高倍聚光光伏模组中菲涅尔透镜沿光轴方向的光照非均匀性变化及影响

Non-uniformity of Fresnel Lens along the Optical Axis in High-concentrating Photovoltaic Module and Its Influence

对于菲涅尔透镜作为主要聚光器件的高倍聚光光伏模组,应用中通常把多结电池放置于透镜焦平面处,然而光学系统非理想性造成焦平面处的光照非均匀性,会影响三结电池及模组整体的输出特性。通过光线追踪模拟和三维三结电池网络模型,分析沿光轴方向不同位置菲涅尔透镜聚光光照非均匀性的变化,以及对高倍聚光光伏模组的影响机理和优化。结果表明沿光轴填充因子与光照非均匀性有密切关系,沿光轴不同程度的光照非均匀性导致不同程度的横向电流,填充因子随之发生变化,在远离焦平面的位置存在更优的填充因子,提升最大输出功率。实验结果也很好地验证了模拟的结果,结论对实际应用中高倍聚光光伏模组的结构优化有参考意义。

High-concentrating photovoltaic(HCPV)technology plays an important role in solar power generation due to its extremely high e ciency.However,the e ciency of the HCPV module can be reduced by many factors.In the high-concentrating photovoltaic module with Fresnel lens as the main concentrating device,the multi-junction solar cell is usually placed in the focal plane of the lens in application.However,the non-ideal optical system results in the non-uniformity of light at the focal plane,which affects the output characteristics of the multi-junction solar cell and the whole module.Therefore,the change of non-uniformity of concentrated light of Fresnel lens was analyzed in different positions along the optical axis.And the influence mechanism and optimization of high-concentrating photovoltaic module through ray tracing simulation and three-dimensional triple-junction solar cell network model were also analyzed.The results show that the filling factor along the optical axis is closely related to the light non-uniformity.Different degree of light non-uniformity along the optical axis results in different degree of transverse current,and the filling factor changes accordingly.There is a better filling factor far away from the focal plane,which improves the maximum output power.The simulation is verified by the experimental results,the output power can increase more than 12%after optimization.This study has reference significance for the structural optimization of high-concentrating photovoltaic module in practical application.