• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.411-414
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• 2006

풍력 발전기의 블레이드는 다른 회전기와는 달리 항상 지면의 경계층, 요-에러에 의한 어긋난 유입류, 타워와의 간섭효과의 환경에서 운영된다. 따라서 정상운전상태에서도 이와 같은 환경에서 겪게 되는 공력하중의 해석이 블레이드의 설계에서 중요하게 요구된다. 본 연구에서는 이의 비정상 공력하중해석을 위하여 자유후류기법을 이용한 방법을 연구하였다. 특히, 타워와의 간섭해석을 위하여 FVE라 명명한 후류 모델을 개발하여 적용하였다.

• 한국전산유체공학회지
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• 제18권2호
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• pp.41-48
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• 2013

Ice accretion on the solid surface is an importance factor in assessing the performance of aircraft and wind turbine blade. Changes in the external shape due to ice accretion can greatly deteriorate the aerodynamic performance. In this study, a three-dimensional upwind-type second-order positivity-preserving finite volume CFD scheme based on the unstructured mesh topology is developed to simulate two-phase flow in atmospheric icing condition. The code is then validated by comparing with NASA IRT experimental data on the sphere. The present results of the collection efficiency are found to be in close agreement with experimental data and show improvement near the stagnation region.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.378-381
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• 2007

탄소섬유가 중앙에 적층된 풍력발전용 블레이드 소재인 탄소 유리섬유 하이브리드 복합재료가 VARTM(Vacuum Assisted Resin Transfer Molding)공법을 이용하여 제작되었다. 아이조드 충격시험법을 이용하여 온도, 하이브리드화 비율 그리고 노치에 대한 충격강도의 영향을 연구하였다. 온도 감소 및 탄소섬유의 증가에 의해 충격강도는 감소하는 경향을 보였으며, 노치에 의해 하이브리드 복합재료는 약 $25{\sim}30$%가량의 충격강도 감소를 보였다. 그러나 단일 탄소섬유 복합재료의 경우 노치민감도는 없었으며, 이에 소량의 유리섬유 첨가로 인해 하이브리드화 하였을 경우 충격강도 향상 및 저온 충격강도 안정성을 확보 할 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.382-385
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• 2007

The optimal design and characteristic analysis of Double Fed Induction Generator(DFIG) was performed. The purpose of the paper is to verify the accuracy of design and the reliability of DFIG by experiment. A grid connection experiment is performed to confirm generating performance in wide operating range. In this experiment, 2.7MW M/G set is used. The finite element method is applied to calculate parameters and characteristic analysis of DFIG. And in order to reduce design time and efforts, Design of Experiment(DOE) is used. The experimental results are compared with the optimum design results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.414-419
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• 2012

The evaluation of a zonal RANS-LES approach is documented for the prediction of broadband noise generated by the flow past unmodified and serrated airfoil trailing edges at a high Reynolds number. A multi-domain decomposition is considered, where the acoustic sources are resolved with a LES sub-domain embedded in the RANS domain. A stochastic vortex method is used to generate synthetic turbulent perturbations at the RANS-LES interface. The simulations are performed with a general-purpose unstructured control-volume code FLUENT. The far-field noise is calculated using the aeroacoustic analogy of Ffowcs Williams-Hawkings. The results of the simulation are validated through the full-scaled wind turbine acoustic measurements. It is found that the present approach is adequate for predicting noise radiation of serrated trailing edge flow for low noise rotor system.

• 한국소음진동공학회논문집
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• 제22권5호
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• pp.444-450
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• 2012

The evaluation of a zonal RANS-LES approach is documented for the prediction of broadband noise generated by the flow past unmodified and serrated airfoil trailing edges at a high Reynolds number. A multi-domain decomposition is considered, where the acoustic sources are resolved with a LES sub-domain embedded in the RANS domain. A stochastic vortex method is used to generate synthetic turbulent perturbations at the RANS-LES interface. The simulations are performed with a general-purpose unstructured control-volume code FLUENT. The far-field noise is calculated using the aeroacoustic analogy of Ffowcs Williams-Hawkings. The results of the simulation are validated through the full-scaled wind turbine acoustic measurements. It is found that the present approach is adequate for predicting noise radiation of serrated trailing edge flow for low noise rotor system.

• 한국해양공학회지
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• 제16권1호
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• pp.58-63
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• 2002

In this research, a design guideline of current generating HAT rotor and acceptable field rotor in offshore environment is proposed. To design HAT rotor model, wind mill rotor design principles and turbine theories were applied based on a field HAT rotor experimental data. To verify the compatibility of the rotor design method and to analyze the properties of design factors, 3 rotor models were designed and experimented in a circular water channel. Three rotor models were designed according to different blade numbers and blade shapes. By changing flow velocity, rotor rpm, the rotor power and efficiency were measured and the properties of rotor were estimated. The results can be effectively applied to the design of current generation rotor.

• Transactions on Electrical and Electronic Materials
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• 제18권5호
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• pp.265-272
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• 2017

This paper presents the dynamic modeling, analysis, and control of an AC/DC/AC-assisted, self-excited induction generator connected to the grid. The dynamic model includes wind turbine models with pitch control, gear boxes, self-excited induction generators, excitation capacitance, inductive load models, controlled six-pulse rectifiers, and novel state-space models of a grid-connected inverter. The system has been simulated to verify its capabilities of buildup voltage, stator flux response, stator phase current, electromagnetic torque, and magnetizing inductance variation during both the dynamic and steady states with a variable-speed prime mover. The complete setup of the above dynamic models was simulated using MATLAB/SIMULINK.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.221-222
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• 2008

신재생에너지인 풍력발전이 우수한 실효성 및 경제성으로 인하여 보급이 지속적으로 증가되고 있다. 전력계통에서 발생하는 단락 및 지락고장은 고장 인접 풍력발전 설비 보호를 위해 풍력발전기를 계통으로부터 분리한다. 전력공급 신뢰도와 계통운영의 안정도를 향상시키기 위해서 풍력발기가 Fault-ride through 기능을 갖도록 하여 이를 보완한다. 본 논문에서 과도안정도 해석 프로그램을 이용하여 Fault-ride through 중요 변수인 전압저하 정도 및 고장지속 시간 등을 모의하여 실제 계통에 적용 가능한 모형을 제안한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.719-720
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• 2008

This paper deals with analytical approach for rotor loss prediction of permanent magnet synchronous generator(PMSG). The rotor losses of synchronous generator are induced by the magnets. Since stator of our model is skewed, slotting effect can be negligible for our PM wind turbine generator. In order to calculate eddy current, this paper derives analytical solutions by the magnetic vector potential. Finally this paper compared analytical result with eddy current density obtained from finite element(FE) calculations using phase current harmonics analysis.