• 풍력에너지저널
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• 제15권1호
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• pp.11-20
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• 2024

As the generation capacity of floating offshore wind turbines increases, the wind load applied to each turbine increases. Due to such a high wind load, the capacity of transport equipment (such as tugboats or cranes) required in the transportation and installation phases must be much larger than that of previous small-capacity wind power generation systems. However, for such an important wind load prediction method, the simple formula proposed by the classification society is generally used, and prediction through wind tunnel tests or Computational Fluid Dynamics (CFD) is rarely used, especially for a concept or initial design stages. In this study, the wind load of a 10 MW class floating offshore wind turbine was predicted by a simplified formula and compared with results of wind tunnel tests. In addition, the wind load coefficients at each stage of fabrication, transportation, and installation are presented so that it can be used during a concept or initial design stages for similar floating offshore wind turbines.

• 한국유체기계학회 논문집
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• 제15권4호
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• pp.50-54
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• 2012

Wind-power generation, which is recently drawing attention as one of renewable energies across the world, has been developed mainly by Europe. As the demand for the wind-power generation rose and the amount of wind-power generation increased, the studies on megawatt-class wind-power system have been active, and the use of composite with such properties as less weight, more strength, anti-corrosion and environment-friendliness has required gradually. In other word, wind turbine tower will be required to be lighter, more reliable and more consistent. Therefore it is necessary to lose weight of the wind turbine tower. This points squarely toward hybrid/composite tower production growing. It is important to note however that hybrid/composite tower production as it is today is flawed and that there are ways to improve greatly on the performance of these towers in manufacturing process and in their in-service performance. Through this, we have some detail on the current process and its advantage of cost and weight of towers.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.475-475
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• 2009

Recent alarming acceleration of global warming has made power generations using renewable energy to be in the middle of the spotlight. Korean government has also announced that it will make the related industry to be nation's one of main export items with high investments to low carbon green growth industry. To achieve this goal of exporting the renewable energy power generation system beyond domestic use, internationally acceptable rules should be applied and the three step processes of design, performance assessment and certification should follow international standards. Corresponding this international requests, IEC(International Electrotechnical Commission) is conducting the establishment of rules in TC88 for technical requirements of wind turbines. Design life-time of a wind turbine is required to be at least 20 years. In the meantime, the wind turbine will experience a lot of load cases such as extreme loads and fatigue loads which will include several typhoons per year and extreme gusts with 50 years recurrence period as well as endless turbulence flow. Therefore, IEC 61400-1 specifies design load cases to be considered in the wind turbine design and requires the wind turbine to withstand the load cases in various operational situations. It thus appears that the examination of contents and decisions discussed in the international standard committee will help people in the field of offshore wind energy and ocean energy converters.

• 한국산학기술학회논문지
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• 제14권5호
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• pp.2388-2392
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• 2013

풍력발전시스템은 기존의 발전시스템과 매우 다르다. 그러므로 전력계통에 풍력시스템을 연계하기 위해서는 동적특성에 대한 연구가 필요하다. 풍력발전기의 안정도해석은 전력계통의 운영에 있어서 중요 쟁점이다. 기존의 동기발전기만으로 구성된 전력계통의 위상각 안정도는 풍력발전기가 포함되면 그 결과가 달라진다. 즉, 풍력터빈에 연계된 발전기는 대부분 비동기인 유도발전기이기 때문이다. 위상각의 동기화 여부로 판별하는 위상각 안정도는 임계고장제거시간(CCT)을 계산하여 평가한다. 계통해석용 풍력터빈의 모델은 다양하여 그 해석에 어려움이 있으나 지금은 크게 4가지 타입으로 표준화가 되어있다. 본 논문에서는 PSS/E-32에서 제공하는 풍력터빈의 3번째 표준모델인 DFIG(Doubly-Fed induction Generator)모델을 이용하여 풍력단지가 연계된 전력계통의 CCT를 풍력단지의 위치와 용량을 고려하여 분석한다.

• 신재생에너지
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• 제10권2호
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• pp.19-28
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• 2014

Wind power generation of 5 MW wind turbine was predicted by using wind measurement data from HeMOSU-1 which is at south west coast of Korea. Time histories of turbulent wind was generated from 10-min mean wind speed and then they were used as input to Bladed to estimated electric power. Those estimated powers are used in both polynominal regression and neural network training. They were compared with each other for daily production and yearly production. Effect of mean wind speed and turbulence intensity were quantitatively analyzed and discussed. This technique further can be used to assess lifetime power of wind turbine.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1389-1391
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• 2003

The development of wind turbine power generation has grown during the past ten years. An important question, when installing wind turbines with the generator connected directly to the grid, is holt much the voltage quality will be affected by the uneven power production and by the connection of the wind turbine to the grid. This paper presents the voltage fluctuation of grid-connected WTG(wind turbine generators) by MATLAB/Simulink.

• 조명전기설비학회논문지
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• 제24권9호
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• pp.8-15
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• 2010

This paper analyzes the steady-state output characteristics of variable-speed wind turbine systems using doubly-fed induction generators(DFIG) compared with fixed-speed induction generator(FSIG) wind turbine systems. It also presents simulations of a grid-connected wind turbine generation system for dynamics analysis on MATLAB/Simulink and compares the responses between DFIG and FSIG wind turbine systems with respect to wind speed variation, impedance changes and X/R ratio changes of interconnecting circuits. Simulation results show the variation of generator's active output, terminal voltage and fault currents at the interconnecting point. Case studies demonstrate that DFIG wind turbine systems illustrate better performance to 3-phase fault than FSIG's.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권3호
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• pp.146-152
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• 2004

Cost effective simulation schemes for Wind Power Generation Systems (WPGS) considering wind turbine types, generators and load capacities have been strongly investigated by researchers. As an alternative, a true weather condition based simulation method using a real-time digital simulator (RTDS) is experimented in this paper for the online real-time simulation of the WPGS. A stand-alone WPGS is, especially, simulated using the Simulation method for WPGS using Real Weather conditions (SWRW) in this work. The characteristic equation of a wind turbine is implemented in the RTDS and a RTDS model component that can be used to represent any type of wind turbine in the simulations is also established. The actual data related to weather conditions are interfaced directly to the RTDS for the purpose of online real-time simulation of the stand-alone WPGS. The outcomes of the simulation demonstrate the effectiveness of the proposed simulation scheme. The results also signify that the cost effective verification of efficiency and stability for the WPGS is possible by the proposed real-time simulation method.

• 한국태양에너지학회 논문집
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• 제33권3호
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• pp.1-8
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• 2013

In order to identify positive or negative effect of seawall on wind turbine, a wind tunnel experiment has been conducted with a 1/100 scaled-down model of Goonsan wind farm which is located in West coast along seawall. Wind speedup due to the slope of seawall contributed to about 3% increment of area-averaged wind speed on rotor-plane of a wind turbine which is anticipated to augment wind power generation. From the turbulence measurement and flow visualization, it was confirmed that there would be no negative effect due to flow separation because its influence is confined below wind turbine blades' sweeping height.

• 한국산학기술학회논문지
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• 제14권6호
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• pp.2979-2984
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• 2013

본 논문은 도서지역에서 운용되고 있는 풍력-디젤 하이브리드 발전시스템의 풍속변화 등으로 인한 주파수변동 문제를 해결할 수 있는 플라이휘일 저장장치의 모델링 및 제어기 설계 방법을 제안하였다. 플라이휘일 저장장치는 효율측면에서 유리한 영구자석 동기기형 플라이휘일로 선정하여 모델링하였고, 주파수보상 제어기는 AC/DC/AC 양방향컨버터로 구성하되 동기기측 컨버터는 연계계통의 주파수변동에 대하여 충방전운전을 하도록 하고, 계통측 컨버터는 직류버스전압 일정제어를 통하여 출력을 하도록 설계하였다. 제안된 모델링 및 제어기 설계방법을 풍력-디젤 하이브리드 독립운전계통에 적용한 결과 풍속변화에 따른 주파수변동을 적정범위내로 유지할 수 있었다.