为了实现直接辐射的太阳能量的耦合, 设计了一种分光谱辐射表入射系统。根据气象辐射理论对直接辐射表的尺寸进行约束, 利用几何光学理论设计导光锥, 使收光筒与光纤部分实现低损耗连接, 解决光纤与收光筒直接耦合时能量较弱的问题.通过在太阳模拟器下模拟的真实辐照度, 测试整个入射系统不同波长处的耦合效率, 以及不同跟踪角度误差下耦合效率的变化.理论分析表明, 导光锥和光纤两轴线的横向偏移是引起耦合损耗的主要因素.实验结果表明: 系统的耦合效率为66.24%, 在太阳跟踪器完全跟踪不到太阳直接辐射时, 耦合效率为12.8%, 反映了环日辐射和散射辐射水平.该系统可满足太阳直接辐射观测的入射系统要求.

A spectroradiometer incidence system was designed to realize the coupling of direct irradiance. In order to reduce energy loss between light-collecting barrel and fiber, and solve the problem of low energy level in direct coupling, the characteristic dimensions of the barrel were restrained, the lightcone parameters were calculated according to the geometrical optics theory. The coupling efficiency in different wavelengths and change of efficiency under different tracking angle errors were tested by solar simulator. The theory analyses indicate that axis’s lateral offset of lightcone and fiber is the main factor that caused coupling efficiency loss. Experimental results indicate that the coupling efficiency of the whole system is 66.24%, the efficiency is 12.8% when the sun tracker miss the sun completely, which reflects the level of circumsolar radiation and scattered radiation. The system can satisfy the requirements for the observation of direct solar irradiation.