摘 要 近年來因為環境污染和能源短缺的問題越來越嚴重,尋找替代能源便成為世界各國共同努力的目標。目前國外已提出多種方式可追蹤到其最大功率點(MPP),但是大多還是採用被動的追蹤方式來達到最大功率點(MPP)。 本論文是改善阻抗匹配法,使其在不同照度下皆能準確做最大功率點追蹤,並且應用阻抗匹配法在實際的太陽光能發電系統,經由調整DC-DC轉換器中的主動開關之責任週期來達到負載與太陽能板的匹配,達成最大功率傳輸。而如何有效的取得太陽電池的開路電壓及短路電流,以便正確計算出太陽電池的內部阻抗則為本論文研究重點。本論文使用改善阻抗匹配法的最大功率點追蹤技術,將能有效預知下次的最大功率點位置,使系統維持工作在最大功率點上,本論文將實驗驗證此法的可行性。
Abstract After the energy crisis breaking out, looking for the alternative energy sources has become the goal of countries all over the world. There are many proposals to make the solar energy system to work on maximum power point(MPP) , but most of them still adopt the passive method to reach the MPP. This research improves the impedance marching method, by varying duty cycle in a DC-DC converter to make the apparent load impedance matching with current system impedance, and reach the mpp operation. First , measure the open circuit voltage and short circuit current to get the current system impedance, then force the apparent load impedance to match it to make the solar system working on maximum power point. Finally, real experimental data has been used to verify the feasibility of this method.