本研究主要探討小型風能發電系統的發電效能。依照實驗設計，特別為小型風力發電機建造一座下吹式的開放型環境風洞，並利用風洞產生不同的風速，以進行風能發電系統的特性試驗，完成後將實測數據進行分析及結果討論。本研究根據CNS 7779 標準的量測方法，藉由熱線式風速計測量風洞出口測試段的風速，結果顯示平均風速範圍在1.7 ~ 9.1 m/s。由實驗得知，小型風能發電系統的功率會隨著風速增強而呈現指數型的增大，當風速於4.26 m/s 時，系統會獲得最佳的風能轉換輸出效率約16.86 Watt，利用風能係數(C p)來評估為0.42 ，此時風力發電機葉片轉數約為390 rpm ；同時實驗也發現，風力發電機葉片轉速會隨著系統阻抗的減少而產生煞車作用，當風力發電機處於6.22 m/s 的風速下穩定運轉時，葉片轉速會在488 rpm ，當系統阻抗逐漸下降到4.5 Ω 時，轉速則減慢到350 rpm 左右。總體而言六翼式阻力型風力發電機，比起傳統多翼式阻力型風力發電機的風能效率，多出10 ~ 20 %。本研究中所建構之監測系統、實驗方法及結果，可以提供未來小型風力發電系統，實驗分析所需要的概念及數據基礎。

This research aims to discuss the power generation performance of small
capacity wind energy system. A blow-down open-type wind tunnel was specifically designed for the small capacity wind turbine generator according to experimental design, and the characteristics of wind turbine generator were tested using the velocities generated by the wind tunnel, and finally the test data was analyzed and discussed. With the measurement method of CNS7779 standard, a hot-wire anemometer was used to measure the wind velocity of the test section at outlet of wind tunnel, showing that the mean velocity ranged between 1.7 ~ 9.1 m/s. The experiment found that, the power of small capacity wind turbine generator would increase exponentially with the growing wind velocity. When the wind velocity is 4.6m/s, the optimum wind energy conversion output efficiency is about 16.86 Watt; the wind power coefficient ( P C ) is evaluated as 0.42, and the number of wind turbine generator’s impeller revolution is approximate 390 rpm. This study also found that,the rotation speed of wind turbine generator’s impeller would generate braking action with the reduction of system impedance. When the wind turbine generator is operated stably at the wind velocity of 6.22 m/s, the rotation speed of impeller is 488 rpm.When the system impedance declines gradually to 4.5 Ω, the rotation speed would slow down to about 350 rpm. On the whole, six-blades resistance wind turbine generator has an efficiency 10 ~ 20 % higher than conventional multiple-blades one.
The monitoring system, experimental method and results here to can provide
necessary concept and data for experimental analysis of small capacity wind turbine generator in the future.