Study On New Type Of Photoelectric Sunshine Recorder And Its Correction Method

Sunshine hours is the sum of the time when the direct solar irradiance reaches 120W/m~2.Measuring sunshine hours is of great significance to agriculture,forestry,photovoltaic industry,and weather forecast.The sunshine meter is usually used as a measure of sunshine hours.At this stage,the dark barrel sunlight meter commonly used by the domestic meteorological departments can no longer meet the requirements of high precision and intelligence.Based on the analysis of the advantages and disadvantages of various current daylight metering principles,this paper designs a photoelectric daylight meter based on the principle of total radiation measurement.Firstly,the principle of total radiation measurement in the sunshine hours measurement system is introduced.When the sun enters the sensor surface,the Fresnel reflection does not satisfy the requirement of the cosine theorem of the irradiance due to the Fresnel reflection,and the PTFE diffuser is designed.The incident system of the projectile effectively reduces the Fresnel reflection and corrects the cosine error.By selecting a suitable photoelectric sensor and designing a corresponding photoelectric conversion circuit,the collection and processing of the solar irradiance signal to the voltage signal are realized.Second,aiming at the problem of low intellectualization of sunshine meters,this paper designed a data analysis module based on STM32 controller to realize the function of measuring,judging and accumulating the sunshine hours.The sunshine hours measurement system consists of a memory module and a clock module.,communication module,temperature control module and other modules,to achieve the intelligent data acquisition and processing of photoelectric sunshine;for the current measurement of the sun is not high,this article analyzes the main measurement error of the total radiation type sunshine meter.Based on the source,a new correction method to reduce the decentration error and attenuation error was proposed,which greatly improved the measurement accuracy of sunshine hours.In the final text,the main performance indicators of the designed solar irradiance meter were verified.The experimental results show that the maximum monthly cumulative error of the designed photoelectric irradiance meter is less than 10%,and the average no-fault working time is more than 8000 hours,and the power consumption is less than the heating state.15W,power consumption is less than 2W in non-heating state,can work in temperature range of-40-60°C,humidity range of 0%-100%,and has certain protection ability against precipitation and dust,meeting the requirements of National Meteorological Bureau for photoelectric type The functional requirements of the sunshine meter.