• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.824-827
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• 2003

Recently, Development of Rare Earth Permanent magnet with the high remanence, high coercivity allow the design of brushless motors with very high efficiency over a wide speed range. Cogging torque is produced in a permanent magnet by magnetic attraction between the rotor mounted permanent magnet and the stator teeth. It is an undesired effect that contributes to the machines output ripple, vibration, and noise. This cogging torque can be reduced by variation of magnet arc length, airgap length, magnet thickness, shifting the magnetic pole and varying the radial shoe depth and etc. In this paper, Some airgap length and magnet arc that reduce cogging torque are found by FEM(Finite element method). The SPM type of high-capacity BLDC motor is optimized as a sample model.

• Journal of Electrical Engineering and Technology
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• 제6권3호
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• pp.356-363
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• 2011

Vibrations and noise in electrical machines are directly related to the characteristics of the radial forces on one hand, and mechanical behavior on the other [1, 4]. The characteristics of these forces depend on the air gap flux density, which is also influenced by other factors, such as stator slots and poles, saturation level, winding type, and certain faults. The aim of this work is to investigate the effect of eccentricity and demagnetization faults on electromagnetic noise generated by the external surface of Permanent Magnet Synchronous Machine [PMSM]. For this purpose, an analytical electromagnetic vibroacoustic model is developed. The results confirm the effect of eccentricity and demagnetization fault in generating some low modes radial forces.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.873-875
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• 2000

The self- and mutual- winding inductances can have an important influence on both the steady-state and transient dynamic performance of a machine. Especially, slotless topologics have inherently low self- and mutual-stator winding inductance. Thus, this paper describes an analytical model for predicting the winding inductance and results are compared to finite element analyses.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.650-652
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• 2000

Proposed slotless PM machine is constructed without stator winding slots. Its stator magnetic material is in the form of a ring and winding have a toroidal configuration and its rotor consists of a 4-pole Halbach array or radially magnetized PM rotor. Thus, airgap flux density distribution and induced emf waveform are essentially sinusoidal. Open circuit magnetic fields and developed torque of each type are presented from the analytical method and finite element method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.337-339
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• 2001

High speed brushless permanent magnet (PM) machines are a key technology for electric drives and motion control systems for many application, since they are conductive to high efficiency, high power density small size and low weight. Proposed slotless PM machine is constructed without stator winding slots. Its stator magnetic material is in the form of a ring and winding have a toroidal configuration and its rotor consists of a 4-pole Halbach array or radially magnetized PM rotor.

• 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.

• Journal of Magnetics
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• 제21권4호
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• pp.537-543
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• 2016

Currently, an interest in electric vehicles (EVs) exhibited by automakers, government agencies and customers make it as more attractive research. This is due to carbon dioxide emitted by conventional combustion engine that worsens the greenhouse effect nowadays. Since electric motors are the core of EVs, it is a pressing need for researchers to develop advanced electric motors. As one of the candidates, switched flux machine (SFM) is initiated in order to cope with the requirement. This paper proposes a new alternate circumferential and radial flux (AlCiRaF) of permanent magnet switched flux machines (PMSFM) for light weight electric vehicles. Firstly, AlCiRaF PMSFM is compared with the conventional PMSFM based on some design restrictions and specifications. Then the design refinements techniques are conducted by using deterministic optimization method in order to improve preliminary performance of machine. Finally the optimized machine design has achieved maximum torque and power of 47.43 Nm and 12.85 kW, respectively, slightly better than that of conventional PMSFM.

• 전력전자학회논문지
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• 제14권2호
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• pp.105-111
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• 2009

현재 생활의 이기인 자동차 등에서 구동되는 기기의 전원은 배터리 전원을 주로 사용하고 있으며, 또한 산업체에 사용되는 인버터를 사용하는 기기에서도 DC 전원 사용이 확대되고 있다. 이와 같이 DC 전원이 사용되는 곳에서 전력선을 활용한 데이터 통신방식에 대한 수요가 급증할 것으로 사료된다. 본 논문에서는 DC 전원을 기반으로 하는 DC 전력선 통신을 이용하여 BLDC(Brushless DC) 전동기 구동시스템을 제안한다. 이 시스템의 특징은 인출되는 DC 전원으로 사용되는 2 선만으로 구성하여 데이터 통신을 할 수 있는 장점이 있다. 외부 설정치와 지령치로 사용되는 신호선을 제거하고 전력선과 엔코더 신호선의 단축으로 신뢰성 확보되며, 또한 멀티 제어 시 배선수의 최소화 및 회전기기 장착 시 슬립링 수를 최소화 할 수 있다. 위험한 환경에서도 안정성이 증가되며, 시스템 제작단가를 저감할 수 있다. 마지막으로 제안된 방식에 대한 우수성을 검증하기 위해서 PSIM 및 MATLAB를 활용하여 시뮬레이션을 실시하였고, 실제 프로토타입을 제작하여 실험을 통하여 그 타당성을 검증하였다.