• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.706-708
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• 2002

Vibration, giving rise to acoustical noise, is an important index of motor performance. The unbalance force due to rotor eccentricity caused by manufacturing imprecision or bearing defects is one possible source of excitation to vibration. With the advent of new high-energy magnetic material together with high precision motor applications, magnetic sources of vibration are becoming more serious. This paper introduces two types of high-speed slotless permanent magnet (PM) machine for electro-mechanical battery and investigates unbalance force due to static eccentricity with finite element method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.74-77
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• 2002

In this paper we present a novel temperature compensated Hall effect power IC for accurate operation of wide temperature and high current drive of the motor coil. In order to compensate the temperature dependence of Hall sensitivity with negative temperature coefficient(TC), the differential amplifier has the gain consisted of epi-layer resistor with positive TC. The material of Hall device and epi-resistor is epi-layer with the same mobility. The variation of Hall sensitivity is -38% at 150$^{\circ}C$ and 88% at - 40$^{\circ}C$. But the operating point(B$\sub$op/) and release point(B$\sub$RP/) of the Hall power IC are within ${\pm}$25%. The experimental results show very stable and accurate performance over wide temperature range of -40$^{\circ}C$ to 125$^{\circ}C$.

• 전기학회논문지
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• 제63권2호
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• pp.237-244
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• 2014

In this paper, we presented a study on the design of permanent magnet rotor for exterior rotor type brushless direct current(BLDC) motor. To reduce the cogging torque and torque ripple, the specific shape and magnetization pattern of permanent magnets in BLDC motors are suggested. Firstly, four permanent magnet models with different shapes and magnetization arrays are presented. The results from the finite element method(FEM), the most effective model for reducing cogging torque and torque ripple was presented. In addition, to confirm the steady state performance, the torque-speed characteristic analysis has been performed with variable speed and load. Finally, the best permanent magnet model for reducing cogging torque and torque ripple with appropriate torque-speed performance was selected through the comparison according to the device volume.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.197-199
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• 2006

This paper presents a analytical field solutions for the general class of Linear Brushless DC(LBLDC) motors with PM mover and 3-phase winding stator. In our magnetic field analysis, we have adopted an approach which can treat both magnetized material and winding from the each field analysis by magnetic vector potential considering 2-Dimensional slot modeling. Therefore, we give accurate analytical formulas and object function for design and parameters estimation by its magnetic field.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.297-299
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• 1997

The switched reluctance motor is an electric machine in which torque is produced by the tendency of its movable part to move to a position where the inductance of the excited winding is maxmized. It is as well as PM brushless do systems. It's many advantages-a wide speed range, and inherently simplicity and ruggedness, low manufacturing cost, make it a vigorous challenger to these drives. It is a fascinating machine with all kinds of interesting application possibilities. In this paper, the design and evaluate the performance is treated.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.945-950
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• 2013

This paper deals with the ellipse permanent magnet machines for the minimization of torque ripple based on electromagnetic field theory. On the basis of a magnetic vector potential and a two dimensional (2-D) polar system, analytical solutions for flux density due to permanent magnet (PM) and current are obtained. In particular, the analytical solutions for mathematical expressions of magnets with different circumferential thicknesses can be solved introducing improved magnetization modeling techniques. The analytical results are validated extensively be nonlinear finite element solutions, a reduction of torque ripple can be achieved.

• 한국산학기술학회논문지
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• 제12권9호
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• pp.4083-4094
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• 2011

전기식 파워 스티어링(EPS)은 유압식 파워스티어링에 비해 연비가 높고 스티어링 느낌이 좋으며 체적이 작으므로 자동차에 많이 적용되고 있다. 몇 년 전까지 대부분의 EPS 시스템에는 제어가 쉽고 하드웨어 구조가 간단한 영구자석 DC 모터가 주로 적용되었으나 최근에는 효율이 높고 수명이 긴 BLAC 모터가 적용되고 있다. 본 논문에서는 최근에 발표된 논문들을 기초로 EPS 시스템의 구조 및 BLAC 모터와 제어기술에 대해 고찰한다. 또한 스티어링 느낌을 좋게 하기 위한 토크리플 저감 및 안전을 위한 고장검출 알고리즘에 대해서도 검토한다.