• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.10
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• pp.901-906
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• 2010

A three-dimensional flow simulation was performed to investigate the flow field in a wind farm on a complex terrain. The present study aims to examine the effects of mountainous terrain and turbine arrangement on the performance of wind power generation. A total of 49 wind turbines was modeled in the computational domain; detailed blade shape of the turbines was considered. Frozen rotor method was used to simulate the rotating operation. The torque acting on the turbine blades was calculated to evaluate the performance of the wind turbines. The numerical results showed details of the flow structure in the wind farm including the velocity deficit in the separated flow regions; this velocity deficit was due to the topographical effect. The effect of the wake induced by the upstream turbine on the performance of the downstream wind turbine could also be observed from the results. The methodology of the present study can be used for selecting future wind-farm sites and wind-turbine locations in a selected site to ensure maximum power generation.

• Journal of the Korean Solar Energy Society
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• v.33 no.3
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• pp.1-8
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• 2013

In order to identify positive or negative effect of seawall on wind turbine, a wind tunnel experiment has been conducted with a 1/100 scaled-down model of Goonsan wind farm which is located in West coast along seawall. Wind speedup due to the slope of seawall contributed to about 3% increment of area-averaged wind speed on rotor-plane of a wind turbine which is anticipated to augment wind power generation. From the turbulence measurement and flow visualization, it was confirmed that there would be no negative effect due to flow separation because its influence is confined below wind turbine blades' sweeping height.

• Journal of Wind Energy
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• v.9 no.4
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• pp.40-46
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• 2018

In this study, a three-dimensional Navier-Stokes simulation around Wido Island was performed to analyze the wake effect behind an island. A 10 m/s wind speed and pressure boundary conditions were assigned for the inflow and outflow boundary conditions, respectively. Wido Island was modeled using GIS data. A prevailing wind from the north-northwest direction was determined based on QuikSCAT satellite data. A computational domain of $40km{\times}20km{\times}5km$ covering Wido Island was applied for numerical analysis. Sixty points were specified to extract the wind speed data. A wind speed profile inside the atmospheric boundary layer was compared with a wind profile using a simple power law. It turns out that the wake effect decreases the mean wind speed by 5% more or less, which corresponds to a 14% decrease in wind energy. Thus, the installation of a meteorological mast or development of a wind farm behind Wido Island is not highly recommended.

• New & Renewable Energy
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• v.16 no.2
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• pp.20-27
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• 2020

According to "The Renewable Energy 3020 Implementation Plan", offshore wind power accounts for 12 GW of the total new capacity of 48.7 GW. Like the south-west 2.5 GW offshore wind farm case, government-led development has had difficulty in securing the residents' acceptability. This study contributes to the study of local acceptance by analyzing the perceptions of Maldo residents. To this end, in-depth interviews were conducted with the head of a village and fishing village chief, and the entire contents of the interview were revised and analyzed. The cognitive structure of the stakeholders could be confirmed using semantic network analysis, which analyzes the network structure among words. Based on the analysis results, focusing on the identity frames related to the compensation process from previous national projects, gain vs. loss frames act as the dominant frame in terms of profits from offshore wind turbines. To invigorate offshore wind farms, the policy implications as follows. First, a negotiation organization should be organized to deal with strategic opposition by fishes. Second, installing offshore wind farms on a public water body will result in demands for compensation from various actors, and a licensed fishing territory as an offshore wind farm installation site should be considered.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.41-46
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• 2006

Generation of electricity using wind power has received considerable attention worldwide in recent years. In order to investigate the impacts of the integration of wind farm into utilities' network, various studies have been investigated. One such impact is related to the Critical Clearing Time (CCT) of wind power generation system. This paper reports investigation into the factors that influence the transient behavior of the wind power generation system following network fault conditions. It is shown that CCT can be affected by various factors contributed by the network. Such factors include capacity of wind power, power factor, the length of the interfacing line, etc. This investigation is conducted on a simulated grid-connected wind farm using Digsilent Power Factory.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.239-240
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• 2015

This paper presents the transient state characteristic and single phase ground fault occurred by deterioration of surge arrester when offshore wind turbine is struck by lightning strike. The wind turbine and submarine cable data are based on the 2.5GW offshore wind farm planned in South Korea Southwest Seashore. During lightning strikes, additional ground fault can lead to damage of the generation components. So, the sensitive analyses are conducted in order to investigate the effects of lightning strike on offshore wind farm.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.338-341
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• 2003

This paper proposes the adaptive relaying algorithm of protective devices applied in the neighboring distribution feeders for reliable and efficient operations of a wind farm interconnected with distribution networks by dedicated lines. Generally, it would be highly possible that the wind turbine generators are influenced by abnormal grid conditions such as disturbances occurring in the neighboring distribution feeders as well as the dedicated power line. The delayed operation time of protective devices for satisfying the coordination might overly expose the interconnected wind turbine generators to the fault and cause damage to them. In order to reduce the damages on the interconnected wind farm about the faults happening in distribution networks, this paper describes the proper delayed operation time of protective relay.

• 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.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.86-100
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• 2014

The purposes of this study are to provide a guideline for the suitability of wind farm facilities in forest lands and to suggest improvement plans of policies and systems to minimize the damage of forest lands. First, we implemented a literature review and field surveys to examine and select factors for the suitability of wind farm facilities in forest lands. Spatial database for selected location factors of wind farm facilities in forest lands was constructed to develop the suitability model for locating wind farm facilities focusing on Gangwon-do. Data used in this study include wind power resource, legal mountainous preserved area, forest roads, developed areas, forest class, and other spatial data. In order to find specific-sized potential areas for a certain number of wind farm turbines, we used block statistics and focal statistics methods. As a result, the areas for potential wind farm locations were 1,261ha from a block statistics method and 1,411ha from a focal statistics method. Based on the outputs of this research, it is required to make an urgent solution for the prevention of forest disaster and to prepare reduction measures for the destruction of ridge landscape.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.9
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• pp.735-742
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• 2015

In this paper, we compare and verify the prediction accuracy and feasibility for wind resources on a wind farm using the Weather Research and Forecasting (WRF) model, which is a numerical weather-prediction model. This model is not only able to simulate local weather phenomena, but also does not require automatic weather station (AWS), satellite, or meteorological mast data. To verify the feasibility of WRF to predict the wind resources required from a wind farm pre-feasibility study, we compare and verify measured wind data and the results predicted by WAsP. To do this, we use the Pyeongdae and Udo sites, which are located on the northeastern part of Jeju island. Together with the measured data, we use the results of annual and monthly mean wind speed, the Weibull distribution, the annual energy production (AEP), and a wind rose. The WRF results are shown to have a higher accuracy than the WAsP results. We therefore confirmed that WRF wind resources can be used in wind farm pre-feasibility studies.