• Title/Summary/Keyword: Magnetization characteristic

Search Result 76, Processing Time 0.035 seconds

Characteristic Analysis of a Flux-Lock Type SFCL Considering Magnetization Characteristic of Iron Core (철심의 자화특성을 고려한 자속구속형 초전도 사고전류제한기의 특성 분석)

  • Lim, Sung-Hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.20 no.11
    • /
    • pp.995-999
    • /
    • 2007
  • We investigated the characteristics of a flux-lock type superconducting fault current limiter(SFCL) considering magnetization characteristic of iron core. The flux-lock type SFCL, like other types of SFCLs using the iron core, undergoes the saturation of the iron core during the initial fault time. Therefore, if the design to prevent the saturation of the iron core is considered, the effective fault current limiting operation can be achieved. Through the analysis for its equivalent circuit including the magnetization characteristic of the iron core, the limiting impedance of the flux-lock type SFCL was drawn. The magnetization currents and the limited currents of SFCL, which were dependent on the winding direction and the turns' ratio between two coils, were investigated from the short circuit experiment. It was confirmed that their experimental results agreed with the analysis ones.

Characteristic of Magnetic Shielding Type High-Tc Superconducting Fault Current Limiter Using Magnetization Curve of Iron Core (철심의 자화곡선을 이용한 자기차폐형 고온초전도 전류제한기 특성)

  • Lee, Jae;Lim, Sung-Hun;Song, Jae-Joo;Kim, Jun-Hyuok;Han, Byoung-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.07a
    • /
    • pp.511-514
    • /
    • 2002
  • In this paper, we compared the characteristic of fault current liminting in the magnetic shielding type High-Tc superconducting fault current limiter(FCL) using both Piecewise linear magnetization curve and real magnetization one of iron core. From this paper, the characteristics of fault current limiting in both cases showed many differences. The latter has higher fault current than the former, because the saturation of iron core was reflected and more accumulated during fault. It is expected that the more exact characteristic of magnetic shielding type High-Tc superconducting FCL was obtained in the case of design and modeling.

  • PDF

Dynamic Analysis of Line Start Permanent Magnet Motor Considering Magnetization (착자를 고려한 Line Start Permanent Magnet Mortor의 동특성 해석)

  • Lee, C.G.;Kwon, B.I.
    • Proceedings of the KIEE Conference
    • /
    • 2002.04a
    • /
    • pp.15-17
    • /
    • 2002
  • In this paper, we analyse the dynamic characteristic of 3-phase line start permanent magnet motor considering magnetization. Magnetization vector of NdFeB is obtained from the 2-D FEM magnetization analysis. And comparing the proposed analysis with conventional analysis method, we know that it is necessary to consider magnetization in dynamic analysis.

  • PDF

Characteristic Analysis of Permanent-Magnet Linear Eddy-Current Brake System According to Magnetization Pattern (자화패턴에 따른 영구자석 직선형 와전류 제동장치의 특성 해석)

  • 이성호;조한욱;장석명
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.52 no.9
    • /
    • pp.427-433
    • /
    • 2003
  • Permanent magnet movers with three different magnetization patterns were applied to a linear eddy current braking system. By using a two-dimensional analytical technique, this paper deals with the comparison of the design guidelines, magnetic field, required magnet volume, and force capability for three types of linear brakes. The analytical results are also verified by finite element analyses.

Irreversible Magnetization of MgB2 Superconductor

  • Kim, Mun-Seog;Kim, Kyu-Tae;Kim, Wan-Seop;Park, Po-Gyu;Lee, Kyu-Won;Lee, Sung-Ik
    • Journal of Magnetics
    • /
    • v.10 no.4
    • /
    • pp.157-162
    • /
    • 2005
  • We report the magnetic-field dependence of the irreversible magnetization of binary superconductor $MgB_2$. For the temperature region of $T\;<\;0.9T_c$, the contribution of the bulk pinning to the magnetization overwhelms that of the surface pinning. This was evident from the fact that the magnetization curves, M(H), were well described by the critical-state model without considering the reversible magnetization and the surface pinning effect. It was also found that the M(H) curves at various temperatures scaled when the field and the magnetization were normalized by the characteristic caling factors H$\ast$(T) and M$\ast$(T), respectively. This feature suggests that the pinning mechanism determining the hysteresis in M(H) is unique below $T\;=\;T_c$.

A Study on Characteristic of Spindle Motor by Unsymmetric Magnetization Distribution in Permanent Magnet (비대칭 착자에 따른 스핀들 모터 특성에 관한 연구)

  • Park, Jae-Young;Bae, Jae-Nam;Kim, Ki-Chan;Lee, Ju
    • Proceedings of the KIEE Conference
    • /
    • 2008.10c
    • /
    • pp.38-40
    • /
    • 2008
  • Distribution of Permanent magnet used in the spindle motor on the ODD is arranged by magnetizer. In general, permanent magnet is putted between yoke and back yoke of magnetizer so that symmetric magnetization distribution. But the magnet has unsymmetric magnetization distribution because of eccentricity of the yoke in mass production. So, in this paper we discuss the effect of asymmetric magnetization distribution on back EMF and cogging torque of the spindle motor.

  • PDF

Thermomagnetic Characteristics of the Hard Magnetic Materials with a Fine Microstructure due to a HDDR Process

  • Kwon, H.W.;Kim, Yoon-B.;Jeung, W.Y.
    • Journal of Magnetics
    • /
    • v.4 no.1
    • /
    • pp.26-32
    • /
    • 1999
  • The HDDR process can be used as an effective means of processing of the coercive Nd-Fe-B-type or the Sm2Fe17Nx materials. The HDDR (hydrogenation, disproportionation, desorption, recombination) processed materials are feartured with a very fine microstructure. The thermomagnetic characteristics of the Nd-Fe-B-type or the Sm2Fe17Nx materials with fine microstructure due to the HDDR process were investigated. It has been found that the fine-microstructured hard magnetic materials showed an unusual TMA (Thermomagnetic analysis) tracting featured with a low and constant magnetization at lower temperature range and a peak just below their Curie temperatures when a low external field is applied. This thermomagnetic characteristic was immediate particularly in the TMA with a low applied field. This thermomagnetic characteristic was interpreted in terms of the competition between two counteracting effects; the decrease in magnetication due to the thermal agitation at an elevated temperature and the increase in magnetization resulting from the rotation of magnetization of the fine grains comparable to a critical single domain size due to the decreased magnetocrystalline anisotropy at an elevated temperature.

  • PDF

Manufacturing and characteristic if the magnet for generating a homogeneous magnetic field (균둥 자계 발생용 마그테트의 제작 및 특성)

  • 최세용;나완수;이세희;박일한
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
    • /
    • 1999.02a
    • /
    • pp.73-76
    • /
    • 1999
  • Superconductors are dissipative when exposed to time-varying magnetic fields. To analyze the AC characteristics of the superconductor, one usually needs to know magnetization curves of it. A good magnetization curves can be obtained only in a homogeneous magnetic field. In this paper, we report the fabrication and test results of a homogeneous magnet, which aims to give background magnetic fields for the superconductor.

  • PDF

Characteristic Analysis of the Linear Switched Reluctance Motor with Interior Permanent Magnet according to Magnetization of Permanent Magnet (영구자석 삽입형 직선형 스위치드 릴럭턴스 전동기의 전자기 특성 해석)

  • Jang, Seok-Myeong;Kim, Jin-Soon;Park, Ji-Hoon;Lee, Un-Ho;Goo, Cheol-Soo
    • Proceedings of the KIEE Conference
    • /
    • 2009.07a
    • /
    • pp.806_807
    • /
    • 2009
  • This paper deals with characteristic analysis on the Linear Switched Reluctance Motor with Interior Permanent Magnet (LSRM-IPM) according to the magnetization of permanent magnet. The governing equations and force equations are derived using analytical method for the suggested models. This paper compares the force characteristics in terms of three cases considering the position and size of permanent magnet.

  • PDF

Nonequilibrium Domain Configurations Undergoing Large Angle Rotations in Mesoscopic Magnetic Thin Film Elements (retracted)

  • Choi, B.C.;Hong, Y.K.;Rudge J.;Donohoe G.;Xiao Q.F.
    • Journal of Magnetics
    • /
    • v.11 no.2
    • /
    • pp.61-65
    • /
    • 2006
  • The physical origin of complex dynamic domain configuration in nonequilibrium magnetic systems with mesoscopic length scales has been studied. An increasing complexity in the spatial feature of the evolution is found to accompany the increasing reversal speed, when a ferromagnetic element is driven by progressively faster switching fields applied antiparallel to the initial magnetization direction. As reversal rates approach the characteristic precession frequencies of spin fluctuations, the thermal energy can boost the magnetization into local configurations which are completely different from those experienced during quasistatic reversal. The sensitive dependence of the spatial pattern on switching speed can be understood in terms of a dynamic exchange interaction of thermally excited spins; the coherent modulation of the spins is strongly dependent on the rise time of switching pulses.