• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.7-13
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• 2015

This paper presents mathematical models for high speed permanent-magnet synchronous machine. The mathematical method with two successive steps is used to estimate design parameter as well as the output power. At first, mathematical model for a linkage flux problem is employed to calculate the number of winding turns and stack length of armature core. The magnetic circuit model for an induced voltage and the electric circuit model for a current are modeled. The output powers of the electrical generator were evaluated by the mathematical techniques. The results of this mathematical methods predict the specifications of the machine and can be applied in the design stage of the electrical machine.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.105-110
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• 2009

Distributed Generation (DG) is predicted to play a important role in electric power system in the near future. insertion of DG system into existing distribution network has great impact on real-time system operation and planning. It is widely accepted that micro turbine generation (MTG) systems are currently attracting lot of attention to meet customers need in the distributed power generation market In order to investigate the performance of MT generation systems, their efficient modeling is required. This paper presents the modeling and simulation of a MT generation system suitable for grid-connected operation. The system comprises of a permanent magnet synchronous generator driven by a MT. A brief description of the overall system is given, and mathematical models for the MT and permanent magnet synchronous generator are presented. Also, the use of Power electronics in conditioning the power output of the generating system is demonstrated. Simulation studies with MATLAB/Simulink have been carried out in grid-connected operation mode of a DG system. The control strategies for grid connected operation mode of DG system is also presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.210-216
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• 2009

Distributed Generation (DG) is predicted to play a important role in electric power system in the near future. insertion of DG system into existing distribution network has great impact on real-time system operation and planning. It is widely accepted that micro turbine generation (MTG) systems are currently attracting lot of attention to meet customers need in the distributed power generation market. In order to investigate the performance of MT generation systems, their efficient modeling is required. This paper presents the modeling and simulation of a MT generation system suitable for stand-alone operation. The system comprises of a permanent magnet synchronous generator driven by a MT. A brief description of the overall system is given, and mathematical models for the MT and permanent magnet synchronous generator are presented. Also, the use of power electronics in conditioning the power output of the generating system is demonstrated. Simulation studies with MATLAB/Simulink have been carried out in stand-alone operation mode of a DG system.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.527-536
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• 2014

In this paper, the 50kW aerogenerator which is applicable to the microgrid was designed and analyzed by using commercial simulation program Maxwell 2D. Particularly, the suggested PMSG to reduce the cogging torque introduced the offset and skew concept. The suggested optimal value of offset and skew was decided by 2mm and 60 degree of electric angle. The simulation results of the PMSG when load operation condition showed the average harmonic distortion 1.3%, voltage 322.41V, current 94.95A, and iron loss 9.73W, eddy current loss 73.68W, copper loss 3.52kW. The capacity of aerogenerator calculated 61.56kW, and the suggested design process can be applied to higher capacity generator.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.122-122
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• 2022

기후변화 대응 및 탄소 저감 노력의 일환으로 신재생에너지의 개발 및 활용이 전 세계적으로 활발하며, 우리나라에서도 2050년 탄소중립 달성을 위하여 친환경 에너지 시스템 구축에 많은 노력을 기울이고 있다. 전통적인 재생에너지인 수력은 발전의 효율성, 안정성과 발전 제어의 용이함 때문에 널리 사용되고 있으나, 경제성을 확보하기 위한 댐, 보의 설치 및 대규모 발전설비가 필요하여, 생태계, 환경 파괴 등의 문제점 등을 수반하여, 최근 들어 대규모 사업이 이루어지지 못하고 있다. 이러한 흐름에 따라 최근에는 유럽을 중심으로 친환경 소수력 발전으로 회전 나선형 아르키메데스 수차를 활용한 소수력 발전의 적용이 이루어지고 있으며, 특히 2000년대 이후 독일을 중심으로 활발히 개발되고 있다. 또한 휴대용 초소수력 발전은 새로운 산업분야로 민간용 초소수력 발전기의 개발 및 판매가 국내외에서 증가하고 있으며, 우리나라에서도 자연 하천 환경에 활용 가능한 초소수력 발전의 필요성이 꾸준히 제기되고 있다. 본 연구에서는 저유량 및 저낙차에 적용 가능한 '초소형 회전 나선형 아르키메데스 수차', 초소형 발전에 적합한 '발전기 및 발전시스템', 자연환경을 훼손하지 않는 친환경 '유도수로'로 구성되어, 원하는 하천이나 수로 등에 손쉽게 설치 가능한 초소형 소수력 발전시스템을 개발하였다. 회전 나선형 아르키메데스 수차는 3D프린터로 제작한 후, 강화 코팅제를 도포하여 내구성을 확보하였다. 상용 AC발전기, 소형 발전기용 '발전기 및 발전시스템'을 적용하고, 콘트롤 보드를 맞춤형으로 제작하여 경제성을 확보하였다. 이러한 발전 시스템은 개발 테스트 중에 있으며 향후 방류수로, 하수구 등 현장 적용을 준비 중에 있다.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.23-28
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• 2002

This paper describes the machining characteristics of the $MoSi_2$ based composites by electric discharge drilling with various tubular electrodes, besides, Hardness characteristics and microstructures of $Nb/MoSi_2$ laminate composites were evaluated from the variation of fabricating conditions such as preparation temperature, applied pressure and pressure holding time. $MoSi_2$ -based composites has been developed in new materials for jet engine of supersonic-speed airplanes and gas turbine for high- temperature generator. Achieving this objective may require new hard materials with high strength and high temperature-resistance. However, With the exception of grinding, traditional machining methods are not applicable to these new materials. Electric discharge machining (EDM) is a thermal process that utilizes a spark discharge to melt a conductive material, the tool electrode being almost non-unloaded, because there is no direct contact between the tool electrode and the workpiece. By combining a nonconducting ceramics with more conducting ceramic it was possible to raise the electrical conductivity. From experimental results, it was found that the lamination from Nb sheet and $MoSi_2$ powder was an excellent strategy to improve hardness characteristics of monolithic $MoSi_2$. However, interfacial reaction products like (Nb, Mo)$SiO_2$ and $Nb_2Si_3$ formed at the interface of $Nb/MoSi_2$ and increased with fabricating temperature. $MoSi_2$ composites which a hole drilling was not possible by the conventional machining process, enhanced the capacity of ED-drilling by adding $NbSi_2$ relative to that of SiC or $ZrO_2$ reinforcements.