Monitoring Of Output Characteristics Of Solar Cell And Environment

The solar energy is a kind of very promising clean new energy. Today traditionalfossil fuels such as oil and coal are declining and environmental pollution andgreenhouse effect are increasingly serious. The new energy attracted the attention ofmore people. Solar power is the best in new energy. With its safe, clean, low failurerate, less pollution, and many other advantages, solar power are being more and moreattention both at home and abroad. Hunan university30k W photovoltaic solarintegration project is one of major projects funded by the nation.This thesis researchtopic belongs to one part of it.There will be a hot spot phenomenon due to shade, aging when solar cellsworking, seriously impacting on the solar cells output power. In order to understandthe impact of environment on solar energy, more efficient use of solar energy, it’sneeded to learn more about output characteristics of the solar cells and variousparameters of environment the solar cells in. The main job of this paper concludes twoaspects: firstly, to get the output characteristic curve of solar cells; Secondly, theparameters for the environment solar cells in, including temperature, humidity, andirradiance. NMOSFETs could be equivalent to a resistance. This paper takes aNMOSFET for a simulated load of solar cell with this feature. The grid voltage ofNMOSFET is controlled by a CC2530wireless MCU. CC2530is programmed by Clanguage. On one hand, CC2530wireless MCU to adjust the voltage of NMOS gate,making it work in a different degree of conduction and different working point forsolar cells; On the other hand, CC2530wireless MCU get the output voltage andcurrent of the solar cells from the voltage and current sampling circuit. A ADCintegrated in CC2530convert the analog signal to digital signal. CC2530updatas databy a wireless personal area network builded by themselves. The PC terminal softwarewill draw the output characteristic curve of solar cells, after getting data. A commontemperature sensor DS18B20is designed for environment temperature measurement,which integrated the highest12bits digital output. A capacitance sensor HS1101and555timer is designed for humidity measurement. A timer integrated in CC2530captures the output frequency of the555timer. Environment humidity value iscalculated by interpolation. Irradiance is the most important factor in influence the solar cell output power. This paper takes PMA1144for irradiation intensity meter,which convert irradiation to electrical signals with linear relation.And then aoperational amplifier enlarge the signal and to the voltage range that is suitable forinput of ADC in CC2530chipe. ADC convert s it to digital. For abnormal components,the paper proposes an algorithm of target positioning for the distributed sensornetwork with high precision, which could quickly positioning abnormal component s.Test shows that the design of the solar cell output curve of the acquisition, theenvironmental parameter acquisition, stable, effective and meet the designrequirements.