• 산업기술연구
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• 제22권A호
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• pp.49-57
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• 2002

The accurate wind speed information at the hub height of a wind turbine is very essential to the exact estimation of the wind turbine power performance testing. Several methods on the site calibration, which is a technique to estimate the wind speed at the wind turbine's hub height based on the measured wind data using a reference meteorological mast, are introduced. A site calibration result and the wind resource assessment for the Taekwanryung test site are presented using a one-month wind data from a reference meteorological mast and a temporal mast installed at the site of wind turbine. From this analysis, it turns out that the current location of the reference meteorological mast is wrongly determined, and the self-developed codes for the site calibration are working properly. Besides, an analysis on the uncertainty allocation for the wind speed correction using site calibration is performed.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권4호
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• pp.625-634
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• 2013

Energy is a direct restriction to the working life of an underwater mooring platform (UMP). In this paper, a vertical axis water turbine (VAWT) is designed to supply energy for UMPs. The VAWT has several controlled blades, which can be opened or closed by inside plunger pumps. Two-dimensional transient numerical studies are presented to determine the operating performance and power output of the turbine under low ocean current velocity. A standard k-${\varepsilon}$ turbulence model is used to perform the transient simulations. The influence of structural parameters, including foil section profile, foil chord length and rotor diameter, on the turbine performance are investigated over a range of tip-speed-ratios (TSRs). It was found that turbine with three unit length NACA0015 foils generated a maximum averaged coefficient of power, 0.1, at TSR = 2.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.104-108
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• 2004

Micro turbine is an electric power generating system using a gas turbine whose rated power is under 300kW, and it is featured as a small, efficient. maintenance free and environment-friendly system. Air foil bearing has several advantages over conventional bearings for micro turbine because it is oilless and non-contact. Recently, air foil bearings for high temperature over $500^{\circ}C$ has been developed for the application of 65kW micro turbine system. In this paper, the development and current status are summarized in detail.

• Wind and Structures
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• 제7권5호
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• pp.305-316
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• 2004

In this study, a wind tunnel, that has been developed for experiments of wind turbine rotor blades, has been considered. The deviations of the measurements have been examined after this wind tunnel had been introduced and the measurements on it had been explained. Two different wind turbine rotor blades miniatures have been used for getting better results from the experiments. The accuracy of measurements have been experimented three times repetitively and examined statistically. As a result, wind speed values which this type of wind tunnel and wind turbine rotors need for starting, wind speed in the tunnel, temperature and moisture values, the number of rotor's revolution, and the voltage that is produced in 102 ${\Omega}$ resistance and current values have been determined to be fixed by measurements used. This type of wind tunnel and wind turbine rotor' performance difference and the difference of revolution figures have been determined to be fixed by measurements used.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.236.1-236.1
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• 2010

Due to global warming, the need to secure an alternative resource has become more important nationally. Due to the high tidal range of up to 9.7m on the west coast of Korea, numerous tidal current projects are being planned and constructed. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system, and its performance is determined by various design variables. In this paper, 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, 3D CFD model was designed and analysed by ANSYS CFX. The analysis results and findings are summarized in the paper.

• 한국정밀공학회지
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• 제33권2호
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• pp.157-163
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• 2016

The empirical evaluation of grid-connected tidal current generation system is presented in this paper. The Ul-dol-mok in Jin-do has been estimated to have tidal power of 1GW. In order to experiment, HAT (Horizontal Axis Turbine) 3-blade and 20kW grid-connected tidal current generation system was established at Ul-dol-mok in Jin-do. To generate power of generator, the speed reference of the PMSG is generated from the Cp curve and TSR (Tip Speed Ratio) of the designed turbine. The control of the converter connected to the grid is controlled to regulate unity power factor. The result showed that the turbine efficiency and system efficiency is 37 % and 31 %. This was achieved that target rate is 30 %, 20 %, respectively.

• Journal of Advanced Research in Ocean Engineering
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• 제1권3호
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• pp.176-185
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• 2015

Recently, focus has been placed on ocean energy resources because environmental concerns regarding the exploitation of hydrocarbons are increasing. Tidal current power, one of the ocean energy resources, has great potential worldwide due to its high energy density. The flow velocity is the most crucial factor for the power estimation of TCP(Tidal Current Power) system since the kinetic energy of the flow is proportional to the cube of the flow speed. So sufficient inflow speed to generate electricity from the tidal current power is necessary. A duct system can accelerate the flow velocity, which could expand the applicable area of TCP systems to relatively lower velocity sites. The shapes of the inlet and outlet could affect the flow rate inside the duct. To investigate the performance of the duct, various ducts were preliminary designed considering the entire system that is single-point moored TCP system and a series of simulations were carried out using ANSYS-CFX v13.0 CFD software. This study introduces a ducted turbine system that can be moored to a seabed. A performance estimation and comparison of results with conventional tidal converters were summarized in this paper.

• 전력전자학회논문지
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• 제10권4호
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• pp.397-402
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• 2005

유도기의 고정자를 직접 전력 계통에 연결하는 유도형 풍력발전기의 계통 연계시 과도 상태 돌입 전류의 크기를 줄이기 위한 새로운 소프트 스타터(Soft Starter) 제어 알고리즘을 제안하였다. 현재 국내에 가장 많이 설치되어 있는 정속 운전형 풍력발전시스템의 기본 구성을 살펴보고 특히 소프트 스타터의 계통 연계 알고리즘에 따라 발전 개시 순간 과도 상태 전류의 크기가 크게 달라짐을 확인하였다. 이를 위해 600kw급 유도 발전기를 포함한 정속형 풍력발전 시스템의 시뮬레이션 모델을 개발하였고 실험실 환경에서 제안된 알고리즘을 시험하기 위한 3.7kW급 모의실험장치를 제작하였으며, 소프트 스타터의 제어 알고리즘 개선에 의해 돌입전류의 크기가 약 20$\%$ 감소됨을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.160.2-160.2
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• 2011

바다를 가로막는 방벽이나 방조제의 배수갑문 또는 조력발전소의 수문과 같이 인공 해양구조물을 통하여 흐르는 고속 해류를 이용하여 발전하는 해류발전 방식에 있어서, 고속 해류에 적합한 수차터빈과 발전기의 특성을 알아보았다. 조석간만의 차가 큰 지역에 설치되는 인공 해양구조물을 지나는 해류는 인공 해양구조물 전후에 발생하는 해수의 위치에너지 차이가 운동에너지로 바뀌면서 조석간만의 자연현상에 의해 발생되는 조류의 속도보다 훨씬 더 빠르게 흐른다. 이론적으로 우리나라의 서해안의 조석간만의 범위 3~8m로부터 7.5~12m/s 정도의 고속 해류가 가능하다. 이러한 경우에 적합한 해류발전기는 수차터빈 날개지름의 크기가 5m에서부터 12m 이하이면서, 증속기어박스와 발전기, 유압시스템 및 냉각시스템 그리고 전력변환장치를 포함하는 발전시설들을 해수면 위에 설치하는 것이 바람직하다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.454-457
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• 2007

This study suggests a modeling of grid-connected wind turbine generation system that has induction generator, and aims to perform simulations for outputs by the variation of actual wind speed and for fault current of wind generation system by the transformer winding connection. This study is implemented by MARTLB & SIMULINK. The simulation shall be performed by assuming single line to ground fault generated in the system Generator power, rotor speed, terminal voltage, system voltage, and fault current shall be observed following the performance of simulation. The fault current change will be dealt through the simulation results for fault current of wind generation system following the grid-connected transformer winding connection and the simulation result by the transformer neutral ground method.