| Meteorological solar radiation measuring instrument used as a meteorological monitoring equipment which can record solar irradiation energy a regional ground receives, has been widely applied in the global terrestrial radiation reference station network system. Along with the increasing level of China’s meteorological observation, a higher demand on the accuracy of the measurement of solar radiation measuring instruments has been put forward. For now it is imminent to develop a new meteorological solar radiation measuring instrument verification system, and it is an important and indispensable equipment to increase the accuracy data for global climate change and to make accurate prediction of meteorology. So, meteorological solar radiation measurement instruments’test sip is the problem to be resolved in the development and production of solar radiation measuring instruments. And the backwardness of our test equipment is the bottleneck restricting China’s development and production on this problem. This paper is based on the study of a variety of methods and solutions for solar radiation measurement instruments’test, in order to improve test precision and test efficiency. Finally develop a new multi-function meteorological solar radiation measuring instrument verification system, to solve the problems of the level of verification of solar radiation measuring instrument before it is put into use. The system can be used for high-grade indoor solar radiation measuring instrument’test, it is significance and value of our development and production of high-grade solar radiation measuring instruments.Based on the study of the theory of solar radiation and solar motion theory, use a solar simulator technology and multi-degree of freedom table, put forward a kind of overall design of a new multi-function weather solar radiation measuring instrument verification system, achieve the tests for sensitivity, nonlinearity, orientation response error, the cosine response error and tilt response errors of the parameters. Meteorological measuring instrument verification system is composed with solar simulator and the multi-dimensional table. Solar simulator provides uniform and stable simulated sunlight radiation for the verification system to, multi-dimensional table provides motion simulation of the various functions required of different sun angle for the verification system. These two integrate together to achieve the calibration of meteorological solar radiation measuring instrument system.In order to obtain uniform, stable and solar spectrum similar to the light radiation, design a coaxial quasi-direct solar simulator optical system consisted of short-arc xenon lamp, xenon lamp source, ellipsoidal condenser mirror, optical integrator, collimating lens, optical filters and optical attenuator. Design a full-spectrum filter to amend the xenon lamp spectrum to improve the spectral matching. In order to expand the scope of the regulation to the output radiation intensity, use the optical attenuator to compensate the defects affect of the xenon lamp low power for the radiation stability in the regulation. Use Lighttools optical light designing software simulating and analyzing the optical system, obtain the relationship between the output irradiation and the optical components’mutual position, these are the guidance for the optical system design of Solar simulator, installation and commission.Design the mechanical structure of the solar radiation measuring instrument verification system based on the test project and the optical system. Aim to the phenomenon of thermal centralization, determine using the double duct forced air cooling means to increase the heat exchange capacity of the inside and outside. Based on the thermal analysis of finite element for the key components, improve and optimize the structure reasonably. Through the thermal analysis of the condenser, find that, heat concentration located near the first focus leads to a necking deformation of the exit pupil of the condenser, so add cooling plate outside the mirror wall to improve the ability of heat output. Through the thermal analysis of the integrator and the field stop, find that, diaphragm necking deformation occurs along the axial direction, influencing collimation of the optical system. Considering heat dissipation as condition function, structure size of the objective function, optimize the structure of integrator. In order to better simulate the different elevation and azimuth angle of the sun, developed a multi-function table with four degrees of freedom movement consisted of tumbler institutions, pitch institutions, elevating institutions and rotating mechanism. Analyze stiffness of key components, and then develop the condition function and objective function to optimize the structure of the spindle and the arm.Do a theoretical analysis of the test system for the solar simulator and the multi-dimensional table, discover the reason influenced the spectral mismatch error and the uniformity error. Though the test on three solar simulator filter transmission curve, find that, as the coating thickness matching the transmission curve trough to move to longer wavelengths, scale down the thickness of each layer of titanium lanthanum mixture H4can amend semi-trough effectively. In order to improve the irradiation uniformity, use optical simulation analyzing the relationship between the irradiation uniformity and the consistency error of optical axis of the optical integrator. Analyze and calculate the kinematic error of the multi-dimensional table by error synthesis, then give the factors affecting the accuracy of the verification system. Thus, use multi-system dynamics theory determining the topology structure of the multi-dimensional table, establishing table generalized coordinate system, analyzing conversion between the various components, and then derive the characteristic matrix of the actual location and an ideal location of the platform space. Establish a model of geometric optical path error according to the law of rectilinear propagation of light, thus solve the eccentric error motion function of radiation center point to the location of the rotating center, draw a curve of error motion, and finally receive the maximum eccentric error.Test a lot to the measuring method based on the verification system, the data shows that the solar simulator is reliable, the indicators have reached the3A grade in the AM1.5standard. Workbench can complete each function, simulate different sun angles, the rotation precision is better than0.05°and can meet the technical requirements as well as test the meteorological solar radiation measuring instruments.In summary, the meteorological solar radiation measuring instrument verification system studied in this article has a high precision, a multi-function test and a high degree of automation, can test multiple parameters of solar radiation measuring instrument indoor, has a high practical value for China’s solar radiation measuring instrument quality assessment and production levels, particularly play an important role in the establishment of the base station network for ground radiation in the WMO World Climate Research Program. |
PDF Full Text Request