Design Of A Thermopile Total Solar Radiation Sensor

Total solar radiation is an important measurement parameter in meteorological exploration, solar resource utilization and other fields. The total solar radiation sensor is an important ground meteorological observation instrument, and it is also an indispensable equipment for solar energy resource census and PV power plant operation monitoring. At present, the accuracy of foreign total solar radiation sensor is relatively high, but it is expensive.In order to design a low cost and high precision solar total radiation sensor, this paper proposes a total radiation sensor based on thermoelectric effect for the problem that the ambient temperature will affect the total radiation measurement accuracy.The sensor system consists of sensor probes, signal acquisition circuit, temperature compensation algorithm, embedded system and the host computer. A computational fluid dynamic method is utilized to analyze the heat transfer of the sensor probe. In the hardware aspect, this paper uses the low power consumption and cost-effective STM32 as the CPU. A high precision AD acquisition circuit is designed, which is measured by thermopile, PT100 temperature sensor. In order to simplify the hardware circuit and ensure the high accuracy of the measurement, the Levenberg-Marquardt algorithm is used to fit the thermopile temperature characteristics. This paper uses the Back-Propagation (BP) neural network to eliminate the total radiation measurement error caused by the ambient temperature.To facilitate the use of observers, this paper developed a supporting PC software based on the C #.The temperature compensation range of the sensor used in this system is -20??40?. The field test results show that the reading accuracy can reach 2.79%, and the full scale accuracy is 1.66%. The sensor may find potential applications in the field of meteorological detection, photovoltaic power station and so on.