| The solar simulator is a test and test device that can simulate the characteristics of solar radiation on the ground.The existing solar simulator can only simulate high uniformity solar radiation in a specific irradiation surface at a fixed working distance due to the influence of the imaging relationship of the optical system and the parameters of the concentrating system and the uniform system.However,it can not simulate solar radiation with high uniformity,variable working distance and irradiation area,which restricts the development and application of solar simulator.especially in the optical testing of special materials,such as material surface discoloration under sunlight.In order to improve the performance of solar simulator and expand its application fields,this paper studies and designs an optical system of divergent solar simulator with high radiation uniformity,variable working distance and radiation area.Based on the research and analysis of the application of non-imaging optical theory in the design of solar simulator,the composition,overall structure and working principle of the divergent solar simulator are discussed,and the optical system of the divergent solar simulator is emphatically studied and designed.An overall design scheme of optical system for a divergent solar simulator is proposed based on the technologies of annular focusing,imaging homogenization and cut-off filtering.By comparing and analyzing the existing light source,the xenon lamp is selected as the system light source;combined with the xenon lamp illuminating characteristics and the system optical path structure,a design scheme of ellipsoidal concentrating system based on the ring band theory is studied.A ellipsoidal concentrating system with large inclusive angle and high imaging ratio is optimized,and the energy utilization of the light source is improved.The homogenization principle of the existing homogenizing device is analyzed,and an optical system design scheme using optical integrator to achieve uniform light is studied.Combined with the characteristics of light source,system divergence angle,optical path imaging and Lach invariant,a homogenizing system based on imaging theory is optimized to improve the uniformity of irradiation.The modeling method of xenon lamp based on nested model is studied.Combined with other optical components,the overall modeling and simulation of the divergent solar simulator optical system is carried out.It is verified that the main technical indexes of the optical system meet the design requirements.The influence of the xenon lamp and the defocus of the integrator on the uniformity of the irradiation of the system lays a theoretical foundation for the adjustment of the optical system.A method for assembling and adjusting the optical system of the divergent solar simulator based on the self-aligned principle is proposed.By establishing the reference optical axis,the coaxial assembly of the steering plane mirror and the optical integrator is realized,and the uniformity of irradiation is improved.The main technical indicators of the optical system of the divergent solar simulator are tested.The results show that when the working distance is 6m,8m and 10 m,the irradiation surface is 1.2m,1.6m and 1.8m respectively,and the irradiation inhomogeneity is 3.33%,4.1% and 4.7% respectively,which meet the requirements of the technical indicators. |
