• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.288-291
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• 2001

In steel plant, load torque of mill driver motor is changed periodically because working state and idle state are repeated and load current of working state is necessarily higher than rated motor current. The over current limiter is one of the basic thermal protection method from over heating. In this paper, we analyzed the structure of over current limiter for motor and motor driver systems, developed over current limiter with same operation and structured warning system of action of over current limiter. As using this warning system, we can avoid abrupt plant stop by over current limiter in mill driver and lessen producing loss by plant stop. The developed warning system of action of over current limiter is exactly inspected by computer simulation md analysis of acquired data.

• 조명전기설비학회논문지
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• 제26권1호
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• pp.61-65
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• 2012

Some works about the current sensorless control of a synchronous reluctance motor have been presented. However, there is no analysis about the performance and the detuning effect of the current sensorless control. This paper presents the problems and the detuning effect of the current sensorless control of a synchronous reluctance motor by simulation results. In addition, torque limiter is proposed to limit the torque current within the torque limit.

• Journal of Advanced Marine Engineering and Technology
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• 제38권3호
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• pp.262-268
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• 2014

본 연구는 2MW급 풍력 발전기용 고속커플링의 요구조건인 유연성과 절연성 및 과부하시 기능부품의 파손을 방지하기 위한 동력 차단기능을 만족하기 위한 구조설계와 검증에 관한 것이다. 커플링의 유연성과 절연기능은 강도와 유연성 및 절연성을 동시에 가지는 유리섬유강화플라스틱을 이용하여 설계하였으며 유한요소해석을 통하여 원소재 두께를 최적화하였다. 또한 이상 토크 발생시 동력전달을 차단하기 위한 토크리미터를 마찰차 형식으로 설계하였다. 시제품의 성능평가를 통하여 설계변수의 타당성을 검증하였다.

• 문화기술의 융합
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• 제5권4호
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• pp.361-366
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• 2019

환자를 위해 시트를 교환하는 일은 궂은일에 속하며 간호환경을 힘들게 하는 요인 중에 하나이다. 환자를 위한 다양한 기능들을 갖는 많은 침대들이 이미 개발되어 있으나 시트를 자동으로 교환하는 장치는 아직 없다. 본 연구에서는 의료용 침대를 위한 시트 자동 교환 장치를 최초로 개발하고 시험하여 성능을 검증하였다. 개발된 시트 자동 교환 장치는 토크 리미터를 사용하여 장력을 적절히 조절하며 오염된 시트와 새로운 시트를 동시에 교환한다. 설계된 시트 자동 교환 장치는 기 개발된 욕창 예방, 환자 자동 이송 기능을 갖는 다기능 통합 침대에 장착되어 적절히 동작하는 것을 실험을 통해 확인하였다

• 한국생산제조학회지
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• 제8권1호
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• pp.150-157
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• 1999

In this study, the loader was completed that has 4-wheel gear driven drivetrain of study (Ⅰ), the 4-wheel steering with power wheel type, all-wheel traction system, and joy-stick type lever for hydraulic control valve. From driving test of the developed 4WD and 4WS type loader, we obtained that the minimum circling radius and the necessary width in circling motion reduced about 40% and 33% compared with 2WS type loader. Also, all-wheel traction system could keep the tires glued to the ground with greater stability, the power steering allowed a smoother operation, and the joy-stick type lever offered easily to control. Thus, the developed loader having these functions was very fit in a small cattle shed or rugged ground.

• 대한전기학회논문지
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• 제35권9호
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• pp.396-402
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• 1986

Although the structure of the brushless DC motor is similar to the one of the permanent magnet synchronous motor, its operating characteristics are the same as those of the permanent magnet DC motor. This is the reason that the commutators and brushes in the permanent magnet DC motor can be replaced by the power semiconductor devices and rotor position sensors for the brushless DC motor. In this paper, a current control method is presented to make a sinusoidal current waveform for constant torque generation and the operating characteristics of the brushless DC motor using the resolver as the rotor position sensor is also presented and experimented.

• 풍력에너지저널
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• 제10권4호
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• pp.20-27
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• 2019

High-speed shaft coupling in a wind power system transmits power and absorbs variations in length and spindle dislocation between the gearbox and generator. Furthermore, the coupling has an insulation function that prevents electrical corrosion caused by the flow of the generator's current into the gearbox and prevents overload resulting from sudden power failure from being transferred to the gearbox. Its design, functions, and part verification are described in the IEC61400 and GL Guidelines, which specify that the part must have a durability life of 20 years or longer under distance variation and axial misalignment between the gearbox and the generator. This study presents the design of a high-speed coupling through composite stiffness calculation, structural analysis, and comparative analysis of test and theory to identify the characteristics of high-speed coupling for a large-capacity 6 MW wind power generator. A prototype was fabricated by optimizing the manufacturing process for each part based on the design, and the reliability of the fabricated prototype was verified by evaluating the performance of the target quantitative evaluation items.