnetic field. The cyclotron radii and frequencies for electrons and ions were estimated to explain the increase in the number of collisions in the laser-produced carbon plasma plume under a magnetic field.

Development of magnetic field measurement system for AMS cyclotron

  • Ho Namgoong;Hyojeong Choi;Mitra Ghergherehchi;Donghyup Ha;Mustafa Mumyapan;Jong-Seo Chai;Jongchul Lee;Hoseung Song
    • Nuclear Engineering and Technology
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    • 제55권8호
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    • pp.3114-3120
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    • 2023
  • A high-accuracy magnetic field measurement device based on a cyclotron is being developed for accelerator mass spectrometry (AMS). In this study, a magnetic field measurement device consisting of a Hall probe sensor, piezo-motor, and step motor was developed to measure the magnetic field of the AMS cyclotron magnet. The Hall probe sensor was calibrated to achieve positional accuracy by using polar coordinates. The measurement results between the ratchet gear and piezo-motor, which are the instruments used for driving the measurement device, were analyzed. The measurement result of the device with a piezo-motor exhibits a difference of 5 Gauss (0.04%) as compared with the simulation result.

Magnetic Field Gradient Optimization for Electronic Anti-Fouling Effect in Heat Exchanger

  • Han, Yong;Wang, Shu-Tao
    • Journal of Electrical Engineering and Technology
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    • 제9권6호
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    • pp.1921-1927
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    • 2014
  • A new method for optimizing the magnetic field gradient in the exciting coil of electronic anti-fouling (EAF) system is presented based on changing exciting coil size. In the proposed method, two optimization expressions are deduced based on biot-savart law. The optimization expressions, which can describe the distribution of the magnetic field gradient in the coil, are the function of coil radius and coil length. These optimization expressions can be used to obtain an accurate coil size if the magnetic field gradient on a certain point on the coil's axis of symmetry is needed to be the maximum value. Comparing with the experimental results and the computation results using Finite Element Method simulation to the magnetic field gradient on the coil's axis of symmetry, the computation results obtained by the optimization expression in this article can fit the experimental results and the Finite Element Method results very well. This new method can optimize the EAF system's anti-fouling performance based on improving the magnetic field gradient distribution in the exciting coil.

A simulation study on the variation of virtual NMR signals by winding, bobbin, spacer error of HTS magnet

  • Kim, Junseong;Lee, Woo Seung;Kim, Jinsub;Song, Seunghyun;Nam, Seokho;Jeon, Haeryong;Baek, Geonwoo;Ko, Tae Kuk
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권3호
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    • pp.21-24
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    • 2016
  • Recently, production technique and property of the High-Temperature Superconductor (HTS) tape have been improved. Thus, the study on applying an HTS magnet to the high magnetic field application is rapidly increased. A Nuclear Magnetic Resonance (NMR) spectrometer requires high magnitude and homogeneous of central magnetic field. However, the HTS magnet has fabrication errors because shape of HTS is tape and HTS magnet is manufactured by winding HTS tape to the bobbin. The fabrication errors are winding error, bobbin diameter error, spacer thickness error and so on. The winding error occurs when HTS tape is departed from the arranged position on the bobbin. The bobbin diameter and spacer thickness error occur since the diameter of bobbin and spacer are inaccurate. These errors lead magnitude and homogeneity of central magnetic field to be different from its ideal design. The purpose of this paper is to investigate the effect of winding error, bobbin diameter error and spacer thickness error on the central field and field homogeneity of HTS magnet using the virtual NMR signals in MATLAB simulation.