Concentrating System’s Design and Performance Analysis for Spacial Solar Array

空间太阳电池聚光系统设计及性能分析研究

Received: 8 May 2017

Abstract

A large area of sunlight onto solar cells is gathered by concentrating system for spacial concentrating solar array, which reduces the amount of solar cells by increasing light intensity onto the solar cells of the unit area. Under concentrating conditions, the short-circuit current, open-circuit voltage, fill factor, efficiency, operating temperature and strong thermal-electrical coupling characteristics of concentrating solar cells are different from the conventional solar cells because of the high intensity and high operating temperature. The concentrating module design, solar cell selection, and design of solar cell heat-dissipation have been carried out. The thermal-electric coupling model of special concentrating photovoltaic system has been established. The relationships among concentrated ratio, substrate-thickness, thermal conductivity of substrate-material and solar cell’s temperature, density of short-circuit current, open-circuit voltage, maximum output power have been analyzed, which provide a view to a reasonabl0e match and selection of multi-parameters in engineering design. Results show that the concentrated ratio has an overall effect on the open-circuit voltage, short-circuit current, efficiency and operating temperature of the solar cell. There is a strong coupling relationship among the parameters, and the positive and negative impacts caused by the concentrating characteristics should be weighed in the engineering design. The short-circuit current density of concentrating solar cells is proportional to the concentrated ratio. Under the lower concentrated ratio circumstance, fill factor and efficiency is not substantially affected by the concentrated ratio. The maximum output power and open-circuit voltage increase with the increase of concentrated ratio. Temperature of concentrating solar cells has an adverse effect on the open-circuit voltage, efficiency and output power, which needs high efficient radiator measures to be taken. The operating temperature of solar cells could be decreased significantly by the high thermal conductivity of the substrate-material. The concentrated ratio between 9~15 is recommended for spacial solar array, which not only embodies the advantage of concentrator like improving the cell-efficiency and decreasing the cost, but also doesn’t exact the deploying precision of concentrating system.

摘要

空间聚光太阳电池阵通过聚光透镜将大面积太阳光聚集到太阳电池片上，以提高单位面积电池片接收光强，从而减少电池片使用量、降低成本。在聚光条件下，高光强、高温度特征使聚光太阳电池短路电流、开路电压、填充因子、转换效率、工作温度以及热-电耦合特性等不同于常规太阳电池。开展了聚光太阳电池模块聚光透镜、太阳电池和电池散热设计，建立了空间太阳电池聚光系统热电耦合计算模型，分析了聚光比、基板厚度、基板材料导热率与电池温度、短路电流、开路电压、输出功率间的关系，以解决空间太阳电池聚光系统工程设计中的多参数合理匹配和选择问题。研究表明：聚光比对太阳电池开路电压、短路电流、转换效率及工作温度存在全面影响，各个参数存在较强的耦合关系，在工程设计时应权衡聚光特性带来的积极和消极影响。聚光太阳电池短路电流密度与聚光比成正比；低聚光比条件下，填充因子、转换效率基本不受聚光比影响；最大输出功率、开路电压随聚光比的增大而增大。聚光太阳电池工作温度升高对开路电压、转换效率和输出功率有不利影响，电池片散热设计是影响聚光电池性能的关键因素，应采用高导热率基板等散热措施以降低电池工作温度。建议聚光比为9~15，即可体现聚光优势，显著降低电池片使用量，又不苛求聚光透镜展开精度，从而降低工程研制难度。