- 學位論文
外傘頂洲離岸風速垂直分布分析及風能評估
Vertical Distribution and Efficient Energy of Offshore Wind Velocity at Waisanding Sand Bar
摘要
本文使用外傘頂洲風速塔高度10公尺、30公尺、50公尺及60公尺，分析全年分析外傘頂洲風速風向特性及評估風力發電可行性。計算各高度平均風速約在7 m/s~7.8 m/s間，以National Renewable Energy Laboratory的指標此處風場乃屬於優良的。當地風機全年可運轉的比例約達82%，主要風向方位集中於北到東北，佔全年風向的55%以上，而南南東到南南西次之，占15% ~18%。 測試Weibull、Bimodal Weibull與Extended Generalized Lindley三種機率密度分布的風速配套，不同高度風速的最適機率分布，以Bimodal Weibull在三者中是最佳的。 選取高度不同所計算的風切係數不同，再推估風速結果會有差異，經評估最適於推估當地風速的高度組合為60/50與50/10。使用迴歸分析求得風力機Enercon E126 EP4性能曲線，配合最適配分布的Bimodal Weibull計算各高度發電量，其發電量隨高度增加平均風速上升而增加，最大可轉換發電量可達6,195,600 watt，理論計算發電量達1,758,700 watt，此值大於率定風速可產生的電能，而風機效率約在28%~30%間。
並列摘要
Offshore wind data of Waisanding Sand Bar in Chiayi at different heights of 10 m, 30 m, 50 m and 60 m were analyzed to have basic statistics, best fitting of wind distribution and efficient wind power generation in this paper. Mean wind speed ranged between 7 m/s -7.8 m/s were evaluated to indicate this place being an excellent wind field based on the evaluation index of National Renewable Energy Laboratory. Annual operation ratio of local wind turbines is about 82%. Dominant wind direction is from north to northeast and the proportion exceeds 55% of the total. Secondary direction is from south southeast to south southwest and the proportion is about 15% to 18% of the total. Examination of best fitting for wind data at different heights by Weibull, Bimodal Weibull and Extended Generalized Lindley functions showed that Bimodal Weibull function is the best among three distributions for all cases. The wind shear coefficient of wind speed profile expressed by a power law can be obtained by the least squared method from wind data at some chosen heights. The best choice is by the combination of 60/50 m and 50/10 m to calculate the wind speed at 10 m height. Regressed the fifth-order polynomial for the performance function for Enercon E126 EP4 associated with bimodal Weibull function was used to calculate wind energy. The results showed that the maximum convertible power generation can reach 6,195,600 watts and the theoretical calculation power generation can reach 1,758,700 watt. The wind turbine efficiency is about 28% to 30%.