菲涅爾透鏡聚光系統設計與模擬研究

Abstract

本論文探討平面菲涅爾透鏡應用於聚光型太陽能電池之鏡組設計與特性，主要分為三個倍率設計應用於不同太陽能電池的聚光鏡組。首先我們使用高倍率的菲涅爾透鏡為主光學元件，分析透鏡的焦距限制以及焦距長短對幾何放大倍率、接收率和接收角度的影響，然後使用方型光學導管為二次光學元件來提升系統的接收角度以及光分布均勻度，設計適合應用於III-V族太陽能電池的高倍率聚光系統，此系統於625倍的幾何放大倍率下，工作距離為95 mm的鏡組對於正負1.265度入射的光線，其理想光學效率可達87.5％以上。再來則是討論100倍幾何放大倍率的透鏡，設計適合應用於薄膜太陽能電池的中倍率聚光透鏡，我們將透鏡分成數個環狀區域改變各區域稜鏡聚焦平面的位置來提升接收面的光分布均勻度，此透鏡與接收平面之距離為66 mm，系統對於正負1.265度入射的光線可以達到95％的光學效率。最後我們針對矽太陽能電池設計3倍幾何放大倍率的透鏡，使用寬稜鏡間距的設計來減少尖端圓角造成的光學效率損失，此透鏡之焦距為90 mm，具有正負4度的接收角度。

This study analyzes the designs and properties of flat Fresnel lenses applied in refractive concentrator systems. For a high concentration ratio, the Fresnel lens design for III-V multi-junction solar cells uses a 625× geometrical concentration ratio. We use the square light tube as a secondary optical element to increase the acceptance angle and the energy distribution. The working distance is 95 mm, and the ideal optical efficiency achieves 87.5％ in ±1.265 incident degrees. Secondly, the lens for the 100× geometrical concentration ratio is applied to thin-film solar cells. We divide the lens into three cyclic zones, and each part has a different focal plane to increase the uniformity of light distribution. The acceptance angle in this medium concentration system is ±1 degree, and the ideal optical efficiency is 95％ in ±1.265 degrees with a 66 mm working distance. For the final part which uses a 3× geometrical concentration ratio, the system is designed for applications in silicon solar cells. Considering the loss of optical efficiency caused by the draft angle of the vertical facets and the roundness of vertices, we use wide prism pitches to reduce the fidelity loss of fabrication. This system’s focal length is 90 mm, and the acceptance angle is ±4 degrees.