• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.591-603
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• 2022

This study was conducted to identify changes of insect compositions and diversity after construction of an onshore wind farm. We investigated insect fauna and compositions between a grassland deforested by the construction and a forest located at Yeongdeok and Yeongyang, Gyeongsangbuk-do, Korea. Insects were collected using a sweeping net and light trap. A total of 11 orders, 50 families, and 246 species, and 1,076 individuals were collected at study sites. By taxonomic group, Lepidoptera species were the most frequently found with 141 species, 417 individuals (38.8%), followed by Hymenoptera (20.6%), Hemiptera (16.2%), and Orthoptera (12.3%). There were also significant differences in insect species and community compositions between sites. Creating open-field deforested forests are beneficial for some insect groups such as Hymenoptera and Orthoptera. Our results suggest that deforesting by the construction of an onshore wind farm might affect the composition and diversity of insects. Results of this study provide basic data for research on onshore wind farms.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.249-250
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• 2012

해상 풍력 발전은 가장 유망한 재생 에너지원의 하나이며, 육상 풍력 발전보다 풍력이 강력하고 일정하여 장시간 고출력 발생이 가능하다. 또한 소음, 공간적 한계, 경관훼손 등 기존 육상 풍력 발전의 단점을 보완하고 초대형 단지조성이 가능한 장점이 있다. 초대형 해상풍력단지에는 일반적으로 MW급의 해상풍력발전기가 사용된다. 본 논문에서는 MW급의 해상 풍력발전기에 ANPC(Active Neutral-Point-Clamped) Multi-Level VSC(Voltage Source Converter)를 적용하여 Back-to-Back으로 구성한 시스템을 제안하고 계통연계형 풍력 발전 시스템을 모의한 시뮬레이션을 통하여 제안된 시스템의 성능을 검증한다.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1063-1069
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• 2011

This paper presents aerodynamic power outputs of wind turbine of 6 MW wind farm composed of 3 sets of 2 MW wind turbine according to the separation distance by using CFD. Layout design including offshore wind farm and onshore wind farm is key factor for the initial investment cost, annual energy production and maintenance cost. For each wind turbine rotor, not actuator disc model with momentum source but full 3-dimensional model is used for CFD and it has a great technical meaning. The results of this study can be applied to the offshore wind farm layout design effectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.47-52
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• 2021

Recently, the share of wind power in energy markets has sharply increased with the active development of renewable energy internationally. In particular, large-scale wind farms are being developed far from the coast to make use of abundant wind resources and to reduce noise pollution. In addition to the electromagnetic interference (EMI) caused by offshore wind farms to coastal or air surveillance radars, it is necessary to investigate the EMI on global maritime distress and safety system (GMDSS) communications between ship and coastal stations. For this purpose, this study investigates whether the transmitted field of MF/HF band from a ship would be subject to interference or attenuation below the threshold at a coastal receiver. First, using geographic information system digital maps and 3D CAD models of wind turbines, the area of interest is electromagnetically modeled with patch models. Although high frequency analysis methods like Physical Optics are appropriate to analyze wide areas compared to its wavelength, the high frequency analysis method is first verified with an accurate low frequency analysis method by simplifying the surrounding area and turbines. As a result, the received wave power is almost the same regardless of whether the wind farms are located between ships and coastal stations. From this result, although wind turbines are large structures, the size is only a few wavelengths, so it does not interfere with the electric field of MF/HF distress communications.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.36.1-36.1
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• 2011

풍력개발 기술이 발전함에 따라 풍력발전시스템이 점차 대용량화되는 추세이며, 경제성 있는 풍력단지 건설을 위해 점차 대단지화 되어가고 있는 실정이다. 이로 인해 풍력 발전단가(Cost of electricity, COE)도 개선되고 있다. 풍황이 양호한 풍력발전단지의 경우, 풍력발전 COE는 현재 50~60원/kWh 수준으로 타 신재생에너지원에 비해 경쟁력이 높고, 석탄 화력의 COE와 비교해 봐도 동등한 수준 혹은 더욱 경쟁력 있는 수준으로 감소하였다. 풍력발전단지 조성을 위해서는 시스템의 효율과 고효율, 저비용의 풍력발전시스템을 풍황이 좋은 지역에 설치할 때 낮은 COE를 가지는 경제성 있는 발전단지가 가능하다. 동급 용량 풍력발전시스템을 같은 지역에서 설치하여 에너지생산량을 증대시키기 위해서는 블레이드 지름의 증가시켜 유량을 증가시키거나 타워의 높이를 증가시켜 풍속을 증가시키는 방안이 있다. 이 경우 블레이드 길이와 타워 높이 증가에 의한 시스템 비용의 증가가 발생하는데, 에너지생산량 증가에 의한 수익비용과 시스템 비용 증가에 의한 자본비용은 서로 반비례로 영향을 미친다. 이를 위해 최소의 COE의 최대의 순현재가치(Net Present Value, NPV)를 갖는 목적함수로 두고 블레이드의 최적 길이와 타워의 최적 높이를 선정하였다.

• Electric Engineers Magazine
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• s.335
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• pp.11-13
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• 2010

우리나라는 좁은 국토 면적에 비하여 삼면이 바다로 둘러싸인 지형적인 장점을 가지고 있어 해상풍력발전단지를 조성하는데 유리한 조건을 가지고 있다. 또한 해상풍력은 장애물이 적기 때문에 바람의 난류(불규칙적인 흐름)와 풍속변화가 적어 육상풍력보다 해상풍력의 발전효율이 1.4배 높으며, 일반적으로 1.5~2배 정도 발전량이 높은 것으로 알려져 해상풍력 개발에 박차를 가하고 있다.

• Journal of Wind Energy
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• v.14 no.4
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• pp.57-67
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• 2023

This study aimed to investigate differences in turbulence intensity and turbine loads among onshore wind farms located in various types of terrain. To achieve this, simulations were conducted for two onshore wind farms with identical wind turbines and capacity but situated on complex and flat terrains. The simulations used meteorological data gathered over a 10-year period from automatic weather stations nearest to the wind farms. WindSim and WindPRO software tools were employed for wind field and load analysis, respectively. The simulation results revealed that wind farm A, situated on complex terrain, exhibited significantly higher effective turbulence intensity than wind farm B on flat terrain, as expected. Consequently, the load indices of several wind turbines exceeded 100 % in wind farm A, indicating that the turbines could not reach their design lifespan. From the simulation study, aimed at reducing both the effective turbulence intensity and turbine loads, it became evident that while increasing turbine spacing could decrease effective turbulence intensity to some extent, it couldn't completely resolve the issue due to the inherently high ambient turbulence intensity on complex terrain. The problem with wind turbine loads could only be completely resolved by using wind turbines with a turbine class of A+, corresponding to a reference turbulence intensity of 0.18.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.307-313
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• 2022

As the development of renewable energy expands internationally to cope with global warming and climate change, the share of wind power generation has been gradually increasing. Although wind farms can produce electric power for 24 h a day compared to solar power plants, Their interfere with the operation of nearby radars or communication equipment must be analyzed because large-scale wind power turbines are installed. This study analyzed whether a land radio station can receive sufficient signals when a ship sailing outside the offshore wind farm transmits distress signals on the VHF band. Based on the geographic information system digital map around the target area, wind turbine CAD model, and wind farm layout, the area of interest and wind farm were modeled to enable numerical analysis. Among the high frequency analysis techniques suitable for radio wave analysis in a wide area, a dedicated program applying physical optics (PO) and shooting and bouncing ray (SBR) techniques were used. Consequently, the land radio station could receive the electromagnetic field above the threshold of the VHF receiver when a ship outside the offshore wind farm transmitted a distress communication signal. When the line of sight between the ships and the land station are completely blocked, the strength of the received field decreases, but it is still above the threshold. Hence, although a wind farm is a huge complex, a land station can receive the electromagnetic field from the ship's VHF transmitter because the wave length of the VHF band is sufficiently long to have effects such as diffraction or reflection.

• Journal of Wind Energy
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• v.9 no.4
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• pp.32-39
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• 2018

In this study, the annual power production of a wind farm according to obstacles and wind data was predicted for the Garyeok-do wind farm in the Saemangeum area. The Saemangeum Garyeok-do wind farm was built in December 2014 by the Korea Rural Community Corporation. Currently, two 1.5 MW wind turbines manufactured by Hyundai Heavy Industries are installed and operated. Automatic weather station data from 2015 to 2017 was used as wind data to predict the annual power production of the wind farm for three consecutive years. For prediction, a commercial computational fluid dynamics tool known to be suitable for wind energy prediction in complex terrain was used. Predictions were made for three cases with or without considering obstacles and wind direction errors. The study found that by considering both obstacles and wind direction errors, prediction errors could be substantially reduced. The prediction errors were within 2.5 % or less for all three years.

• 기계와재료
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• v.23 no.3
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• pp.182-189
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• 2011

전 세계적으로 대체에너지 개발이 활발해지면서 국내에서도 풍력발전에 대한 관심이 높아지고 있다. 풍력발전을 신재생에너지 중에서 가장 상업화에 앞서 있으며 급속한 시장 확대와 산업의 발전을 가져온 분야이다. 1990년대에 개발되어 설치 운용되고 있는 약 20만대의 0.5 MW ~ 3 MW급 중대형 풍력발전기가 세계 여러 곳에서 상업발전을 하고 있으며, 국내에서는 제주도 행원풍력발전단지에 1998년부터 2003년 4월까지 총 15기(약 203억 원 투입)의 풍력 발전기가 도입되어 세워져 있으며, 1998년 8월에 600kW 풍력발전기 1 2호기의 상업운전을 최초로 시작하였다. 최근 풍력발전기의 설치 환경이 육상에서 해상으로 변하면서 5MW급 초대형 풍력발전기의 상용화가 시도되고 있으며 수요 또한 급증하고 있다. 본고에서는 전량 수입에 의존하고 있는 풍력발전기의 핵심 부품인 Yaw system(yaw bearing & drive)의 국내외 시장 동향과 초대형 요 베어링 및 고 강성 유성기어 감속기의 특성을 분석하였으며, 특히 전략적 국산화 개발필요성을 강조하였다.