太陽光追蹤器因可透過轉動太陽能電池模組，使得面板朝向太陽，進而提高發電效率，故廣範用在太陽能發電之應用。追蹤器雖因不同追日方式而有不同形式的機構設計，但不論是何種形式，都仍存在有各種的機構加工、組裝以及機台現地安裝上的誤差。這些誤差對以太陽軌跡路徑為基礎，透過開迴路方向控制之被動式追蹤器影響最大。如果無法將這些誤差排除，則會使追日精度下降。特別是聚光形太陽能電池的可接受角度約在0.5?左右，故在運轉時的最大追日偏差角亦必須控制能低於0.5?。因此本研究之目的在對傾角-轉角形式的太陽光被動式追蹤器以光電位置感測器量測追日偏差角，從中找出機構固有的系統誤差，並將其納入追日控制程式中，以修正追蹤器追日運動。本研究僅考慮傾角-轉角形式追蹤器的主要系統誤差，包括追蹤器指北誤差、主軸傾角誤差、傾角機構傳動初值誤差及光電位置感測器之原點誤差。為求得前述系統誤差，追蹤器光以無誤差修正的追日模式進行追蹤，將光電位置感測器所量到的一日內誤差數據以最小平方法進行曲線擬合，以得到各項誤差值。隨後再以所得到之誤差值修正追蹤器之追日運動，並再以位置感測器量測追日偏差。實驗結果顯示，修正後的追日偏差大約在0.2?，小於修正前的最大誤差1.2?。因此通辭研究之方法可以有效改善應用聚光形太陽能電池追蹤器之追日精度。Because the solar tracker can control the direction of solar cell modules to the sun for increasing the power generating efficiency, it is widely applied in solar power generation. Although there are various types of trackers due to different tracking methods, various errors of solar trackers, including manufacturing errors, assemble errors and installation errors, can not be ignored. These errors affect strongly the solar trackers with passive control system. If these errors can not be eliminated, the tracking accuracy will decrease. Especially the acceptance angle of concentrated photovoltaic (CPV) cells is about 0.5°, so that the tracking error of trackers must be less than 0.5°. The goal of this research is to identify the system errors of the passive controlled tracker in tilt-roll type by using a position sensitive detector (PSD) measure the tracking angular error. And afterwards, the tracking algorithm can be modified with such errors so as to increase the tracking accuracy.??Only the system errors of the tilt-roll tracker, including both the aligning error to north meridian and the tilting error of the main axis, initial position error for tilting mechanism and original position error of PSD, are considered in the thesis. In order to identify these errors, the tracking errors are measured by using a PSD. The results of the conducted experiment show that tracking error of the compensated algorithm is about 0.2°, less than 1.2° by tracking without compensation. It indicates that the compensation method proposed in the thesis can improve the tracking accuracy of concentrated photovoltaic trackers.
