• 한국유체기계학회 논문집
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• 제14권5호
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• pp.24-30
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• 2011

500W class MTG(Micro turbine generator) operating at 400,000 rpm is under development. From the cycle analysis, it is decided that the self-sustaining speed of MTG is 200,000rpm and the generating speed is 400,000 rpm. Therefore, motor should be designed so that it is able to rotate the rotor up to 200,000rpm and generator should designed so that it is able to generate 500W output at 400,000rpm. First step to design motor/generator is to determine the power and efficiency requirement. Not only the power into the compressor and from the turbine at the operating speed but also the mechanical and electrical losses should be considered in determining the power and efficiency requirement. This study presents the procedure and the results of determining the power and efficiency requirement considering the mechanical and electrical losses depending on the rotating speed which is measured from the experiment.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.456-459
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• 2009

we studied a data acquisition and control system of a wind turbine for measuring and controlling a voltage fluctuations of a wind turbine system. The wind turbine system is installed out control area. So, it is so important for supervising to wind turbine of a maintenance, wind speed, optical resources wind turbine output, wind speed, wind direction, over voltage of a generator. This system can be supplied a data of over voltage, under voltage, voltage fluctuations of a wind turbine for controlling an EMS : Energy Management System or a SCADA : Supervision Control and Data Acquisition at a constitute of a wind farm. The of voltage fluctuation system of a wind turbine is improving an electric power supply power quality of a distribution line and unspecified individuals of used wind turbine.

• 산업기술연구
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• 제24권B호
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• pp.83-87
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• 2004

A reduced structure model of a wind turbine generator is designed and manufactured. Mode data are obtained by modal testing and analytical method. Vibration response is measured and investigated under various speed condition by using a waterfall plot. Possibility of severe resonance is observed and the mechanism is explained by using the mode data. Simplified theoretical model gives the 1st resonance frequency of wind turbine structure model. The theoretical model can be applied in the design stage of the wind turbine structure to avoid the severe resonance problem.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.180-183
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• 2008

This paper is about the ocean current power generation using sea water incoming into the lake surrounded by barrages and sea water discharged from a dam made of artificial structures. In operation of a tidal power plant, the sea water discharged from a turbine structure and a gate structure of a tidal power plant is faster than the tidal current caused by tides in nature and has better characteristics than that to run ocean current turbines. It is shown that the sea water discharged after generating electricity through a turbine generator of a tidal power plant and the sea water discharged from a gate structure of a tidal dam still have kinetic energy high enough to run an ocean current turbine and produce valuable electricity.

• 한국유체기계학회 논문집
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• 제16권6호
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• pp.5-11
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• 2013

Torque control methods of wind turbine are mainly classified into two methods: torque-mode and speed-mode methods. The traditional torque-mode method, in which generator torque proportional to square of generator speed is determined, has been chosen in many wind turbines but its response is slower as they are larger in multi-MW size. Torque control methods based on both speed-mode and torque-mode can be used to make response of wind turbine faster. In this paper, two torque control methods based on the traditional torque-mode method are applied to a 2.75 MW wind turbine. It is shown through some simulation results for real turbulence wind speeds that torque control method based on torque-mode has the merit of reducing fluctuations of generated power than PI controller based on speed-mode.

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8753-8759
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• 2015

터빈 발전 사이클에서의 안정적인 발전 출력 유지관리를 위해서는 검증된 성능 측정 데이터 그룹과 이를 바탕으로 한 발전 출력 성능 계산 절차의 수립이 필요하다. ASME PTC(Performance Test Code)의 성능 계산 절차를 기반으로 본 연구에서는 터빈 출력에 의한 발전기 출력 성능 산정을 위해서 터빈 팽창선 모델과 발전기 출력 측정 데이터의 입력 검증 모델을 구성하였다. 또한 불확실한 측정 데이터에 대한 검증 모델도 구성하였다. 지난 연구에서는 신경회로망과 커널 회귀의 학습 방법을 사용하였으나 본 연구에서는 미측정 데이터에 대한 보완을 하기 위하여 서포트 벡터 머신 모델을 사용하여 발전기 출력 계산 데이터의 학습 모델을 구성하였으며, 학습 모델 구성을 위해서 관련 변수의 선정을 위한 절차와 학습 데이터 구간을 설정하는 알고리듬을 개발하였다. 학습의 결과 오차는 약 1% 범위 안에 있게 되어 추정 및 학습 모델로서 유용함을 입증하였다. 이 학습 모델을 사용하여 측정 데이터 중 상실된 부분에 대한 추정 모델을 구성함으로써, 터빈 사이클 보정 성능 계산의 신뢰성을 향상시킬 수 있음을 검증하였다.

• Journal of Magnetics
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• 제16권4호
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• pp.374-378
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• 2011

Axial Field Permanent Magnet (AFPM) generators are widely applied for the small wind turbine because of the higher power density per unit weight than that of the conventional radial field generator. It is caused by the disc shaped rotor and the stator structures. The generally used AFPM generator, AFER-NS generator, is composed of the two side's external rotors and non-slotted stator without stator core. However, the output voltage and the output power are limited by the large reluctance by the long air-gap flux paths. In this paper, the design study of AFIR-S generator having double side's slotted stator core is accomplished to improve the output generation characteristics. The electromagnetic design analysis and the design improvement of the suggested AFIR-S generator are studied. Firstly, the electromagnetic design analysis was done to increase the power density. Secondly, the design optimizations of the rotor pole-arc ratio of permanent magnet are accomplished to increase the output power and to reduce the cogging torque. Finally, the output performances of AFER-NS and AFIR-S generator are compared with each other. For this study, 3D FEA is applied for the design analysis because of three dimensional electromagnetic structures.

• 조명전기설비학회논문지
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• 제28권7호
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• pp.41-47
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• 2014

The on-line partial discharge (PD) in stator windings of air-cooled gas turbine (GT) generator (119.2MVA, 13.8kV) is measured and analyzed in this paper. This generator was designed by global vacuum pressure impregnation (VPI). The generator failed two times at top bar (16T) of phase B in the stator slot. Six epoxy-mica capacitors were installed in three phases of GT generator. On-line PD test was performed on GT generator using turbine generator analyzer (TGA). TGA showed that the normalized quantity number (NQN) and the PD magnitude($Q_m$) were high in phase B. Internal discharges were generated in phases A, B and C. The trend analysis of NQN and $Q_m$ value are obtained in order to monitor the insulation condition in GT generator stator windings. Phases A and C were in good condition. But phase B had deteriorated significantly

• 전기학회논문지P
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• 제63권2호
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• pp.74-80
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• 2014

Generator protection device has to detects an internal fault conditions in generator and abnormal operating conditions must be due to the hazards. Loss of excitation may cause generator itself failure as well as serious operating problem in power system, and then requires an appropriate response of generator protection device. Details modeling of generator control system and analysis of transient states in generator are important for optimal operation in power plants. In addition, the fault simulation data are also used for testing the characteristics of IED. In this paper, the hydro generator control system using PSCAD/EMTDC, visual simulation for power systems, was modeled. The generator control system which is composed of generator, turbine, exciter, governor was implemented. The parameters of generator control system model were obtained from field power plant. Loss of excitation simulations were performed while varying the fixed load. Several signals analysis were also performed so as to analyze transients phenomena.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.180.1-180.1
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• 2010

This paper introduces a 3MW embedded Permanent Magnet Synchronous Generator(PMSG) for wind turbine. The generator features 313mm stator inner radius and 974mm stator length. The blade rotor angular velocity is 15.7 rpm and the gear ratio is set to be 92.93. The nominal generator rpm at rated load is about 1459. The number of poles is six and embedded in the generator rotor. Embedded permanent magnet excitation shows higher reliability, and better efficiency. Using the finite element method, electromagnetic and thermal results are simulated by ANSYS and the results are summarized in this report.