分布式焦点法线聚焦菲涅耳聚光器设计及性能分析

Design and analysis of the line focus Fresnel concentrator based on the diffused focal points method

在聚光型光伏系统中,聚光光斑的幅照度不均匀性会降低光伏电池的光电转换效率;并且造成光斑局部点的能量过高,灼伤光伏电池。根据非成像光学理论,介绍了一种基于分布式焦点法设计线聚焦菲涅耳聚光器的方法,并与传统采用共焦法设计的线聚焦菲涅耳聚光器进行了对比分析。结果表明:在保证能量聚光比以及最大能量透过率不变的情况下,使用分布式焦点法设计的菲涅耳聚光器可使聚光光斑的辐照度均匀性得到很大改善,有利于提高光伏电池的光电转换效率,延长光伏电池的使用寿命。

The photovoltaics system efficiency will be improved and the system cost can be saved by using the concentrate optics system.The concentrated photovoltaics will become more important in future.However,the nonuniform illumination distribution on the cell will reduce the solar-to-electric power conversion efficiency and decrease the service life of the cell in concentration photovoltaic system.Moreover,the temperature on the cell will increase quickly which may break the cell.Based on the non-imaging optics and diffused focal points method,the method of line focus fresnel concentrator was presented to resovle the problems above,in which the angle of working face would not increase or decrease ever.By analyzing the difference between the traditional design methods and the diffused focal points method,the result indicates that under the same optical concentration and the permeance rate the new method can improve the irradiance uniformity and the photoelectric transform efficiency and extend the service life of cell.