• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.480-485
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• 2009

Offshore wind energy is gaining more attention. Ensuring proper design of offshore wind turbines and wind farms require knowledge of the external conditions in which the turbines and associated facilities are to operate. In this work, a three-bladed 5MW upwind wind turbine, which is supported by the monopile foundation, is studied by use of fully coupled aero-hydro-servo-elastic commercial simulation tool, 'GH-Bladed'$^{(R)}$. Specification of the structures are chosen from the OC3 (Offshore Code Comparison Collaboration) under "IEA Wind Annex XXIII-subtask2". The primary external conditions due to wind and waves are simulated. Design Load case 5.2 is investigated in this work. The steady state power curve and power production loads are evaluated. Comparison between different codes is made.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.366-369
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• 2007

This paper presents the general results of the conceptual design of a 3MW class offshore wind turbine named WinDS 3000 under development. In WinDS 3000, an integrated drive train design, three stage gearbox and permanent magnet generator (PMG) with fully rated converters have been introduced. A pitch regulated variable speed power control with individual pitch control has been adopted to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. Through the introduction of WinDS 3000, it is expected that helpful to understanding of the development status of 3MW offshore wind turbine.

• New & Renewable Energy
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• v.6 no.3
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• pp.39-46
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• 2010

With growing of wind turbine industry, offshore wind energy is getting more attention in recent years. Among all the components of offshore wind turbines, the foundation of the offshore wind turbine plays a key role in stability of whole system. In this work, the 5 MW NREL reference wind turbine with rated speed of 11.4 m/s is used for load calculation. Wind and wave loads are calculated using GH-Bladed (Garard Hassan) and FAST (NREL). Additionally, FE simulation is carried out to investigate the wave effect on the support structure. Meanwhile, this work is to simulate systemic and optimized load cases for the foundation analysis of wind turbine system.

• New & Renewable Energy
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• v.6 no.3
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• pp.47-54
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• 2010

Foundation plays an important role in the offshore wind turbine system. Different from conventional foundations, the suction caisson is proven to be economical and reliable. In this work, three-dimensional finite element method is used to check the suitability of suction caisson foundation. NREL 5MW wind turbine is chosen as a baseline model in our simulation. The maximum overturning moment and vertical load at the mudline are calculated using FAST and Bladed. Meanwhile the soil-structure interaction response from our simulation is also compared with the experiment data from Oxford university. The design parameter such as caisson length, diameter of skirt and spacing of multipod are investigated. Accordingly based on these parameters suggestions are given to use suction caisson foundations more efficiently.

• Journal of the Korean Solar Energy Society
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• v.30 no.5
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• pp.44-55
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• 2010

The proposed offshore wind farm projects, i.e., Mooudo offshore, Yeonggwang-Gochang offshore, Saemangeum offshore, Imjado offshore and Gadeokdo-Dadeapo offshore, were compared and analyzed using the Korea National Wind Mapand Wind Farm Suitability Assessment System developed by the Korea Institute of Energy Research. The suitability of the proposed areas was comprehensively assessed using geographic, economic constraints, wave condition and wind resource factors, but the focus of this paper was on the geographic constraints and wave conditions. Imjado had several geographical constraints, despite having a good wind power density, while Saemangeum had a relatively low wave height, shallow water depth, close substation and slow tidal current. It is anticipating that the present comparison and analysis could be used as reference guidelines when selecting and preparing the design of large-scale offshore wind farm in the near future.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.39.1-39.1
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• 2011

Due to less turbulence and no land limitation, offshore wind energy gets more attention than onshore. Jacket structure is regarded as a suitable solution for the water depth ranging from 30 to 80 meters. In general, joint stress concentration of jacket support structures affects their fatigue life. Nowadays, most jacket structures for offshore wind turbines have tubular X-joint between legs. In this paper, a study on X-joint stress concentration of offshore wind turbine jacket structure is performed by using 50m water depth model. Stress of X-joint on offshore environmental conditions are discussed.

• Journal of the Korean Solar Energy Society
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• v.23 no.2
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• pp.35-41
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• 2003

In order to investigate the offshore wind resources around Korean peninsula, the "QuikSCAT Level 3" data by ADEOS II satellite was analyzed from Jan 1 2000 to Jan 18 2003. The "SeaWinds" on the satellite is a specialize4 device for microwave scatterometery that measures near-surface wind speed and direction under all weather and cloud conditions. Wind speed are extrapolated from 10m to 60m with the exponent of 1/10 in the power law model. It has been found that the High wind energy potentials are prevailing in the South sea and Southeastern end of Korean peninsula.

• New & Renewable Energy
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• v.18 no.4
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• pp.22-37
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• 2022

Large-scale offshore wind power is emerging as a viable solution to achieve carbon neutrality and solve climate change. As power generation complexes require ample space for construction, they create conflicts with residents near the construction site. To resolve the issue with residents, Korea, along with other countries, has developed policies that focus on influencing public perception. However, as the contents of such policies changed several times in a short period in Korea, they were differently applied depending on the timing of the project. This study examines how Korean offshore wind power site development policies, particularly the ones focusing on swaying public perception, were applied differently by regions.

• Journal of Wind Energy
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• v.14 no.3
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• pp.91-99
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• 2023

In research conducted on a southwestern Korean offshore meteorological tower, acceleration datasets were gathered over half a year with time-history sensors. To enhance data credibility, a parallel measurement system was used for verification. A model of the tower was configured using beam elements, and with modifications accounting for added stiffness from auxiliary structures. Ground interactions were considered as calibrated springs based on soil layer properties. The tower's dynamic attributes and mass sensitivity were discerned using eigenvalue analysis. The structural natural frequency was consistent, with variations primarily due to new equipment adding approximately 1400 kgs. With free vibration damping assumptions, a damping ratio of roughly 1 % was derived.

• Journal of Navigation and Port Research
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• v.38 no.2
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• pp.105-110
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• 2014

Korean government sets up a goal that jumps up to the third ranked powerful nation of offshore wind in the world until 2020 and announced "The plan for 2.5-gigawatt wind farm off the south-west coast by 2019". Such above, according to green energy policy, offshore wind farms(OWF) will be increased continuously. The development of OWF should be taken account of wind volume as well as marine traffic environment. Specially aids to navigation of OWF play a significant role in preventing collision between vessels navigating near waters and structures. For purpose of distinguishing OWF, IALA recommendations define installation of lights on SPS and IPS. However, there is no mention of light character that plays important role in identification of lights as marking offshore wind farm. Also the research on selection of proper light character has been insufficient state. Therefore in this paper, we analyzed internal and external regulations concerned marking with light on SPS and IPS in OWF. And suggested patterns and rhythms of light having not only easily recognized feature but also no confusion with other light of aids to navigation. The proposed light characters were verified by simulation, and the results were analysed that synchronism flickering of "Fl Y(4) 12s(SPS)" and "Fl Y 6s(IPS)" would be useful in combination of both lights.