本研究以風洞實驗的方式探討風力機在穩態風場、特定頻率陣風風場與格網紊流風場中的發電情形，並針對兩種不同的風力機：阻力型的Rutland 913風力機以及升力型的Air-X風力機比較其性能。研究結果顯示：升力型之風力機的翼端速度比會較高，且會有較佳之發電效率；但是阻力型之風力機則有啟動風速較低及較安靜的優點，所以較適合設置於地狹人稠的都市地區。而非穩態風場中的發電情形，本研究以準穩態假設(Quasi-Steady Hypothesis)計算風力機之發電量，並與實驗之結果與進行比對，結果顯示由於風力機的動態特性，所以準穩態假設會高估風力機在非穩態風場中的發電量，本研究利用頻譜分析對準穩態假設進行修正，並對於紊流風速變化頻率高於風力機可反應頻率予以修正，再將其代入準穩態假設可得到較佳的結果。本研究之結果可幫助吾人瞭解風力機在非穩態風場中的發電情形有進一步的瞭解，可供相關工程設計之參考。 This experimental study investigates the output power of wind turbines in different approaching flows, which include steady flow, periodically varying flows and grid-generated turbulent flows. The experiment is carried out in a large-scale atmospheric boundary layer wind tunnel. The wind turbines consist of a drag-type turbine (Rutland 913) and a lift-type turbine (Air-X). The experimental results demonstrate that the lift-type turbine has higher tip speed ratio and better efficiency than the drag-type turbine. But the drag-type turbine has lower cut-in speed and is much quiet for installing in urban area. Moreover, the power outputs of wind turbines in unsteady flows are higher than in steady flows, but the quasi-steady hypothesis over-estimated the increase. Therefore, a spectral transfer function is developed to modify the power predictions, taking into account the response frequency of turbines. The modified model can be used to predict the power output of turbine in unsteady turbulent wind.
