• 해양환경안전학회지
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• 제14권3호
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• pp.205-210
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• 2008

화석연료 사용으로 인한 환경오염 및 에너지원가 상승이 큰 문제로 대두되고 있는 현재의 상황을 타개하기 위한 하나의 방안으로 신 재생에너지에 대한 관심이 고조되고 있다. 특히 서해안에 위치하고 있는 새만금 지역은 광활한 면적과 서북서풍이라는 큰 장점을 가지고 있어 풍력발전의 적지로 예상된다. 본 연구는 이러한 예상을 뒷받침해 줄 수 있는 풍력자원을 조사한 것으로 군산지역의 평균풍속은 4 m/s 정도이며, 도서지방을 연계하는 해상풍력발전 단지의 최적지로 손색이 없음을 밝혔다. 또한, 풍력자원의 출현밀도를 판별하는 Weibull의 분포함수를 이용하여 계산하고, 형상계수를 매개변수로 하여 풍속밀도계산을 한 결과, 군산지방의 풍속출현을 예상할 수 있었다.

• 한국항공우주학회지
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• 제49권12호
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• pp.963-969
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• 2021

풍력발전단지 위치 선정에 있어 풍속 분포 및 발전량을 평가하기 위해 해당 지역의 기상 타워에서 계측된 바람 자료를 이용한다. 그러나 기상 타워에서 계측된 바람 자료는 종종 정보가 누락되거나 원하는 높이에 맞지 않거나, 혹은 데이터 길이가 충분하지 않아 풍력터빈 제어 및 성능 시뮬레이션 수행에 어려움을 겪게 된다. 따라서 풍력터빈 혹은 발전단지에 대한 연간 발전량 및 이용률을 평가하는데 원하는 높이에서 장기간의 연속적인 바람 자료는 매우 중요하다. 또한, 한반도와 같이 계절에 따른 풍향과 풍속 변동이 뚜렷한 경우에는 계절별 특징이 고려된 풍속과 풍향을 동반한 바람 자료를 고려해야 한다. 본 연구에서는 통계적 방법인 은닉 마르코프 모델을 이용하여 풍속과 풍향의 변동을 고려한 인공 바람을 생성하기 위한 방법을 제시한다. 통계처리를 위한 바람 자료는 전라북도 고군산군도에 있는 말도의 기상청 방재기상관측(AWS) 장비에서 계측된 자료를 사용한다. 은닉 마르코프 모델에 의해 생성된 인공 바람은 통계 변수, 풍력에너지밀도, 계절별 평균 풍속, 주 풍향 등을 계측 자료와 비교를 통해 검증하기로 한다.

• 한국태양에너지학회 논문집
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• 제31권3호
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• pp.89-94
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• 2011

In this study, we measured the wind data as new and renewable energy resources and carried out the evaluation of uncertainty about these data with the authentic standards. These data collected at the 20 locations in korea. We carried out the processing and evaluation about these data with standards as ISO, GUM, and IEC. Whereby these data become standards data and the credibility are gained. These data include some information as direction, humidity, pressure, temperature, and energy density. The annual average of wind speed(in Hamo) was measured as 9.5m/s, then the uncertainty was evaluated as ${\pm}0.88m/s$. We judge the credibility of data by expression of reliability quantitatively. In additional, the standards data is able to approach anywhere and it will be used to support of related research and industry.

• 대기
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• 제26권3호
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• pp.373-386
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• 2016

The future variability of Wind Energy Density (WED) over the Korean Peninsula under RCP climate change scenario is projected using ensemble analysis. As for the projection of the future WED, changes between the historical period (1981~2005) and the future projection (2021~2050) are examined by analyzing annual and seasonal mean, and Coefficient of Variation (CV) of WED. The annual mean of WED in the future is expected to decrease compared to the past ones in RCP 4.5 and RCP 8.5 respectively. However, the CV is expected to increase in RCP 8.5. WEDs in spring and summer are expected to increase in both scenarios RCP 4.5 and RCP 8.5. In particular, it is predicted that the variation of CV for WED in winter is larger than other seasons. The time series of WED for three major wind farms in Korea exhibit a decrease trend over the future period (2021~2050) in Gochang for autumn, in Daegwanryeong for spring, and in Jeju for autumn. Through analyses of the relationship between changes in wind energy and pressure gradients, the fact that changes in pressure gradients would affect changes in WED is identified. Our results can be used as a background data for devising a plan to develop and operate wind farm over the Korean Peninsula.

• 전기전자학회논문지
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• 제22권2호
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• pp.460-475
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• 2018

In the variable-speed wind energy system, to achieve maximum power point tracking (MPPT), the wind turbine should run close to its optimal angular speed according to the wind speed. Non-linear control methods that consider the dynamic behavior of wind speed are generally used to provide maximum power and improved efficiency. In this perspective, the mechanical power is estimated using Kalman filter. And then, from the estimated mechanical power, the wind speed is estimated with Newton-Raphson method to achieve maximum power without anemometer. However, the blade shape and air density get changed with time and the generator efficiency is also degraded. This results in incorrect estimation of wind speed and MPPT. It causes not only the power loss but also incorrect wind resource assessment of site. In this paper, the adaptive maximum power point tracking control algorithm for wind turbine system based on the estimation of wind speed is proposed. The proposed method applies correction factor to wind turbine system to have accurate wind speed estimation for exact MPPT. The proposed method is validated with numerical simulations and the results show an improved performance.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.820-826
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• 2014

It is well known that energy generated by a wind generator (WG) depends on the wind resources at the installation site. In other words, a WG installed in a high wind speed area can produce more energy than that in a low wind speed area. However, a WG installed at a low wind site can produce a similar amount of energy to that produced by a WG installed at a high wind site if the WG is designed with a rated wind speed corresponding to the mean wind speed of the site. In this paper, we investigated the power curve of a WG suitable for Korea's southwestern coast with a low mean wind speed to achieve a high capacity factor (CF). We collected the power curves of the 11 WGs of the 6 WG manufacturers. The probability density function of the wind speed on Korea's southwestern coast was modeled using the Weibull distribution. The annual energy production by the WG was calculated and then the CFs of all of the WGs were estimated and compared. The results indicated that the WG installed on the Korea's southwestern coast could obtain a CF higher than 40 % if it was designed with the lower rated speed corresponding to the mean wind speed at the installation site.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.382-383
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• 2018

To increase the efficiency of a wind energy conversion system (WECS), the maximum power point tracking (MPPT) algorithm is usually employed. This paper proposes an optimal MPPT algorithm which tracks a sudden wind speed change condition fast. The proposed method can be implemented without the prior information on the wind turbine parameters, generator parameters, air density or wind speed. By investigating the directions of changes of the mechanical output power in wind turbine and rotor speed of the generator, the proposed MPPT algorithm is able to determine an optimal speed to achieve the maximum power point. Then, this optimal speed is set to the reference of the speed control loop. As a result, the proposed MPPT algorithm forces the system to operate at the maximum power point by using a three-phase converter. The simulation results based on the PSIM are given to prove the effectiveness of the proposed method.

• 한국대기환경학회지
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• 제21권1호
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• pp.63-72
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• 2005

In order to understand regional wind characteristics and to estimate offshore wind resources, a wind map of the Korean Peninsula was established using remote-sensing data from the satellite, U.S. NASA Quik SCAT which has been deployed for the Sea Winds Project since 1999. According to the linear regression result between the wind map data and in-situ marine-buoy data, the correlation factor was greatly improved up to 0.87 by blending the remote-sensing data of Quik SCAT with U.S. NCEP/NCAR CDAS reanalysis data to eliminate precipitation interference and to increase temporal resolution. It is found from the established wind map that the wind speed in winter is prominent temporally and the South Sea shows spatially high energy density over the wind class 6. The reason is deduced that the north-west winds through the Yellow Sea and the north-east winds through the East Sea derived by the low pressure developed in Japan are accelerated passing through the Korea Channel and formed high wind energy region in the South Sea; the same trends are confirmed from the statistical analysis of the meteorological observation data of KMA.

• 한국해안·해양공학회논문집
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• 제27권4호
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• pp.266-273
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• 2015

본 연구에서는 국내 서해안의 해상풍력 발전을 위한 적지를 검토하기 위해 기상청에서 제공하는 6개 지점(서수도, 가대암, 십이동파, 갈매여, 해수서, 지귀도)의 2014년 연간 풍속 자료를 수집하고 이를 분석하였다. 관측된 풍속 자료는 Rayleigh 모델과 Weibull 모델에 적합하였으며, 풍속 출현빈도에 따라 연간 부존량을 추정하였다. 풍력발전기 모델로는 GWE-3kH(3 kW급) 터빈과 GWE-10KU (10 kW급) 터빈을 선정하였으며 이의 성능곡선을 이용하였다. 그 결과, 서수도, 가대암, 십이동파, 갈매여, 해수서, 지귀도의 연평균 풍속은 각각 4.60, 4.5, 5.00, 5.13, 5.51, 5.90 m/s로 나타났으며, 연간 발전량은 10,622.752, 11,313.05, 13,509.41, 14,899.55, 17,106.13, 19,660.85kWh로 나타났다. 6개 지점의 연평균에너지 밀도는 전체적으로 poor와 marginal 계급으로 나타났으며, 터빈 이용률은 지귀도가 22.44%로 가장 높게 나타났다.

• Wind and Structures
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• 제14권3호
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• pp.253-283
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• 2011

This paper presents the field measurement results of wind effects on a super-tall building (CITIC Plaza, 391 m high) located in Guangzhou. The field data such as wind speed, wind direction and acceleration responses were simultaneously and continuously recorded from the tall building by a wind and vibration monitoring system during two typhoons. The typhoon-generated wind characteristics including turbulence intensity, gust factor, peak factor, turbulence integral length scale and power spectral density of fluctuating wind speed were presented and discussed. The dynamic characteristics of the tall building were determined based on the field measurements and compared with those calculated from a 3D finite element model of the building. The measured natural frequencies of the two fundamental sway modes of the building were found to be larger than those calculated. The damping ratios of the building were evaluated by the random decrement technique, which demonstrated amplitude-dependent characteristics. The field measured acceleration responses were compared with wind tunnel test results, which were found to be consistent with the model test data. Finally, the serviceability performance of the super-tall building was assessed based on the field measurement results.