Study Of Control Technology For Solar Radiation Meter Calibration Systems

Solar radiation meters are used to measure the total energy of solar radiation reaching the earth’s surface,providing important analytical data for meteorological observation and disaster warning.In order to ensure the accuracy and reliability of the solar radiation meter observation data,the calibration system of solar radiation meter needs to be used before leaving the factory or in the process of use to calibrate the parameters of the radiation meter,the performance of the calibration system of solar radiation meter directly affects the calibration accuracy of the radiation meter.The calibration system of solar radiation meter consists of a xenon lamp solar simulator and a multidimensional turntable.The solar simulator simulates the radiation characteristics of the sun and the multidimensional bench simulates the movement of solar radiation on the ground.However,in the existing solar radiation meter calibration system,the position of the xenon lamp is adjusted by human experience,and the low adjustment accuracy affects the irradiation uniformity of the irradiating surface spot and the realism of the solar radiation characteristics simulation;the low positioning accuracy of the multidimensional turntable rotating arm mechanism affects the accuracy of some of the solar radiation meter parameter indicators.Based on the study of the solar radiation meter calibration parameter indicators,calibration methods and the composition and working principle of the calibration system,research is conducted to address the above issues.To improve the accuracy of xenon lamp position adjustment,the xenon lamp position control system is designed,including a multi-stage feedback control system and a xenon lamp position adjustment mechanism control system.The multi-stage feedback control system uses a photovoltaic cell to collect light spot information at the entrance of the optical integrator and the final irradiation surface,and designs the optical signal processing circuit and microprocessor program for data acquisition,calculation and transmission.The simulation results show that the accuracy of xenon lamp position adjustment is better than±0.05 mm for linear displacement and ±0.05° for angular displacement under the control of the control system.In order to improve the positioning accuracy of the rotating arm mechanism,the LADRC-based rotating arm mechanism position controller is designed and the positioner parameters are optimised using the CPSO algorithm.The results show that the positioning accuracy of the position controller with LADRC optimised control is improved by about94.12% and 75% compared to PI control and LADRC control respectively.A pilot study was carried out on the basis of an existing solar radiometer calibration system.The experimental results show that: after adjusting the xenon lamp position using the xenon lamp position control system,the irradiation unevenness of the irradiation surface of the calibration system is better than ±2%,the irradiation instability is better than±1% within Φ200mm and the irradiation unevenness is better than ±1% withinΦ100mm.The position controller of the rotating arm mechanism of the multi-dimensional turntable adopts LADRC optimized control strategy,which makes the positioning accuracy of the rotary arm mechanism better than PI control strategy and LADRC control strategy by about 78.31% and 54.3%,and the positioning accuracy is better than ±20″,meeting the main index requirements.The research on the control technology related to the solar radiation meter calibration system has improved the calibration accuracy and usage performance of the calibration system,which has certain practical significance to improve the performance of solar radiation meters and enhance the capability of meteorological observation in China.