• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.466-472
• /
• 2009

Offshore wind energy is gaining more and more attention during this decade. For the countries with coast sites, the water depth is significantly large. This causes attention to the floating wind turbine. Offshore wind turbines are designed and analyzed using comprehensive simulation codes that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity and controls of the wind turbine, along with the incident waves, sea current, hydrodynamics, and foundation dynamics of the support structures. In this work, a three-bladed 5MW upwind wind turbine installed on a floating spar buoy in 320m of water is studied by using of fully coupled aero-hydro-servo-elastic simulation tool. Specifications 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. Certain design load case is investigated.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.38.1-38.1
• /
• 2011

This study investigates the effects of Pierson-Moskowitz, Jonswap spectrum that are typical irregular wave spectrums for wind turbine system with jacket support structure. Also various offshore environmental parameters based on korean local condition were used in our study. The loads acting on the system was considered by referring to the Design Load Case from IEC guide line. And improved von Karman model was used as a turbulence model. As a result, various significant wave height and peak spectral period cause noticeable difference of extreme and fatigue loads prediction.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.262-267
• /
• 2008

The long-term wind data are reconstructed from the short-term meteorological data to design the 4 MW offshore wind park which will be constructed at Woljeong-ri, Jeju island, Korea. Using two MCP (Measure-Correlate-Predict) models, the relative deviation of wind speed and direction from two neighboring reference weather stations can be regressed at each azimuth sector. The validation of the present method is checked about linear and matrix MCP models for the sets of measured data, and the characteristic wind turbulence is estimated from the ninety-percent percentile of standard deviation in the probability distribution. Using the Gumbel's model, the extreme wind speed of fifty-year return period is predicted by the reconstructed long-term data. The predicted results of this analysis concerning turbulence intensity and extreme wind speed are used for the calculation of fatigue life and extreme load in the design procedure of wind turbine structures at offshore wind farms.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.2
• /
• pp.60-65
• /
• 2014

A meteorological(met) tower is the first structure installed during the planning stages of offshore wind farm. The purpose of this paper is to design the met tower with tripod bucket type support structure and to install the sensors. The support structure consist of a central steel shaft connected to three cylindrical steel suction buckets which is more cheaper than monopile or jacket type. And the remote wind condition sensors and marine monitoring equipment, including adcp, pressure type tide gauge, wave height sensors, and scour sensors, remote power supply are installed. The manufactured met tower constructed on sea area which is in front of Gasa island. All of functions of met tower showed normal operation conditions and the wind data got by remote data collection system successfully.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.8
• /
• pp.1020-1027
• /
• 2007

As a national enterprise has been expanded over and over, the worldwide energy consumption has been growing necessarily. Moreover, as recently energy spendings are on the increase in countries such as BRICs, it has resulted that a rise in the price of both oil and mineral resources and instability between supply and demand become serious issue in the world resources market. The recent high price of oil and mineral resources have a deep influence on economy and threaten energy security and even national prosperity of Korea. In addition to these, exhaustion of fossil fuels and the enhanced greenhouse effect which results from gases emitted as a result of fossil fuels has been in serious questions which occur a great deal of effort to secure clean energy resources all around the world. As it is considerably possible for Korea that the Kyoto protocol may come into effect on and after 2013, it is essential to require the technological development to promote energy efficiency as well as to develope safe and renewable energy resources. The wind energy technology which converts kinetic energy into electrical energy has been in the focus of the world's attention. In this study, two-dimensional numerical analyses were conducted to observe subsidence aspects of the sea bottom on differently applied loads and various ground conditions.

• Journal of the Korean Geosynthetics Society
• /
• v.14 no.4
• /
• pp.129-137
• /
• 2015

Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. One of the most obvious applications of the pressuremeter test is the solution of the problem of laterally loaded piles. A hyperbolic non-linear p-y criterion for rock is developed in this study that can be used in LPILE program, to predict the deflection, moment, and shear reponses of a shaft under the applied lateral loads. Finally, a comparison between the predicted and measured response at two different sites is shown to give an idea of the accuracy of the IFP method.

• Journal of the Korean Geosynthetics Society
• /
• v.15 no.1
• /
• pp.1-10
• /
• 2016

Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. In this study, field lateral load test of the pile for analyzing lateral behavior of the offshore wind turbine which is embedded in basalt. After calculating the subgrade resistance and the horizontal deflection from the measured strain to derive p-y curve from the lateral load test results, the subgrade resistance amplifies the error in the process of differentiation and the error of piecewise polynomial curve fitting is the smallest. In order to calculate the horizontal deflection from the measured strain, the six-order polynomial was used.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.1
• /
• pp.77-84
• /
• 2022

A submarine power cable is a transmission cable for carrying electric power below the surface of the water. Recently, submarine cables transfer power from offshore renewable energy schemes to shore, e.g. wind, wave and tidal systems, and these cables are either buried in the seabed or lie on the ocean floor, depending on their location. Since these power cables are used in the extreme environments, they are made to withstand in harsh conditions and temperatures, and strong currents. However, undersea conditions are severe enough to cause all sorts of damage to offshore cables, these conditions result in cable faults that disrupt power transmission. In this paper, we explore the design criteria for such cables and the procedures and challenges of installation, and cable transfer splicing system. The specification of submarine cable designed with 3 circuits of 154kV which is composed of the existing single circuit and new double circuits, and power capacity of 100MVA per cable line. The determination of new submarine cable burial depth and cable arrangement method with both existing and new cables are studied. We have calculated the permission values of cable power capacity for underground route, the values show the over 100MW per cable line.

• Journal of Wind Energy
• /
• v.15 no.1
• /
• pp.5-10
• /
• 2024

Offshore wind power generation has significant advantages, including enhanced energy security and job creation. However, despite these benefits, South Korea has not fully utilized its potential in this sector. In contrast, offshore wind power industry development in Europe has been driven by government leadership. Drawing from this experience, South Korea also needs to relax regulations, strengthen necessary infrastructure, and enhance financial support systems to activate the offshore wind power industry. For this, sustained government leadership is absolutely essential. Without addressing the capacity issues in the power grid, we cannot expect offshore wind power generation to succeed. To address grid issues, we propose the enactment of a special law called the "Special Act on Grid Expansion." Considering KEPCO's financial situation, private investment should be encouraged for grid construction. The role of developers is crucial for the successful development and operation of offshore wind power. They manage risks throughout various stages, from site acquisition to construction and operation, which have a significant impact on the success or failure of projects. Since domestic developers currently lack experience in offshore wind power, a cooperative strategy that leverages the experience and technology of advanced countries is necessary. Energy issues should be recognized as important tasks beyond mere political ideologies, as they are crucial for the survival of the nation and its development. It is essential to form a public consensus and implement ways for residents to coexist with offshore wind power, along with the conservation of marine ecosystems and effective communication with stakeholders. Expansion of the offshore wind power industry requires support in various areas, including financial and tax incentives, technology research investment, and workforce development. In particular, achieving carbon neutrality by 2050 necessitates the activation of offshore wind power alongside efforts by major corporations to transition to renewable energy. South Korea, surrounded by the sea, holds significant offshore wind power potential, and it is our responsibility to harness it as a sustainable energy source for future generations. To activate the offshore wind power market, we need to provide financial and tax support, develop infrastructure and research, and foster a skilled workforce. As major corporations transition to renewable energy to achieve carbon neutrality by 2050, offshore wind power must play a significant role. It is our responsibility to fully utilize South Korea's potential and make offshore wind power a new driver of growth.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.3
• /
• pp.387-396
• /
• 2023

The representative equipments currently used for weather observations are meteorological masters and wind lidars. According to international regulations, meteorological masters can be used for standalone measurements, but in case of wind lidars, it is mandatory to install a meteorological master that matches the height of the bottom of the wind turbine blade or a 40m meteorological masters and correct the measurement data. Turbulence flow occurs frequently at altitudes below 100m due to its nature, and wind lidars are more susceptible to the effects of turbulence than meteorological masters. However, while the turbulence intensity for meteorological masters is specified by international regulations, there is no separated specification for wind lidars. This study collected data measured under the same conditions using both meteorological masters and wind LiDARs, analyzed the uncertainties and turbulence intensity ratio. The analysis of the data showed that there were partial sections where the proportion of turbulent flow intensity exceeded 3%. Therefore, it is suggested to include a specification for the turbulence intensity error rate for wind LiDARs in the international regulations.