• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1272-1278
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• 2014

In this experimental study for the current growing offshore wind, a wind tunnel test was conducted to examine the performance of the vertical-type cross-flow wind turbine power generation system. Due to the limited size of the test section of the wind tunnel, the inlet guide vane of the original wind power generation was scaled down to about 1/5 and the turbine impeller diameter was also reduced to 1/2 of the prototype impeller. The number of the impeller blade is another important parameter to the output power of the wind power generation system and the number was varied 8 and 16. From the analysis of the experimental result, the output brake power of the model wind turbine was measured as 278watts with the 16-blade at 12 m/s of the rated wind speed and the rated brake power of the prototype wind turbine is calculated to 3.9kW at the rated operating condition.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.10a
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• pp.20-20
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• 1998

풍력발전용 회전날개의 구조설계 요구조건은 크게 제한 강도 요구조건(Limit strength requirement), 강성도 요구조건(Stiffness requirement), 피로수명 요구조건(Fatigue life requirement)의 세 가지를 들 수 있다. 첫째로 제한 강도 요구조건은 운용기간 중에 발생할 수 있는 최대하중에 견딜 수 있어야 하며, 폭풍이나 돌풍의 상황에 대한 안전성을 의미한다. 둘째로 강성도 요구조건은 운용 중 공진을 피하기 위한 고유진동 수확보, 타워와의 충돌을 피하기 위한 변위의 제한, 공력성능의 변화를 피하기 위한 비틀림각의 제한등이 있다 셋째로 피로수명에 대한 요구조건은 요구피로수명 동안에 예상되는 반복하중에 견딜 수 있어야 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.13-18
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• 2015

Characteristics of restoring force for the wind-powered leisure boat was investigated using mathematical formulation and commercial computational method such as the ANSYS Workbench CFX-Mesh. The objective is to find the restoring moment and heel moment while boat is sailing in windy power. Conditions for angle of attack were given from $5^{\circ}$ to $90^{\circ}$. It is known that side force is larger in terms of angle of attack is higher, however critical angle is suggested to limit before over of $60^{\circ}$ for safe navigation for boat in wind. Natural results are found that stronger heel moment is observed when sail is used than no sail, and higher angle of attack is induced stronger heel moment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1331-1337
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• 2013

This study deals with the structural optimization of hybrid vertical-axis wind turbine blades using a response surface method (RSM). The structural analysis results suggest that the stress of hybrid vertical-axis wind turbine blades exceeds the yield strength. Optimization techniques are then applied to structural design to ensure a safe structure. First, the design factors that strongly influence the structural response are identified. The RSM was applied based on the design of experiments. The objective function and constraint terms set the weight and allowable stress, respectively. Furthermore, sensitivity analysis was conducted to indicate the effects of the design factors on the stress and weight. Finally, structural design was performed for the hybrid vertical-axis wind turbine blade.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.261-262
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• 2011

본 논문은 LCL-필터를 사용하는 대용량 풍력 발전 시스템의 간단한 능동 댐핑 알고리즘을 제안한다. L-필터, LC-필터와 비교해볼 때, LCL-필터는 비교적으로 작은 인덕터 값을 이용하여 계통 전류의 고주파를 제거할 수 있지만, 공진이 발생된다. 따라서 LCL-필터 사용 시 공진보상은 필수적이다. 본 논문에서는 추가적인 센서나 수동소자의 사용 없이 개선된 DFT 알고리즘을 이용하여 능동댐핑을 수행하는 방법을 제한했고, 시뮬레이션을 통해서 성능을 입증한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.794-805
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• 2017

This paper proposes a Hardware-In-Loop(HIL) Simulator for a Wind Turbine and an operational control algorithm to evaluate the performance of a wind turbine control system. It provides not only for the validation of the control logics, safety functions and H/W failure, but also for the high reliability of the wind turbines (by reducing/and the reduction of the operating expense(OPEX) through performance evaluation tests with complex scenarios. On the other hand, the proposed simulator uses MATLAB, CODER, and the PLC library to operate in synchronization with the hardware, and a real-time processing-based wind turbine module including a dynamic model and control system, wind module, grid module and host PC to manage the HIL-simulator. Several experiments were carried out under the above concept to verify the effectiveness of the proposed WT HIL-simulator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.64-71
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• 2017

A damage estimation method is presented for jacket-type support structure of offshore wind turbine using a change of modal properties due to damage and committee of neural networks for effective structural health monitoring. For more practical monitoring, it is necessary to monitor the critical and prospective damaged members with a limited number of measurement locations. That is, many data channels and sensors are needed to identify all the members appropriately because the jacket-type support structure has many members. This is inappropriate considering economical and practical health monitoring. Therefore, intensive damage estimation for the critical members using a limited number of the measurement locations is carried out in this study. An analytical model for a jacket-type support structure which can be applied for a 5 MW offshore wind turbine is established, and a training pattern is generated using the numerical simulations. Twenty damage cases are estimated using the proposed method. The identified damage locations and severities agree reasonably well with the exact values and the accuracy of the estimation can be improved by applying the committee of neural networks. A verification experiment is carried out, and the damage arising in 3 damage cases is reasonably identified.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.635-641
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• 2019

Domestic southwest offshore wind farms have problems such as the reduction in fishing rights by prohibiting vessel traffic, which delays their development. As such, there is a need to develop offshore windfarms in Europe to permit the passage of vessels and fishing operations in specific offshore windfarm areas. In this study, we used the environmental stress (ES model) and the IALA Waterway Risk Assessment Program (IWRAP) to determine the ratio of risk to the route type (cross pattern, grid pattern) and traffic volume (present, 3 times, 5 times and 10 times) to derive the risk factors of specific vessels for offshore windfarms. As a result, ship operators' risk related to offshore windfarms did not rise in both route types and there was no significant difference in the annual probability of collision in the present traffic volume. In conditions that increased traffic volume by 3 times, 5 times and 10 times, the risk ratio increased as ship operator risk and collision probability increased at the crossing points. Furthermore, when the traffic volume of the ship increased, the risk could be more effectively distributed in the grid route compared to the cross route. The results of this study are expected to apply to the operation type, route operation method, safety measures, etc. in offshore wind farms.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.83-86
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• 2008

정부는 2006년 8월 기존의 발전차액 지원제도를 개정하여 발전차액 기준가격 지원대상 확대, 적용기간의 15년 단일화, 수력, 바이오에너지는 고정요금과 변동요금 중에서 선택할 수 있는 선택권 부여, 기술발전에 따라 태양광, 풍력, 연료전지는2-3년간의 유예기간 이후 매년 감소율을 적용하여 기준가격을 낮추는 등 많은 제도개선 내용을 반영하였다. 2006년 10월부터 개정된 발전차액 지원제도가 시행된 이후 태양광, 풍력의 신규진입이 대폭 증가하였고 수력, LFG, 바이오가스는 대부분 변동요금을 신청하였으며 2007년 집행된 신재생에너지 발전차액 기반기금의 55% 이상이 태양광발전에 지급되는 편중현상의 영향이 나타났다. 따라서 변동요금 설계시보다 SMP 평균이 22원 이상 높아져 변동요금의 재설계, 태양광 발전의 기반기금규모가 55% 이상을 점유하고 있으며 향후 더욱 심화될 예정이므로 특정전원의 기반기금 점유비중 제한 및 최근 수년간 준공된 신재생에너지의 운영실적을 분석하고 법적요건을 상세히 검토하여 투자비, 운영비, 이용률등을 재조정하여 기준가격을 합리적으로 개정하여 제2의 신재생에너지 도약기를 마련해야 할 것이다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.1971-1979
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• 2010

As a result of increasing environmental concern, the penetration of renewable power on power systems is now increasing. Wind energy can be considered as the most economical energy sources to generate electricity without depletion of fossil fuel. To devise adequate control strategies for wind farm, time domain simulation analysis needs to be performed. This presents a continuation time integration (CTI)-based time domain simulation algorithm for wind farm with doubly fed asynchronous generator (DFAG) connected to the external power systems. This paper depicts how to time trajectories are traced using CTI-based time domain simulation. Also this paper describes the possibilities of hierachical control for wind farm output limitation, and the coordinated control has been designed by hierarchical control structured from central control level to wind farm control board and to an individual wind turbine level. Finally it shows an illustrative example of time domain simulation result with two test systems through case study.