• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.127-127
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• 2012

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.304.2-304
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• 2002

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.85-91
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• 2009

This paper proposes a simulation method of the internal winding fault to calculate the short-circuit current, electromagnetic force and vibration mode in a distribution power transformer by using FEM program(FLUX2D) and analytic algorithm. A usage of the Transfer matrix method is also presented for the vibration mode analysis of the cable-type winding of power transformer. The equations of the winding are approximated by the series expansions of the distributed mass mode and Timoshenko's beam theory. The simulation examples are provided for the cable type winding of the transformer(22.9[kV]/220[V], 1,000[kVA]) to verify the method. The proposed Transfer Matrix Method is also verified by the ANSYS program for the vibration mode of the transformer winding. The method presented may serve as one of the useful tools in the electromagnetic force and vibration analysis of the transformer winding under the short circuit condition.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.104-106
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• 2006

Slotless BLDC motor는 Slot과 Teeth가 없으므로 이에 따른 Cogging Torque 및 Torque Ripple이 거의 존재 하지 않으며, 전동기의 무게 또한 감소하게 된다. 또한 권선의 장주(Span)가 짧아 Inductance가 낮기 때문에 고속화가 용이해지며, Slot의 부재는 좀 더 많은 Coil권선을 이용 할 수 있다. 하지만 모터의 구조상 전기장하가 높아짐에 따라 권선의 온도 상승에 대한 보완 등이 필요로 되어 지고 있다. 따라서 본 논문에서는 온도 상승 문제를 해결하기 위해 열 발생과 모터사이의 관계 규명을 전류 밀도 함수로 표시 하였고, 전류 밀도 최소화 설계 방법을 제안하였다. 퍼미언스법에 의한 간략 설계에 의해서 기본 설계를 실시 한 후 FEM을 통한 정밀 해석을 통해서 각각의 민감도를 분석하여 최적의 파라메타를 선정하는 방식을 취하였다. 또한 고속 회전시 발생되는 진동을 저감하기 위해 모터의 길이방향 즉 적층과의 관계를 통하여 진동 저감 설계를 제안하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.1
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• pp.53-58
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• 2001

The main noise sources in SMPS are divided into three parts: the switching devices, the rectifiers in secondary part, the output transformer and choke coil. In this paper we performed the noise analysis with respect to bobbin type and winding method, and designed an optimized transformer focusing on the transformer. For the comparison. we measured four parameters for each cases, including EMI conducted emission noise. signal from the switching devices, output ripple/noise voltage and leakage current. As the result, the transformer using a vertically-typed bobbin and a parallel, sandwich winding method showed the best performance. We confirmed that the SMPS developed in this research is satisfied with the IEC 601-1 international standard for the medical instrumentation. by testing its electrical characteristics and safety.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.492-492
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• 2013

반도체 공정을 위한 원격 유도 결합 플라즈마(remote ICP)에서 플라즈마 균일도를 향상하는 연구를 진행하였다. 본 연구에서는고 균일도 플라즈마 발생을 위해 단면적이 다른 2개의 반응 용기를 상부와 하부에 설치하였으며, 각각의 반응 용기 외곽에 방전 코일이 위치하도록 구성하였다. 상부의 반응 용기는 외곽에 유도 코일을 권선하였고, 하부의 반응 용기는 고밀도의 플라즈마 생성을 위해 강자성체를 이용하여 권선하였으며, 강자성체는 쿼츠관을 둘러 싼 구조로 되어 있다. 0.5-1 Torr 공정 압력 범위의 아르곤 기체에서 전체 2500 W의 전력을 인가하였고, 임피던스 정합회로로부터 각각 병렬로 연결된 방전 코일에 전력이 분배되어 인가되는 구조로 설계하였다. 반도체 공정을 위한 플라즈마 균일도를 분석하기 위해 wafer의 위치에서 부유 탐침법을 적용하여 wafer 중심부로부터 반경 방향으로 위치를 변화시키며 플라즈마 밀도와 전자온도를 측정하였다. 동일한 공정 조건에서 하부에 강자성체를 사용하여 권선한 이중 구조의 경우 하나의 방전 코일을 이용한 구조 대비 플라즈마 밀도가 증가하였고, 플라즈마 균일도가 크게 향상됨을 보였다. 강자성체를 이용한 하부 코일에 의해 wafer 외곽 부분의 밀도가 높은 분포를 갖는 플라즈마가 형성되고, 상부의 유도코일에 의해 wafer 중심부에 밀도가 높은 플라즈마가 형성되어 wafer의 플라즈마 균일도가 개선된다. 또한, 강자성체를 이용한 하부 코일에 의해 고밀도의 플라즈마가 형성되므로 반도체 공정을 위한 장비에서 플라즈마 균일도의 개선과 밀도의 향상으로 대면적 Dry Strip 공정 (450mm)에 적용 가능하다.

• Journal of the Korean Magnetics Society
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• v.25 no.2
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• pp.58-65
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• 2015

This paper deals with the generating characteristic analysis of permanent magnet linear generator (PMLG) with double-sided Halbach magnet array mover and three phases concentrated stator windings by using analytical method. On the basis of a magnetic vector potential and Maxwell's equations, governing equations are obtained, and magnetization modeling for Halbach magnet array is performed analytically by using the Fourier series. And then, we obtain electrical parameters such as back-EMF constant, resistance, and coil inductance based on magnetic field calculations. Finally, analytical results for generating performance are confirmed by comparing with finite element analysis results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.64-72
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• 2002

The use of linear DC motor is spreaded according to industrial development. This study was objected to study the analysis of double side excitation LDM with moving magnet type. In this LDM structure, the mover made use of permanent magnet with six pieces so as to large thrust, the stator was bedded for the multi separated type winding to repress the i개n saturation. Also, double side excitation winding is suppressed to thrust ripple with stratification to zigzag type and designed to production for static thrust. Then it is important to ratio of permanent magnet to winding width at multi separate, this paper analyzed to separate to three pieces of 1:1, 1:0.84 and 1:0.5 with width ratio. The analysis method calculated the parameter useful for permeance and magnetic resistance more than FEM of complicated numerical value analysis. Through manufactured experiment system, measurement result of thrust was almost acquired to constant thrust for all displacement.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.351-358
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• 2003

This paper describes distribution characteristics of switching surge voltage in stator windings of induction motor driven by IGBT PWM inverter. To analyze the voltage distribution between the turns and coils of stator winding, equivalent circuit model of induction motor including cable was proposed and high frequency parameter is computed by using finite-element method (FEM). From the electro-magnetic transient program (EMTP) simulation of the whole system for induction motor, feeder cable, and PWM inverter, the variable effect on rising time of the inverter, cable length, and switching frequency on the voltage distribution is also presented. In order to experiment, an induction motor, 380[V], 50[HP], with taps from one phase are built to consider the voltage distribution so that these results can be helpful when filter was designed to remove high dv/dt.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.3
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• pp.167-178
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• 2010

To diagnose a stator winding fault caused by a short-circuited turn in a permanent magnet synchronous motor (PMSM), an on-line based fault detecting scheme during motor operation is presented. The proposed scheme is based on monitoring the second-order harmonic components in q-axis current obtained through the harmonic analysis and a winding fault is detected by comparing these components with those in normal conditions. The linear interpolation method is employed to determine harmonic data in arbitrary normal operating conditions. To verify the effectiveness of the proposed fault detecting scheme, a test motor to allow inter-turn short in the stator winding has been built. The entire control system including harmonic analysis algorithm and fault detecting algorithm is implemented using DSP TMS320F28335. The proposed scheme does not require any additional hardware and can effectively detect a fault during motor operation so long as the steady-state condition is satisfied.