• Journal of Wind Energy
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• v.15 no.1
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• pp.30-42
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• 2024

This paper examines the design feasibility of cage aquaculture coexistent with an offshore wind farm in the southwestern sea of South Korea. Among the many types of fish farms, 2 × 3 cage aquaculture was selected for the investigation and the initial design including mooring lines, bridles, etc. was drawn with iterative numerical simulations using Orcaflex. Experimental campaigns were conducted to validate the numerical results, and they were found to be in good agreement with the experiments. Using a validated numerical model, the tension of mooring lines and the deformed volumes of the facility were examined under given operating and survival conditions. The validated model will be further used to investigate various aspects of the cage farm design for design optimization.

• Journal of Wind Energy
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• v.13 no.3
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• pp.79-87
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• 2022

A stabbing system is an underwater jointing structure for positioning the jacket substructure for offshore wind power on top of a pile foundation that is already installed in the seabed. In this paper, the structural safety of the stabbing system currently being developed in South Korea was evaluated through finite element analysis. For this study, conformity of the finite element modeling technique for a gripper (hydraulic cylinder) was reviewed, and the structural safety of the stabbing system was evaluated based on the stress safety factor under three design load combinations (combinations of vertical, shear, and moment loads). From the analysis, it was verified that the pile foundation and the stabbing system mounted on top of it are structurally safe according to the stress safety factor, and there will be no interference between major structural components (i.e., guide cone and pile foundation) due to rotation of the guide cone at the end of the jacket leg.

• Journal of Wind Energy
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• v.13 no.2
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• pp.5-12
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• 2022

Operations and maintenance (O&M) in offshore wind farms accounts for a substantial portion of the life cycle cost due to harsh weather conditions and vessel dispatching. In this regard, it is crucial to expedite O&M technologies in South Korea, which is in the early stage of harnessing wind resources from the ocean. This contribution investigates an O&M planning and scheduling model for floating offshore wind farms with a literature review and use case study. We introduce the development of a long- and short-term maintenance planning framework as part of an integrated O&M platform. This contains a single vessel and fleets routing composition along with technicians and a maintenance job list based on numerical algorithms. Additionally, the routing search presents the basis of decision support for economic trade-offs regarding smooth operation corresponding to ever-changing wind farm situations. The maintenance planning simulator will ultimately contribute to support yearly and day-to-day power-related decisions in a cost-effective manner.

• Journal of Wind Energy
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• v.15 no.3
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• pp.5-20
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• 2024

This study examines how ecological impacts are addressed in the siting processes of European countries that are international leaders in offshore wind energy, and draws implications for Korea. The United Kingdom, Germany, the Netherlands, and Denmark are the countries with the most offshore wind installations after China. These European countries conduct strategic environmental assessments (SEAs) and appropriate assessments (AAs) at both the overall site planning stage and the individual site decision stage to evaluate ecological impacts from offshore wind power. In the UK, the SEA and AA for offshore wind are conducted separately at different stages of the siting process. Germany has three siting stages, and the Netherlands and Denmark have two siting stages, each of which includes both an SEA and an AA. Compared to the SEA, which assesses overall ecological impacts, the AA is limited to impacts on Natura 2000 sites, a network of protected areas for species and habitats. The ecological impacts of offshore wind are examined for birds, bats, marine mammals, fish, and benthic organisms.

• Journal of Wind Energy
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• v.15 no.3
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• pp.30-37
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• 2024

Since the Paris Agreement, countries around the world have been planning to introduce RE100, CF100 and the Carbon Border Adjustment Mechanism to achieve carbon neutrality. In these policies, advanced and renewable energy sources such as wind power, solar power and geothermal heat are recognized as core power resources to deal with climate change. The contribution of this study is that the wind power industry was added to the 33 major categories in the 2015 regional input-output table, published by the Bank of Korea, expanding the total to 34 sectors. As a result, the spillover effects of the 2.4 GW offshore wind power project are as follows. First, the domestic direct and indirect production effect amounts to 25.0 trillion won. Among these, Jeonbuk's production effect reaches 6.3 trillion won. Second, the domestic direct and indirect value-added effect is 9.3 trillion won, of which the Jeonbuk region's value-added effect is 2.4 trillion won. Third, the domestic direct and indirect employment effect is 450,643 people, of which the Jeonbuk region's employment effect is 125,085 people. The limitation of regional input-output analysis is that an increase in input due to inflation can lead to an increase in output, which may lead to a discrepancy from economic reality.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.3
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• pp.205-210
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• 2008

In recent years, the crisis of energy is growing seriously and also the contamination of ecology has been reverberated as international problem. The social concern about energy crisis has been growing for the last several years and also the interest in new and renewable energy has been increased. The probability of wind power resource over Saemangeum is reviewed with the data of Gunsan weather station. Through this study, it is cleared that the Saemangeum area has fluent wind power source to design the wind farm in Korea. According to calculation results, it is possible to predict the wind velocity density around the Saemangeum area using the shape factor as a parameter.

• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.155-163
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• 2024

As the demand for reducing carbon emissions increases, efforts to reduce the usage of fossil fuels and research on renewable energy are also increasing. Among the various renewable energy harvesting techniques, the floating offshore wind turbine has several advantages. Compared to other technologies, it has fewer installation limitations due to interference with human activity. Additionally, a large wind turbine farm can be constructed in the open ocean. Therefore, it is important to conduct motion analysis of floating offshore wind turbines in waves during the initial stage of conceptual design. In this study, a frequency motion analysis was conducted on a semi-submersible type floating offshore wind turbine. The analysis focused on the effects of varying trim on the motion characteristics. Specifically, motion response analysis was performed on heave, roll, and pitch. Natural period analysis confirmed that changing the trim angle did not significantly affect the heave and pitch motions, but it did have a regular impact on the roll motion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1121-1130
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• 2009

In order to investigate the offshore wind resources, the measured data from the QuikSCAT satellite was analyzed from Jan 2000 to Dec 2008. QuikSCAT satellite is a specialized device for a microwave scatterometer that measures near-surface wind speed and direction under all weather and cloud conditions. Wind speed measured at 10 m above from the sea surface was extrapolated to the hub height by using the power law model. It has been found that the high wind energy prevailing in the south sea and the east sea of the Korean peninsula. From the limitation of seawater depth for piling the tower and archipelagic environment around the south sea, the west and the south-west sea are favorable to construct the large scale offshore wind farm, but it needs efficient blade considering relatively low wind speed. Wind map and monthly variation of wind speed and wind rose using wind energy density were investigated at the specified positions.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.45-56
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• 2013

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 paper, the settlement and stress distribution is predicted by numerical analysis when the mono-pile base are constructed on various soft layer between stratified structure. To determine the settlement of the pile foundation supported on stratified rock layer, the geological investigation at the 3 regiions and the results of laboratory experiments of the stratified rock layer is required.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.65-76
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• 2024

With the recent activation of the offshore wind power industry, there has been a development of power plants with a scale exceeding 400MW, comparable to traditional thermal power plants. Renewable energy, characterized by intermittency depending on the energy source, is a prominent feature of modern renewable power generation facilities, which are structured based on controllable inverter technology. As the integration of renewable energy sources into the grid expands, the grid codes for power system connection are progressively becoming more defined, leading to active discussions and evaluations in this area. In this paper, we propose a method for selecting optimal reactive power compensation capacity when multiple offshore wind farms are integrated and connected through a shared interconnection facility to comply with grid codes. Based on the requirements of the grid code, we analyze the reactive power compensation and excessive stability of the 400MW wind power generation site under development in the southwest sea of Jeonbuk. This analysis involves constructing a generation site database using PSS/E (Power System Simulation for Engineering), incorporating turbine layouts and cable data. The study calculates reactive power due to charging current in internal and external network cables and determines the reactive power compensation capacity at the interconnection point. Additionally, static and dynamic stability assessments are conducted by integrating with the power system database.