• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.168-172
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• 2005

A novel cogging torque reduction algorithm is presented for 2-pole permanent magnet DC motor. While the shape of the permanent magnet is changed in the conventional method, the pole shape of the magnetizing yoke is optimized in the presented algorithm. In order to parameterize the shape of the yoke, and the distribution of the residual magnetization of the permanent magnet, the Bezier spline is used. The shape of the magnetizing yoke is optimized using the design sensitivity analysis incorporated with the finite element method and Bezier spline.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.334-336
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• 1998

This paper deals with the problem of the magnetizing yoke fixture. The experimental test has been performed using the yoke fixture made of bakelite as well as ferromagnetic. The magnetizing current is the most essential criterial factor for delivering the impulse energy to the magnetized material, i.e ferrite core. The yoke of nonferromagnetic has shown its better performance in experimental results as well as in the finite element analysis.

• 한국산업정보학회논문지
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• 제28권2호
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• pp.21-30
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• 2023

전기차 보급과 고성능화가 진행됨에 따라 높은 출력을 가지는 모터의 수요가 증가하고 고용량 IPMSM 생산을 위한 고용량 착자기의 중요성 또한 증가하고 있다. 착자에 중요한 착자 전류의 최댓값과 커패시터 방전시간은 착자요크의 회로정수에 의해 결정된다. 본 논문에서는 착자기 설계를 위한 착자요크의 회로정수 설계를 위하여 MATLAB SIMULINK를 활용한 착자 시스템의 해석을 진행하고 회로정수 설계를 위한 설계 절차를 제시한다. 그 결과 착자용량 5,000[V], 15,000[uF]에 따라 착자요크 파라미터는 0.015[ohm], 0.035[mH]로 도출하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.404-406
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• 2001

This paper is about designing the magnetizing system which is used for magnetizing the NdFeB magnet in a squirrel cage rotor. It propose the shape of the magnetizing yoke, the number of coil turn and the capacitor discharging circuit parameter. In case of magnetizing the NdFeB magnet assembled with a squirrel cage rotor, the eddy current which is produced during magnetizing becomes a disturbance in magnetizing NdFeB magnet. Hence in this paper, we try to design optimized magnetizing system with eddy current considered by FEM(Finite Element Method).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.118-121
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• 1991

The characteristics of magnetizing system considering the anisotropy and the nonlinearity are analyrized using PEM in This paper. The case of magnetizing the ferrite magnet with 12 poles is analyrized. The anisotropy characteristic is considered when ferrite magnet which is widely used as permanent magnet is magnetized. The Nonlinear characteristic of magnetizing yoke aid ferrite is considered because the current is in the saturation region. When the magnetizing current value is over the optimum value, the magnet is magnetized with 24 poles. This is not the case of our expectation. Thus, for the case of our expected magnetizing form, it is the conclusion that the optimum magnetizing current value is selected.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.27-29
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• 2001

In this paper, we study in magnetizing the NdFeB magnet which is inserted in a squirrel cage rotor. The inserted NdFeB magnet need much more magnetizing flux than that of ferrite magnet. Also the eddy current flowing in rotor bar disturbs the magnetizer in magnetizing the NdFeB magnet. The existing magnetizing yoke is designed by increasing the coil turn. But we recognize that only by increasing the coil turn it is impossible to make NdFeB magnet magnetized fully. Hence, in this paper we propose the method of increasing magnetizing flux by reducing the rotor bar area.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.99.2-99.2
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• 2008

• Journal of Magnetics
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• 제13권4호
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• pp.173-176
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• 2008

In this study, a new kind of instrument for measuring the magnetic shielding effectiveness (MSE) was developed using a double yoke; one a magnetizing yoke and the other a sensing yoke. Using the developed instrument, the MSE could be measured for a steel sheet specimen in the ELF range, where the magnetic permeability contributes to the MSE at low frequencies and eddy currents contributes to the MSE high frequencies with < 0.1 dB reproducibility. The developed measuring method can be applied to quality control in a steel sheet company producing EMI/EMC shielding materials.

• 한국자기학회지
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• 제2권2호
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• pp.145-149
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• 1992

영구자석의 착자상태는 영구자석이 사용된 기기의 특성에 큰 영향을 미친다. 따라서 영구 자석기기에서 원하는 특성을 얻기 위해서는 영구자석의 착자상태를 정밀하게 해석할 필요가 있다. 본 논문에서는 비선형과 이방성 특성이 고려된 유한요소법으로 착자기를 해석하였다. 착자전류가 변함에 따른 자화량의 분포와 그 자화량에 의하여 공극에 발생되는 저장의 값을 각도가 서로 다른 2가지 착 자요크에 대하여 구한 결과, 착자요크의 형상에 따라 과도한 착자전류는 자화량의 분포를 왜곡시키고, 이에따라 발생되는 공극에서의 자장의 값은 오히려 줄어듦을 알 수 있었다. 따라서 영구자석을 자화 시키기 위한 착자기를 설계할때 원하는 착자분포를 얻기위해서는, 착자요크의 각도에 따라 적절한 착 자전류의 값이 있음을 알 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.819-821
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• 2001

This paper describes a characteristics of MFL according to the position of Hall sensor Magnetic Flux Leakage(MFL) Method is used to detect surface defect in ferromagnetic plate. A plate has a surface defect and magnetizing equipment are producted to perform Non-Destructive Testing(NDT) using MFL. The SM 45C carbon steel plate is adopted to this experiment. there is a artifical defect with a twice of thickness and a half of depth of plate. Magnetizing equipment is composed of yoke made by layer-built of silicon sheet steel, NdFeB magnetic and iron brushes. Detecting defect is performed by MFL NDT using Hall sensor. It is shown that magnetic flux detected by Hall sensor is affected according to the position of Hall sensor through MFL experiment and numerical analysis.