Fresnel聚光器的优化设计及其在聚光光伏中的应用研究

发布时间：2019-04-16 00:12

【摘要】：为提高聚光光伏技术的竞争力,急需进一步提高聚光光伏产品的性能,降低发电成本。目前,国内GaIn P/Ga In As/Ge多结聚光太阳电池的产业化效率已达到40%以上,然而聚光光伏模组的效率却远低于聚光电池的效率。分析各种非理想因素的影响,发现聚光器件是效率损失的主要来源之一。传统平板型Fresnel聚光器主要基于成像原理和单波长设计,聚光效果并不理想,主要体现在:(1)宽光谱内的色散导致了严重的截断损失,从而降低了聚光器的聚光效率;(2)存在聚焦光斑空间和光谱分布不均匀的问题,导致Ga In P/Ga In As/Ge多结电池短路电流、填充因子以及光电转换效率的降低。为充分利用Ga InP/Ga In As/Ge多结电池的高效率,需要配备性能优异的聚光器,从而提高聚光光伏模组的产业化效率。针对以上问题,本论文在国家863项目“兆瓦级高倍聚光化合物太阳电池产业化关键技术(2011AA050507)”的支持下,采用理论分析、仿真计算和实验研究相结合的方法,进行了新型Fresnel聚光器的设计研发工作,同时展开新型Fresnel聚光器在聚光光伏中的应用研究,促进了聚光光伏模组光电转换效率的提升。具体研究成果如下:1.建立了Fresnel聚光器性能表征参数的理论计算模型。引入截断损失的概念,定量分析了Fresnel聚光器的光学损失,对影响聚光效率的因素进行了详细的理论分析;基于光线追迹法,建立了聚焦光斑均匀性的理论计算模型。2.优化设计了一种适用于Ga In P/Ga In As/Ge多结太阳电池的高效均匀聚光Fresnel透镜。综合考虑AM1.5D太阳光谱、各子电池的光谱响应特性及透镜材料的折射率色散曲线,采用多波长与多焦点相结合的设计方法,对Fresnel透镜进行优化设计。基于光线追迹法,对该新型透镜的聚光性能进行评估,仿真结果表明:所设计的透镜在300~1800 nm宽光谱范围内以及各子电池光谱响应波段内的聚光分布均匀度都高于75%,聚光效率均大于80%;3.对高倍聚光光伏单元进行了电性能仿真分析及实验研究。以多结太阳电池的等效电路为基础,建立了简化的三维分布式网格电路模型,并通过LTspice+Matlab的方法实现了非均匀聚光条件下多结太阳电池I-V特性的仿真分析。将所设计的新型Fresnel透镜与GaIn P/Ga InAs/Ge多结太阳电池接收模块组成高倍聚光光伏单元,基于所建立的三维分布式网格电路模型和光线追迹法,对高倍聚光光伏单元的电学性能进行了仿真分析。仿真结果表明:所设计的新型Fresnel透镜聚光光伏单元的光电转换效率为32.4%,比点聚焦Fresnel透镜聚光光伏单元的转换效率提升了近8%。在仿真研究的基础之上,搭建了户外测试平台,对所设计Fresnel透镜的聚光性能和聚光光伏单元的电学特性进行了实际测试。4.研制出基于新型Fresnel聚光器的聚光光伏模组。通过增加大口径导光筒装置,使聚光光伏模组的接收角达到了1°以上,降低了对跟踪器精度的要求,提高了模组的可靠性。基于散热分析和成本考虑,确定了封装材料以及模组的结构。通过优化封装工艺,控制安装误差,制备了模组样品,并对其电学特性及温度特性进行了实际测试。测试结果表明:所研制的模组具有较好的输出性能,直接辐照度为850 W/m~2的条件下,转换效率达到了27.9%,最大输出功率为89.39W;同时,模组能够很好地满足实际散热需求,白天大部分时间,模组温度处于40~55℃范围内,最高温度为60.5℃。
[Abstract]:In order to improve the competitiveness of the light-gathering photovoltaic technology, the performance of the light-gathering photovoltaic product is needed to be further improved, and the power generation cost is reduced. At present, the industrial efficiency of the domestic Gain P/ Ga In As/ Ge multi-junction solar cell has reached more than 40%, but the efficiency of the concentrating photovoltaic module is far lower than that of the photovoltaic cell. The influence of various non-ideal factors is analyzed, and it is found that the condenser is one of the main sources of efficiency loss. The traditional flat-plate Fresnel condenser is mainly based on the imaging principle and the single-wavelength design, and the light-gathering effect is not ideal. (2) There is a problem that the focal spot space and the spectral distribution are not uniform, leading to the reduction of the short-circuit current, the filling factor and the photoelectric conversion efficiency of the Ga In P/ Ga In As/ Ge multi-junction cell. In order to make full use of the high efficiency of the Ga InP/ Ga In As/ Ge multi-junction cell, a condenser with excellent performance is required, thereby improving the industrialization efficiency of the light-collecting photovoltaic module. In view of the above problems, in the support of the "Key technology of the industrialization of megawatt-level high-power light-gathering compound solar cell (2011 AA050507)" of the national 863 project, this paper adopts the method of combining the theoretical analysis, the simulation calculation and the experimental research, and the design and development of the new Fresnel condenser is carried out, and the application of the new Fresnel condenser in the light-gathering photovoltaic is also carried out. And the photoelectric conversion efficiency of the light-gathering photovoltaic module is improved. The specific research results are as follows:1. The theoretical calculation model of the performance characteristic parameters of the Fresnel condenser is established. In this paper, the concept of cut-off loss is introduced, the optical loss of the Fresnel condenser is quantitatively analyzed, the factors that influence the efficiency of the light-gathering are analyzed in detail, and the theoretical calculation model of the uniformity of the focal spot is established based on the ray tracing method. An efficient and uniform light-gathering Fresnel lens for Ga In P/ Ga In As/ Ge multi-junction solar cell is designed. In this paper, the spectral response characteristics of the AMM1.5 D solar spectrum, the spectral response characteristics of each sub-cell and the refractive index dispersion curve of the lens material are comprehensively considered, and the Fresnel lens is optimized by using a combination of multi-wavelength and multi-focus. Based on the ray tracing method, the light-gathering performance of the novel lens is evaluated, and the simulation results show that the designed lens is more than 75% in the 300-1800 nm wide spectral range and the light-gathering distribution uniformity in each sub-cell spectrum response band, and the light-gathering efficiency is more than 80%; The electrical performance simulation and experimental study of the high-power-concentration photovoltaic cell were carried out. On the basis of the equivalent circuit of the multi-junction solar cell, a simplified three-dimensional distributed grid circuit model is established, and the simulation and analysis of the I-V characteristics of the multi-junction solar cell under the non-uniform light-gathering condition are realized by the method of the Lspice + Matlab. A new Fresnel lens and a Gain P/ Ga InAs/ Ge multi-junction solar cell receiving module are combined to form a high-power concentration photovoltaic cell, and the electrical performance of the high-power light-gathering photovoltaic cell is simulated and analyzed based on the established three-dimensional distributed grid circuit model and the ray tracing method. The simulation results show that the photoelectric conversion efficiency of the designed new Fresnel lens condenser photovoltaic cell is 32.4%, and the conversion efficiency of the specific point focusing Fresnel lens condenser photovoltaic cell is improved by nearly 8%. On the basis of the simulation research, an outdoor test platform is built, and the light-gathering performance of the designed Fresnel lens and the electrical characteristics of the light-collecting photovoltaic cell are actually tested. The light-gathering photovoltaic module based on the new Fresnel condenser was developed. By adding the large-diameter light guide tube device, the receiving angle of the light-collecting photovoltaic module reaches more than 1 degree, the requirement on the accuracy of the tracker is reduced, and the reliability of the module is improved. And the structure of the packaging material and the module is determined based on the heat dissipation analysis and the cost considerations. By optimizing the packaging process and controlling the installation error, the module samples were prepared, and the electrical characteristics and the temperature characteristics of the module samples were tested. The test results show that the module has good output performance, the direct irradiance is 850W/ m ~ 2, the conversion efficiency is 27.9% and the maximum output power is 89.39W; at the same time, the module can meet the actual heat dissipation demand well, and most of the day in the day. The temperature of the module is in the range of 40 to 55 DEG C, and the maximum temperature is 60.5 DEG C.
【学位授予单位】：华北电力大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TK513.1

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