• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.256.1-256.1
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• 2008

• 전기학회논문지
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• 제60권9호
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• pp.1684-1692
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• 2011

Recently, several vector hysteresis models such as vector Preisach, vector Jiles-Atherton and dynamic E&S model have been proposed to describe vector magnetic properties of electrical steel sheets. However, it is still difficult to find an adequate vector hysteresis model in finite element application for both the Non-oriented and Grain-oriented electrical steel sheets under alternating and rotating field conditions. In this paper, an improved E&S vector hysteresis model is suggested to describe the vector magnetic properties of both Non-oriented and Grain-oriented electrical steel sheets under various magnetic field conditions including alternating and rotating magnetic field conditions. The validity of the proposed model is tested through comparisons with the experimental results under various magnetic field conditions.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권5호
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• pp.250-257
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• 2006

It is well known that Grain-oriented electrical steel sheets have two dimensional magnetic properties according to the direction of exciting field such as non-linear phase difference between magnetic flux density and magnetic field intensity vectors, different iron loss and permeability even when an alternating magnetic field is applied. The measurement and application of the two dimensional magnetic properties of the Grain-oriented electrical steel sheets, therefore, are very important for the design and precise performance analysis of electric machines made of them. As the direction of exciting field changes, in this paper, the two dimensional magnetic properties of a Grain-oriented electrical steel sheet, i.e., non-linear B-H curves, phase difference between B and H, and iron loss characteristics, are measured using SST(Single Sheet Tester) which has two axes excitation. The measured results are presented in two ways: using $(B,\theta_B)$ method and using hysteresis loops along rolling and transverse directions, respectively.

• Journal of Magnetics
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• 제22권1호
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• pp.93-99
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• 2017

The effort attempts to investigate the influence of various non-oriented electrical steel sheets on the core loss of a switched reluctance motor (SRM). The core loss of the motor inherits a strong correlation with flux density and permeability of the material. The study involves the use of laminated 2.7 % high silicon steel suitable for the motor in view of its higher flux density and lower core loss. The accurate prediction of core loss leaves way to suggest measures for improving the performance of the SRM. The dynamic simulation measurements of a 1.5 kW, three-phase 12/8 SRM involve the finite element method (FEM) and use the data obtained experimentally from Epstein frame. The closeness of the simulated and hardware results obtained with laminations of M400-50A, DI MAX-M19 and DI MAX-M15 both for the stator and rotor, espouse a greater significance to the findings in terms of the core loss density and forge new dimensions for its use in the drive industry.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권12호
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• pp.617-622
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• 2006

It is necessary to measure precisely the magnetic characteristics of electrical steel sheets under rotating magnetic fields, to obtain an accurate numerical performance analysis of electric machines made of electrical steel sheets. In this paper, the two dimensional magnetic characteristics of an electrical steel sheet are measured and explained under rotating magnetic fields using a two-axes-excitation type single sheet tester (SST). Through experiments, the magnetic properties, under rotating magnetic fields, of a non-oriented and grain oriented electrical steel sheet were measured respectively. In addition, the iron losses due to not only the alternating magnetic fields, but also rotating magnetic fields were measured. These experimentally measured results can evidently be applied to the analysis of iron losses in electrical machines.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.890-891
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• 2011

This paper presents efficiency improvement of a universal motor used in a vacuum cleaner. The transient computation is carried out by employing finite element analysis with nonlinear material curves. Working point of magnetic field is investigated and operating frequencies are analyzed using harmonics analysis. New non-oriented electrical steel is developed for the motor regarding permeability and iron loss at the frequencies. Accordingly, new electrical steel is applied to the motor, which leads to improve efficiency of the motor.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권10호
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• pp.461-469
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• 2005

In this paper, a double-excitation type single sheet tester is developed to measure the magnetic characteristics of the electrical steel sheets. The developed system has the uniform magnetic field area of 20$\times$20mm$^{2}$, and can be applied to the measurement of the magnetic characteristics of the Non-oriented and Grain oriented electrical steel sheets. In the developed system, the magnetic flux density and magnetic field intensity are measured by using B-coil and H-coil, respectively. The B-coil has 1 turn search coil for each direction, and H-coil has 640 and 640 turns for rolling direction and transverse direction on the Im thickness Glass-Epoxy basement, respectively. Through experiments, it Is shown that the system can measure the magnetic characteristics up to 1.87 of magnetic flux density in the rolling direction in case of the Grain oriented electrical steel sheet. The measured results are compared with those measured in Okayama university, .Japan.

• 한국철도학회논문집
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• 제15권4호
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• pp.376-380
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• 2012

IPMSM의 구동 중에 발생되는 철손은 코어 재료 특성에 의해 크게 좌우되며, 일반적으로 회전형 전동기에서는 모든 자속의 흐름 방향으로 자기적 특성이 동일한 무방향성 전기강판이 코어 재료로 사용된다. 무방향성 전기강판과 비교하여 방향성 전기강판은 자속의 흐름 방향으로의 자기적 특성이 우수한 장점을 가지고 있다. 따라서 본 연구에서는 IPMSM의 철손을 저감시키기 위하여 코어 재료로써 무방향성 전기강판과 방향성 전기강판을 동시에 사용하는 구조를 제안하였다. IPMSM의 고정자에 자속 흐름의 방향으로 가공된 방향성 전기강판을 이용한 분할 티스 구조를 적용함으로써 기존의 110kW급 IPMSM과 비교하여 거의 40% 정도의 철손 저감 효과를 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.625-626
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• 2008

The magnetic domain-refining techniques such as ball scratching, laser irradiation and plasma have been developed to reduce the domain wall spacing and thus iron losses in Fe-3%Si grain-oriented silicon steels. In view point of magnetic properties, it was supposed that the locally residual stresses change the magnetoelastic energy of the material and thus the spacing between $180^{\circ}$ domain walls decreases in order to reduce the magnetostatic energy. The effect of laser irradiation on iron loss and magnetostriction reduction for Fe-3%Si grain-oriented steel were investigated. Since the local tensile stresses were induced at the surface of Fe-3%Si steel by the laser irradiation, the minimum iron loss caused by reducing eddy current loss was obtained in spiete of the decrease of permeability by hindering eddy current loss was obtained in spite of the decrease of permeability by hindering the domain wall movement around the induced stress field. Furthermore, the laser treated 3%Si steel has lower magnetostriction as compared to non laser-treated steel and is less sensitive to applying pre-stresses due to the volume reduction of $90^{\circ}$ domain in materials.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2002년도 춘계학술발표회 초록집
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• pp.15-15
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• 2002