• 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 the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.658-665
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• 2019

Among the renewable energy resources, wind power is growing rapidly in terms of technological development and market share. Recently, onshore wind farm have been affected by limitations of terrestrial space and environmental problems. Consequently, installation sites have been moved to the sea, and the development of floating offshore wind farms that are installed at deep waters with more abundant wind conditions is actively underway. In the context of maritime traffic, the optimal site of offshore wind farms is required to minimize the interference between ships and wind turbines and to reduce the probability of accidents. In this study, genetic algorithm based AIS(Automatic Indentification System) data composed of genes and chromosomes has been used. The optimal site of floating offshore wind farm was selected by using 80 genes and by evaluating the fitness of genetic algorithm. Further, the final site was selected by aggregating the seasonal optimal site. During analysis, 11 optimal site were found, and it was verified that the final site selected usng the genetic algorithm was viable from the perspective of maritime traffic.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.633-644
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• 2013

This study evaluates wind farm efficiency at Haengwon in Jeju Island. The actual energy production at Haengwon wind farm is compared with the estimated energy production based on Korean wind map which is developed at the National Institute of Meteorological Research/KMA. The validation of wind map at Gujwa located near the Haengwon wind farm shows that the wind speed is overestimated. The diurnal variation of wind speed shows a maximum value in the afternoon due to the effect of sea-land breeze. The ratio of the actual energy production at Haengwon wind farm and the estimated energy production based on the Korean wind map is 24.8%, while the distribution of energy frequency is similar each other. The difference of energy production is caused by mechanical error of the turbine and the overestimation of the simulated wind map. This study will contribute to the repowering of turbines for improving the efficiency of wind farm in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.186-192
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• 2014

In this paper, we analysed vessel traffic volume and patterns of traffic flow for ships using areas where included wind farm site and adjacent waters of Daejeong Offshore Wind Farm, and estimated traffic volume by classified navigational routes according to suggestion of rational routeing measures on the basis of classified patterns after installation of offshore wind facilities. Also, we assessed vessel traffic safety for each designed routeing measures on the basis of estimated traffic volume and proposed requisite countermeasures for the safe navigation of ships. With a result of analysing patterns of traffic flow, the current traffic flow was classified by 8 patterns and the annual traffic volume was predicted to 8,975 ships. On the basis of these, expected the vessel traffic volume according to designed four routeing mesaures after installation of wind farm. As result of assessing vessel traffic safety by using powered-vessel collision model of SSPA on the basis of the estimated traffic volume, the value of collision probability was less than safe criteria $10^{-4}$. Thereby we made sure usability of the designed routeing measures for the safe navigation of ships.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.3
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• pp.57-66
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• 2023

In order to understand the economic feasibility of an offshore wind farm, this paper analyzed the differences in LCOE (levelized cost of energy) according to the support type and construction method of the substructure in terms of LCOE and sensitivity analysis was conducted according to the main components of LCOE. As for the site to be studied, the Southwest Offshore Wind Farm was selected, and the capital expenditures were calculated according to the size of the offshore wind farm and the installation unit. As a result of the sensitivity analysis, major components showed high sensitivity to availability, turbine related cost, weighted average cost of capital and balance of system related cost. Moreover, the post-piling jacket method, which was representatively applied to the substructure of the offshore wind farm in Korea, was selected as a basic plan to calculate the capital expenditures, and then the capital expenditures of the pre-piling jacket method and the tripod method were calculated and compared. As a result of analyzing the LCOE, it was confirmed that the pre-piling jacket method of the supporting structure lowers the LCOE and improves economic feasibility as the installation number of turbines increases.

• Journal of IKEEE
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• v.24 no.3
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• pp.691-698
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• 2020

The installation cost or the magnitude of the fault current varies depending on the grid connection method of the offshore wind farm. Therefore, there is a need for an efficient power grid connection method considering the capacity and location of the complex. In particular, most power cables in offshore wind farms use 3-core considering cost and efficiency. In the event of a failure such as a short circuit, the entire cable must be replaced, which can lead to significant losses in terms of cost, considering repair costs and turbine downtime. Therefore, in this paper, a radial, ring, and molding method is introduced into a 100 MW wind farm to be installed at Jeju offshore, and a three-phase short circuit failure is performed using a PSCAD/EMTDC program to perform computer analysis. I would like to propose a suitable power grid connection method.

• JOURNAL OF ELECTRICAL WORLD
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• s.418
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• pp.64-71
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• 2011

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.547-554
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• 2018

Wind energy is widely recognized as one of the cheapest forms of clean and renewable energy. In fact, in several countries, wind energy has achieved cost parity with fossil fuel-based sources of electricity generation for new electricity generation plants. Offshore wind energy development promises to be a significant domestic renewable energy source for the target of korea government 3020 plan. A pivotal activity during the development phase of a wind project is wind resource assessment. Several approaches can be categorized as three basic scales or stages of wind resource assessment: preliminary area identification, area wind resource evaluation, and micrositing. This study is to estimate the wind power capacity of chonnam province offshore area using three basic stages based on the six meteorological mast data. WindPRO was used, one of a well-known wind energy prediction programs and based on more than 25 years of experiences in development of software tools for wind energy project development. The design results of offshore wind power generation capacity is calculated as total 2.52GW with six wind farms in chonnam offshore area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.2
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• pp.130-139
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• 2013

In recent, the communication networks of wind power farm are becoming crucial technologies for monitoring and controlling the large-scale offshore wind power farm. In this paper, EPON based communication network architectures are proposed in order to combat the problems of conventional Ethernet based communication network such as delay, data processing overhead and the fairness of data transmission among turbines in offshore wind power farm. The proposed architecture constructs the point to multi-point network by using OLT and ONUs installed in central control center and wind turbines respectively. The EPON based communication network architecture has low cost, high reliability, and fair transmission capability. To evaluate the performance of proposed architectures, the wind power farm based on IEC 61850 is modelled by using OPNET The simulation results are analyzed and compared with conventional Ethernet based communication network in terms of the overhead, delay and fairness of data transmission.

• 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.