• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1180-1182
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• 2005

In this paper, the design and field analysis of the novel axial flux type permanent magnet(AFPM) motor with double stator and single rotor are investigated. The various design schemes of AFPM based on 3D finite element method are proposed. The effects of slot shapes, various magnetization of PM, and skewing on the cogging torque and average torque have been investigated in detail. From the results, we can improve the cogging torque and average torque characteristics.

• 한국자기학회지
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• 제20권2호
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• pp.61-67
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• 2010

근래 첨단 전동기 개발에 고성능 영구자석이 적용됨에 따라 소형 전동기의 고출력화가 가능해진 반면 전동기의 진동과 소음이 커져 그 원인이 되는 코깅 토크에 대한 연구가 필요하게 되었다. 영구자석 전동기의 코깅토크는 영구자석에 의한 자계의 분포에 기인하게 되는데, 전동기의 자계 분포는 코어의 형상에 기인하므로 코어의 형상을 적절하게 설계함으로써 코깅토크를 저감시킬수 있다. 본 논문에서는 영구자석 전동기의 코깅토크를 저감하기 위한 기존의 sub-slot 법을 개선하여 보다 단순화 한 형상으로 코어의 설계변수를 대폭 줄임으로 효과적으로 코깅토크를 저감할 수 있는 기법을 제안하고 이를 영구자석 전동기에 적용하여 기존의 대표적인 sub-slot 법과 비교하고 그 성능을 검증하였다.

• 전기학회논문지
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• 제65권12호
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• pp.2183-2188
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• 2016

This paper deals with the design process for an outer-rotor-type surface-mounted permanent magnet synchronous motor (SPMSM) used in continuous variable valve timing (CVVT) systems in automobiles with internal combustion engines. When the same size, outer-rotor-type SPMSMs generate larger torque and more stable than inner-rotor-type SPMSMs. For the initial design, space harmonic analysis (SHA) is used. In order to minimize the cogging torque, an optimization was conducted using Response Surface Methodology (RSM). At the end of the paper, Finite Element Analysis (FEA) is performed to verify the performance of the optimum model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.202-205
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• 2008

This paper presents an optimization of permanent magnet (PM) in a brushless dc (BLDC) motor using the response surface methodology (RSM). Size and angle of the PM are optimized to minimize the cogging torque, while reducing the magnitude of harmonic at a dominant frequency and maintaining the operating torque. A fitted RS model is constructed by verifying the high reliability of the total variation and the variation of estimated error. The optimized design is validated by carrying out the reanalysis and comparing to the initial model using the nonlinear transient finite element analysis.

• Journal of Electrical Engineering and Technology
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• 제5권3호
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• pp.462-467
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• 2010

This paper presents the rotor shape optimization of an interior type permanent magnet (IPM) motor for a reduction of vibration and Electromagnetic Interference (EMI). The vibration and EMI in permanent magnet motors is generated by cogging torque ripple, radial force and commutation torque ripple. Consequently, in order to improve vibration and EMI, the optimal notches are put on the rotor pole with an arc shape proposed. The variation of vibration frequency due to the cogging torque and radial force of each model is computed by the finite element method (FEM). From the analysis result and experiment, we confirmed the proposed model has remarkably improved the vibration and EMI.

• 조명전기설비학회논문지
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• 제27권8호
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• pp.36-41
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• 2013

This paper is development of single-phase brushless DC motor with outer rotor for ventilation fan. Cogging torque causes the noise vibration to greatest impact on ventilation fan. Asymmetric notches are applied to tapered-teeth for cogging torque reduction of single-phase brushless DC motor. Initial model is notchless and proposed model is applied 2 asymmetric notches. The proposed method is proved motor characteristic through finite element analysis(FEA). Also, experimental results verify that the proposed model considerably reduces cogging torque and have the good sound quality in ventilation system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.58-62
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• 1990

Air gap flux density is obtained strictly from air gap permeance and MMF distribution using the design parameter of BLDCM when the stator slot is considered. Then the theoretical equations representing the cogging torque and BEMF are proposed. The effect of skew is described analytically, and skew effect on air gap permeance and MMF is studied. Consequently we verified analytically that skew of slots and magnets influenced on the reduction of the cogging torque and BEMF ripple, and the shape of BEMF.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.140-142
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• 2006

Cogging torque is often a principal source of vibration, noise and difficulty of control in permanent-magnet brushless DC motors. Cogging torque can be minimized by sinusoidal air-gap flux density waveform because it is produced by the interaction of the rotor magnetic flux and angular variation in the stator magnetic reluctance. Therefore, this paper will present a design method of magnetization system of bonded isotropic neodynium-iron-boron(Nd-Fe-B) magnets in ring type with sinusoidal air-gap flux density distribution and low manufacturing cost. An analytical technique of magnetization makes use of two-dimensional finite element method(2D FEM) and Preisach model that expresses the hysteresis phenomenon of magnetic materials in order for accurate calculation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.67-69
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• 1998

The cogging torque in the small BLDC motors used in the DVD driving system or HDD driving system can cause some serious vibration problem. In this paper, some core shapes that reduce cogging torque are found by using reluctance network method(RNM) for magnetic field analysis and genetic algorithm(GA) for optimization. The outer rotor type BLDC motor for the DVD ROM driving system has been optimized as an sample model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.891_892
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• 2009

This paper presents the rotor study on the deal with the shape design with a flux barrier to minimize the cogging torque of Interior Permanent Magnet Synchronous Motor(IPMSM). In order to consider the notch effect, the torque characteristics according to the shape of notch is performed and analyzed. From the this results, we found that an optimal location and radius of the notch effectively suppresses the torque pulsation of the IPM drive. The rotor shape design also shows improvement in the average torque