• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.208-211
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• 1995

This proper focuses on results of relative permeability(${\mu}$$\sub$r/), core loss(W) and magnetic induction [B] measurements on some of the most commonly used core materials(PN-18, 20, 30, 60, Pohang Iron '||'&'||' Steel Co., Ltd.) In case of Stress Relief Annealing(SRA). Results of magnetic induction[B] showed weak variations but core lass reduced strongly after SRA Core loss reduced from 3.071 ∼7.819(W/kg) and 11.377~3.988[W/kg] to 2.88~5.492[W/kg] and 1.213~2.134[W/kg] at 1.5[T] 50 Hz and 1.0 [T] 50Hz respectively after SRA. This SRA process leads to significant changes In magnetic properties and core loss of non-oriented silicon steel sheet.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1023-1024
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• 2011

This paper deals with an improved core loss calculation of Linear Oscillatory Motor from curve fitting method using modified Steinmetz equation considered anomalous loss. For an accurate calculation, magnetic field analyses in stator core considering, magnetic field analyses in stator core considering the time harmonics are performed. And using the nonlinear finite element analysis (FEM), we applied separated rotating and alternating magnetic filed to core loss calculation.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1191-1192
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• 2006

Eventhough Fe-6.5 wt.% Si alloy shows excellent magnetic properties, magnetic components made of the alloy are not totally because of its extremely low ductility. In order to overcome this demerit of alloy, 6.7 wt.% Si alloy powders were produced by gas atomization and then post-processed to form magnetic cores. By doing so, the total core loss could be minimized by reducing both hysteresis and eddy current loss. From our experiments, we were able to achive a core loss of $390mW/cm^3$ at 0.1 T and 50 kHz through proper processes and a permeability $\mu_{eff}$ of 68 at low frequency.

• Journal of Magnetics
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• 제8권2호
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• pp.93-97
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• 2003

For the induction motor and inverter type motor design, prediction and analysis of core loss including higher harmonics have been studied. In this work, we have generated two symmetrical ac minor loop in the fundamental hysteresis loop whose positions are zero induction region and saturation induction region, and we could pre-dict core loss including higher harmonics inductions. using the following modified superposition principle; $P_c(B_0,f_0,B_h,nf_0)=P_c(B_0,f_0)+(n-1)[K_1(B_0)P_{cL}(B_h,nf_0)+(1-k_1(B_0))P_{cH}(B_h,nf_0)].$Using this equation we could also analyze core losses including higher harmonic induction under different maximum magnetic induction, different amplitude of higher harmonic induction with different harmonic frequencies.

• Current Optics and Photonics
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• 제2권3호
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• pp.215-220
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• 2018

A novel porous-core hexagonal lattice photonic crystal fiber (PCF) is designed and analyzed for efficient terahertz (THz) wave propagation. The finite element method based Comsol v4.2 software is used for numerical analysis of the proposed fiber. A perfectly matched layer boundary condition is used to characterize the guiding properties. Rectangular air-holes are used inside the core to introduce asymmetry for attaining high birefringence. By intentionally rotating the rectangular air holes of porous core structure, an ultrahigh birefringence of 0.045 and low effective material loss of $0.086cm^{-1}$ can be obtained at the operating frequency of 0.85 THz. Moreover, single-mode properties, power fraction in air core and confinement loss of the proposed PCF are also analyzed. This is expected to be useful for wideband imaging and telecom applications.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1290-1295
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• 2014

In this paper, various configurations of octagonal wound transformer core topology, which has previously proved advantages on conventional wound cores, are studied. Each configuration has different joint types and different placement of joint zones on the core. Magnetic flux distributions and power losses of each configuration are analyzed and compared. Comparisons are based on both 2D&3D finite element simulations and experimental studies. The results show that, joint types and their placements on the core cause local flux accumulations and dramatically affect power loss of the core.

• Journal of Magnetics
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• 제20권2호
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• pp.138-147
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• 2015

The unique nano-scale inter-lamellar microstructure and unparalleled heat treatment process give our developed metal powder composite its outstanding magnetic property for power inductor & motor applications. Compared to the conventional polycrystalline Fe or amorphous Fe-Cr-Si-B alloys, our unique designed inter-lamellar microstructure strongly decreases the intra-particle eddy current loss at high frequencies by blocking the mutual eddy currents. The combination of optimum permeability, magnetic flux and extremely low core loss makes this powder composite suitable for high frequency applications well above 10 MHz. Moreover, it can be also possible to SMC core for high speed motor applications in order to increase the motor efficiency by decreasing the core loss.

• Journal of Magnetics
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• 제16권1호
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• pp.64-70
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• 2011

Surface-mounted permanent magnet (PM) machines were examined experimentally and theoretically, through power loss measurements and calculations. Windage, friction and copper losses were calculated using simple analytical equations and finite element (FE) analyses. Stator core losses were calculated by determining core loss coefficients through curve-fitting and magnetic behavior analysis through non-linear FE calculations. Rotor eddy current losses were calculated using FE analyses that considered the time harmonics of phase current according to load. Core, windage and friction open-circuit losses and copper loss were determined experimentally to test the validity of the analyses.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1993년도 추계연구발표회 논문개요집
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• pp.60-61
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• 1993

• 한국염색가공학회지
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• 제5권1호
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• pp.19-25
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• 1993

Plastic optical fibers(POFs) composed of poly(methylmethacrylate) (PMMA), polystyrene (PS), or polycarbonate(PC) as a core materials, and of fluorinated polymer or PMMA as a cladding were fabricated and their properties were investigated in this study. The attenuation loss of PMAA core POF was about 1,700 dB/Km at 660 nm, the loss of PS core POF was 1,800 dB/Km at 560 nm, and the loss of PC core POF was 2,200 dB/Km at 780 nm. These attenuation losses of POFs prepared ill this study were higher than those of commerically available POFs. Compared to PMMA and PS core POFs, PC core POF has excellent characteristics, including high thermal stability, high flexibility, and high impact strength.