• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.245-249
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• 2009

Antarctic King Sejong Station was established in King George Island, the South Pole in 1988, and has been executing the monitoring studies on the change of antarctic natural environment. As an available power, the wind energy generator has been used in the form of hybrid with mainly diesel generator. Because the wind generation power sharply changes by wind energy, it must be careful during the system operation. When the power system becomes stable, the output performance of wind energy generator becomes stable. But, in case of unstable system, the errors frequently occur on the wind energy generator and it badly impacts the power system by output of wind energy generator. The purpose of this paper is to analyze suitability while operating the system of 10kW wind energy generator at Antarctic King Sejong Station, an isolated area, and to analyze the problem and improvements by power quality.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권2호
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• pp.77-83
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• 2000

This paper deals with the design of a touch free eddy-current brake for high speed transportation systems by using 2-dimensional Finite Element Method (2-D FEM). The eddy current brake systems have to equipped with maximum braking force and deceleration at the given volume or mass, high braking force at small rate, attraction forces as small as possible and stable construction. The parameters, such as the number of pole, electric ampere-turns and slot width have influence on these braking characteristics. For the magnet to satisfy above-mentioned performance in high speed, the braking performance according to variation of the parameters are analyzed by the 2-D FEM. In addition, the magnet stack width is determined from equivalent stack width that is calculated by solution of the Field with scalar potential. From these results, the magnet of optimized configuration with maximum braking force and minimum attraction force is designed by the process of detail design.

• 한국전기전자재료학회논문지
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• 제23권5호
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• pp.408-412
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• 2010

The single-phase switched reluctance motor(SRM) generates the positive torque in the restricted section. So, it can not started by itself and the torque ripple is heavier than poly-phase. For self-starting and fixing rotating direction, the rotor should be placed at the rising inductance slope when stationary. The parking permanent magnet locates the rotor in the fixed position, which can be started by it-self. It is very simple and cost effective but has some drawbacks. It affects the rotor during the operation, so the characteristics of motor, such as a torque, speed, and ripple are changed to go bad. This paper presents the detent torque of parking magnet starting device through the finite element analysis and experiments. The finite element analysis is performed at incremental rotor positions over one detent torque cycle for any one pole. The prototype, fabricated in the previous research, is used for the experiments. The inductance, instant torque, and detent torque are calculated using the terminal voltage and phase current. Finally, the finite element analysis result and the experiment result are compared for analysis and validity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.55-57
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• 2002

In industry, A pallet truck is drived mainly by d.c motor, because it use to battery for input power. However, d.c motor has a brush, this is the disadvantage of the d.c motor for a pallet truck. Though a brushless d.c motor has a permanent magnet, it is for low torque. Switched reluctance motors(SRM) have the advantage a high torque/weight ratio, as the large reluctance torque is made by salient poles of both start and rotor, and a high reliability, this paper design the shape of the switched reluctance motor that will replace a d.c motor for A pallet truck. First of all, designed parameter of SRM, outer diameter, diameter of rotor and stock length, from the outputr equation considering electric loading and magnetic loading. Next, design diameter of stator and rotor, depth of slot pole width, air gap as inner size of motor. The design of SRM certify the torque, the efficiency and the output power by a simulation.

• Progress in Superconductivity
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• 제3권1호
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• pp.95-98
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• 2001

Recently, NiO films have been studied as a buffer layer to fabricate the superconductor with preferred orientation and as a diffusion barrier to prevent the reaction between superconductor and textured nickel substrate . We fabricated NiO films on textured Ni substrate by thermal oxidation with various variables of temperature, oxidation time, atmosphere, and cooling rate. We investigated the alignment of NiO films by XRD and pole figure and the microstructures by SEM. (200) <001> alignment of NiO film was observed at the oxidation condition of $1200^{\circ}C$ far 10min and slow cooling in O2 atmosphere. During the process in Ar atmosphere, we could also observe the thermal faceting which affects the alignment of NiO alms on Ni substrate.

• 한국정밀공학회지
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• 제31권6호
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• pp.543-550
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• 2014

A magnet gear composed of two layers of permanent magnets repeated circumferentially can transmit the power without mechanical contact. In the topology called by the magnet shutter gear known as the most competitive concept among the existing concepts, the number of pole-pairs on the high speed rotor corresponds to that of low speed rotor through electric steel set functioning as a magnetic modulator. The methodology is classified into radial type and axial type according to its magnetic path as in the motor. However, the magnetic modulator has multiple poles located separately. So, it is very complicated to assemble each module of the magnet gear mechanically and to sustain a mechanical stiffness of the modulator. The practical trouble can be solved partially through reconfiguring the modules. This paper deals with the novel magnetic shutter gear topology varying the magnetic path and its effectiveness is verified through real hardware implementation.

• Journal of Electrical Engineering and Technology
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• 제2권1호
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• pp.55-60
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• 2007

This paper proposes a hydraulic pump system that uses a variable speed SR drive and constant capacity pump. For the design of the SRM (Switched Reluctance Motor) and digital controller, base speed and rating torque are determined from the mechanical specifications of the hydraulic pump. In order to minimize the power consumption during the maintaining of preset oil-pressure, the pressure control system changes the maximum oil-pressure band and flow rate according to the motor speed. The DSP control system adjusts the oil-pressure and the speed of the SRM from the pressure sensor signal, due to conservation of power consumption by the hydraulic pump. A 2.2Kw, 12/8 pole SR motor and DSP based digital controller are designed and tested with experimental set-up. The test results indicate that the system has some good features such as high efficiency and rapid response characteristics.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.363-368
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• 2013

영구자석형 동기전동기에 벡터제어를 적용하여 정지시까지 전기제동을 하였으며, 속도검출기는 레졸바를 사용하여 제어기에서 관측자에 의한 위치와 속도를 추정하는 방식을 제안하였다. 또한, 정지직전의 극저속에서 속도에 의한 제동 토오크를 제어하는 방법으로 정지시까지 전기제동을 하였다. 그 결과 제륜자의 소모율 저감과 유지보수성을 증대시키고 소음 및 분진발생의 저감, 승차감과 에너지 사용효과를 향상시켜 전동차의 성능을 향상 시켰음을 알 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.380-383
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• 2014

허브(hub) BLDC(Brushless Direct Current) 전동기란 아우터로터 타입 고효율 전동기로 다극의 영구자석으로 이루어진 회전자가 바퀴의 구동축이 되는 직접구동용 모터를 말하며, 휠인 모터로도 불린다. 본 연구에서는 BLDC 허브 모터 구동을 위한 벡터제어 기법 속도 제어기를 dsPIC30f2010 16비트 마이크로 컨트롤러를 이용하여 설계한다. 특히 복잡한 연산 시간을 줄이는 벡터 제어 방법을 제안하고, MOSFET 인버터 구동기를 직접 설계하여 경제성을 높인다.

• 한국융합학회논문지
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• 제12권12호
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• pp.273-280
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• 2021

본 연구는 하이브리드 자동차의 리니어 오실레이팅 전기기기의 비교 연구를 위해 수행하였으며, 다섯 가지(직각좌표형, 영구자석 매입 원통형, 자속역전식, 릴럭턴스 원통형, 횡자속 형태.)의 제안된 형태의 비교를 통해 리니어 오실레이팅 전기기기의 연구결과를 제시하였다. 모든 형태는 초기 모델링으로서 누설을 고려한 등가자기회로법을 통해 수행되었다. 영구자석 형태의 이동자로 구성된 직각좌표형은 구속조건 아래에서 설계변수들의 파라미터 분석을 통한 최적화 과정이 수행되었고, 영구자석 매입 원통형은 이동자에 영구자석과 Back-iron이 결합된 구조를 제시하였다. 자속역전식은 영구자석형 이동자의 매입형태에 따른 분석과 향상된 모델을 제시하며, 릴럭턴스 원통형은 유효 자속의 증가와 리플을 저감하기 위한 이동자 치의 형태를 비교·분석하였다. 횡자속 형태에서는 2차원 분석기법과 3차원 분석을 통한 비교를 수행하였다. 본 연구는 설계 규칙과 리니어 오실레이팅 전기기기의 특성을 제공한다는 측면에서 의미가 있다.