| 摘要: | 由於III-V 族多接面太陽電池的效率不斷提升（目前已超過40％），使得高聚光型太陽光發電（High Concentration Photovoltaics, HCPV）系統被看好在未來的太陽能市場將急遽成長並佔有一席之地。雖然III-V 族太陽電池成本較高，然而搭配光學集光機構將太陽光聚集到小面積的電池上，可大幅降低電池使用面積而達到降低發電成本的目的。為了提高HCPV 系統的發電效率，需要搭配一精度良好之太陽追蹤器，使其太陽電池隨時精準地正對太陽，此追蹤器的組成除了結構本體、運動機構及控制元件外，尚需承載光學接收器模組而組合成一精確的追日集光系統。由於此追日集光系統，有其一定的尺寸與重量，安裝在戶外或是屋頂，除受其本身重量作用產生之應力與應變外，在日常運轉過程中，遇強風或是颱風也會產生不可忽視的瞬間外力負荷，造成額外的應力與形變。因此，在設計光學接受器模組與太陽追蹤器之整體組合結構裝置時，除了確保追蹤器的結構強度需符合安全要求之外，亦要確保結構本身重量與外在負荷所造成的結構形變，仍能維持追日精度在容許的範圍內，所以開發一套電腦輔助的 HCPV 追日集光系統結構強度與形變分析技術，將可減少反覆試誤之實體製作流程所需的時間，大大降低HCPV 系統的開發成本。本研究宗旨乃在開發一套以有限元素分析方法（FEA）為基礎之HCPV 追日集光系結構強度與形變分析技術，作為國內開發HCPV 系統之參考。本研究初期將以中央大學及台達電研究團隊所設計製作之追日集光系統作為分析對象，依此建立一套電腦輔助結構強度與形變分析技術所需之模型，並使用專業級有限元素分析軟體進行求解。有限元素分析模型將建構完整的HCPV 追日集光系統之3-D 模型，其中包含光學接收器模組、追蹤器機構及底座等各項結構元件之結合，並模擬運轉情況給予不同組合的邊界條件，如風速大小、仰角和方位角等，以進行求解並藉此分析其結構強度與追日誤差量。此外，並將於實體選擇適當位置黏貼應變規，及利用PSD 位置感測器量測追日精度的誤差量，配合風速資料和所量得之實驗數據，與數值分析解做比對，以驗證有限元素分析模型的正確性與適用性。建立此分析技術後，將可進一步配合核能研究所需求，協助其在設計更大尺寸HCPV 系統時，評估其所設計的HCPV 追日集光系統的結構安全與形變所造成追日精度的誤差量。 ; Due to the availability of highly efficient III-V multi-junction cells (> 40% efficiency), the market for high concentration photovoltaics (HCPV) seems ready to take off and grow rapidly. Concentrator solar cells differ from conventional ones in the way that they use optics to focus sunlight on a small receiving solar cell and extract more current per unit of area. Further, as the solar cells are a small part of the cost of the concentrator they can afford to be more expensive to be more efficient. To maintain a very high efficiency of the concentrator solar cells, it is required that direct sunlight is always focused on the cells and hence an automatic sun tracking assembly is incorporated into the HCPV system. Attached with concentrator modules, a sun tracker is basically composed of structural elements, moving mechanisms, and control components to make the sunlight is properly focused on the cells. For design of a cost-effective sun tracking assembly with a high precision in tracking the sun, it is required that its structure should be able to withstand the peak external loads, such as weight and wind loads, and keep its deformation below a certain threshold such that the acceptance angle losses of its concentrator modules remain within certain tolerable bounds. Therefore, a computer-aided engineering (CAE) analysis technique is necessary for success and time-saving in development of a sun tracking assembly for HCPV. The aim of this study is, by using finite element analysis (FEA), to develop a CAE technique to characterize the structural integrity and deformation in a sun tracking assembly for HCPV, which is being developed jointly by the National Central University and Delta Electronics, Inc. A complete 3-D FEA model for the sun tracking structure attached with concentrator modules will be constructed to solve the stress and strain distribution under various combinations of service conditions including wind speed, azimuth angle, and elevation angle. Estimation of the structural integrity and acceptance angle loss induced by structural deformation can then be made based on the simulation results. In addition, strain gages and a position sensitive detector (PSD) will be employed to measure the deformation at selected locations in the sun tracking assembly as well as the amount of tracking error during operation to compare with the numerical analysis results. Based on the numerical and experimental results, a cost-effective analysis technique for design of a sun tracking assembly in HCPV system will be developed and applied to a larger-scale HCPV system being developed at the Institute of Nuclear Energy Research (INER). ; 研究期間 9801 ~ 9812 |
