基于线聚焦菲涅耳透镜的空间聚光光伏系统特性的实验研究

Experimental Research on Characteristics of Space Concentrating Photovoltaic System Based on Linear Focusing Fresnel Lens

对线聚焦菲涅耳透镜的空间聚光光伏系统的特性开展了实验研究,以期解决工程设计时多参数合理匹配和选择的问题。通过研制由菲涅耳透镜—单晶硅太阳电池光伏组件、太阳模拟器和测试设备组成的实验装置,开展了菲涅耳透镜失焦距离、聚光比和太阳电池短路电流、开路电压、最佳功率、填充因子、效率、温度等之间的关系以及不同失焦距离和不同太阳光线横向偏角对聚焦宽度的影响的实验测试和实验分析工作。研究结果表明:聚光太阳电池性能随短路电流和最佳功率的提高而提高,短路电流和最佳功率分别随聚光比的增加而近似呈线性增大,开路电压基本不随聚光比变化;失焦距离变化引起透镜聚焦宽度变化,进而影响电池表面辐射强度和有效聚光比,应控制失焦距离在可允许范围内;太阳电池串联电阻对聚光太阳电池工作性能存在不利影响,需尽可能选择低串联内阻、高填充因子的太阳电池;应保证聚光太阳电池具有良好的散热条件;太阳光线横向偏角会导致聚焦宽度变大、聚光比减小,并使聚焦光线偏离太阳电池,应控制横向偏角在规定范围内。研究结果为线聚焦菲涅耳透镜空间聚光光伏系统工程设计提供了技术支持。

The experimental research is carried out to testify the performance of space concentrating photovoltaic system based on linear focusing Fresnel lens. The experimental system is composed of Fresnel lens-silicon cell module, solar simulator, test devices, and so on. Based on this platform, the interactional relationships among defocusing distance, concentrated ratio, short circuit current, open-circuit voltage, maximum power output, the fill factor （Cg）, efficiency, temperature of cell and substrate structure, and effect of transverse tracking errors on target width are tested and analyzed. The results show that the performance improvement of concentrating photovohaic system mainly results from the increase of short-circuit current and maximum power output, and both increase linearly with the increase of concentrated ratio, while the open-circuit voltage is almost unchanged. Defocusing distance makes changes of target width, which further influences the cell surface＇ s radiation strength and effective concentrated ratio. The series resistance is a disadvantageous factor for the performance of concentrating solar cell, so we need to select solar cell with lower series resistance and higher C^-, and solar cell with good radiator. Transverse tracking errors lead to wider target, lower concentrated ratio, and the central line of target width offsetting the central line of image plane with δ = 0°. Research results above provide a significant guidance for the design of space concentrating photovoltaic system based on linear focusing Fresnel lens.