• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.156-163
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• 2015

This paper presents a new framework for design and economic evaluation of wind energy-based electricity supply system. We propose a network optimization (mixed-integer linear programming) model to design the underlying energy supply system. In this model we include practical constraints such as land limitations of onshore wind farms and different costs of offshore wind farms to minimize the total annual cost. Based upon the model, we also analyze the sensitivity of the total annual cost on the change of key parameters such as available land for offshore wind farms, required area of a wind turbine and the unit price of wind turbines. We illustrate the applicability of the suggested model by applying to the problem of design of a wind turbines-based electricity supply problem in Jeju. As a result of this study, we identified the major cost-drivers and the regional cost distribution of the proposed system. We also comparatively analyzed the economic performance of on/off shore wind farms in wind energy-based electricity supply system of Jeju.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.3
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• pp.198-204
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• 2022

In this paper, the 5kW and 50kW vertical axis wind turbines were studied using the ANSYS flow analysis simulation program. The 5 kW vertical shaft wind turbine has 30 units of the number of main blades and sub-blades and the electrical characteristics were analyzed by changing the tip speed ratio (TSR) from 0.2 to 06. A 50kW vertical axis wind turbine was designed based on the electrical characteristics of a 5kW vertical axis wind turbine. When the tip speed ratio was 0.5, the 5 kW wind power generation showed the maximum output of 9.5 kW and the efficiency of 0.28. The calculation of the power current(Ip) and the power voltage(Ep) show that, as the tip speed ratio increases, the power current(Ip) decreases and the power voltage(Ep) increases. And even if the tip speed ratio was changed, 5kW wind power generation was measured for output of 5 kW or higher. When the tip speed ratio was changed from 0.3 to 0.6, 50 kW wind power generation was output more than 50 kW. When the tip speed ratio of 50kW wind power generation was 0.4, the output was 58.37 [kW] and the efficiency was 0.318, and it was confirmed that the proposed 50kW wind power generation satisfies the design conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.664-677
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• 2014

Wind energy has proven its viability by the emergence of countless wind turbines around the world which greatly contribute to the increased electrical generating capacity of wind farm operators. These infrastructures are usually deployed in not easily accessible areas; therefore, maintenance routines should be based on a well-guided decision so as to minimize cost. To aid operators prior to the maintenance process, a condition monitoring system should be able to accurately reflect the actual state of the wind turbine and its major components in order to execute specific preventive measures using as little resources as possible. In this paper, we propose a fault detection approach which combines cluster analysis and frequent pattern mining to accurately reflect the deteriorating condition of a wind turbine and to indicate the components that need attention. Using SCADA data, we extracted operational status patterns and developed a rule repository for monitoring wind turbine systems. Results show that the proposed scheme is able to detect the deteriorating condition of a wind turbine as well as to explicitly identify faulty components.

• Journal of Environmental Science International
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• v.18 no.8
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• pp.841-845
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• 2009

In this paper, offshore wind resources within the Japan's EEZ (Exclusive Economic Zone) are assessed using wind speed data from the microwave scatterometer SeaWinds onboard QuikSCAT. At first, from the 10m-height wind speed from QuikSCAT, 60 m-height wind speed is estimated by using an empirical equation for height correction. Based on the 60 m-height wind speeds, annual energy Production is calculated under an assumption of installing 2 MW wind turbines every $0.64km^2$. The annual energy production is then accumulated for the entire Japan's territorial waters and EEZ ($4.47{\times}10^6km^2$). As a result, it is shown that the total energy Production is estimated to be $4.86{\times}10^4$ TWh/yr. This offshore wind energy Potential within the EEZ is approximately 50 times higher than the actual annual electricity production in Japan.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.94-101
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• 2012

A Dokdo wind resource map has been drawn up for the Green Island Energy Master Plan according to Korea's national vision for 'Low Carbon Green Growth'. The micro-siting software WindSim v5.1,which is based on Computational Flow Analysis, is used with MERRA reanalysis data as synoptic climatology input data, and sensitivity analysis on turbulence model is accompanied. A wind resource assessment has been conducted for the Dokdo wind power dissemination plan, which consists of two 10kW wind turbines to be installed at the Dongdo dock and Dokdo guard building. It is evaluated that the capacity factors at Dongdo dock and Dokdo guard building are about 20% and 30% respectively, and annual and hourly variations of wind power generation have been analyzed, but summertime energy production is predicted to be only 40% of wintertime energy production.

• 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.

• Ocean Systems Engineering
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• v.12 no.4
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• pp.461-477
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• 2022

Dynamic Positioning (DP) is a system that uses computer-controlled thrusters, propellers, and other propulsion devices to automatically maintain a vessel's position and heading. In this study, a wind turbine installation vessel with DP capabilities was proposed for use in mild environmental conditions in the Yellow Sea. The thruster arrangements of the vessel were analyzed in relation to wind and current loads, and it was found that a four-corner arrangement of thrusters provided the best position-keeping performance. The vessel's DP control performance was also analyzed in relation to the increased environmental load caused by the presence of a wind turbine, using a capability plot. The vessel's performance was evaluated in three different states: floating with no load, during the loading of a wind turbine and suction buckets, and after the wind turbine has been installed. The use of 750 kW and 1,000 kW thrusters was also considered, and the environmental loads in the Saemangeum coastal area and the environmental load when a 5-Megawatt wind turbine is on board were assessed. The study concluded that at least four thrusters should be used for DP to safely manage the installation process of wind turbines.

• Journal of Wind Energy
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• v.14 no.4
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• pp.75-86
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• 2023

We observed five species and 163 individuals of birds in the Demonstration Offshore Wind Farm in the southern part of the West Sea in Korea, and 33 species and 4,023 individuals from Gusipo to Dongho Beach. The most dominant bird in both areas was the black-tailed gull, Larus crassirostris. The flight height of birds for collision risk (wind turbine and bird) was divided into two groups. First, the safe height was from sea level to 20 m (< 20 m), with no effect from the action of revolving blades. Second, the danger height was more than 20 m from sea level (> 20 m), with a collision risk from the action of revolving blades. Birds flying a safe height (< 20 m) were 83.9% (271 individuals) and danger height (> 20 m) were 16.1% (52 individuals). Also, 11.7% of birds (35 individuals) used the inside of the Demonstration Offshore Wind Farm as a habitat for foraging and resting, and 88.3% birds used the outside. We suggest that the risk of collision with the wind farm was low due to the relatively low flight height of birds and distance between wind turbines (> 800 m).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.96-97
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• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.261-262
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• 2012