Design Of Detection System Based On PV Power Station

With the rapid development of the PV industry, photovoltaic systems become more and more complex, the PV modules usually work outdoor, the work environment is severe, so people raise high requirements to the data collection PV array,data transmission and the condition monitoring. This article used the modular thinking to design a PV combiner though the analysis of the DC detection system and the theory study of the PV array output characteristics to realize the protection and real-time monitoring of the PV array system.It simplified system wiring and improve the reliability of the detection system.Firstly, though references, it compares the PV industry development at home and abroad, studies the research situation of PV detection system in different countries, for the actual demand for PV detection system, it proposes the value of DC side detection system.Secondly, though the study of grid PV system structure, it analysis the principles, structure, and classification of PV cells, based on the classical theory and classical mathematical equation, it analysis the output performance, compares the ambient temperature impact on its I-V.P-V curves, it designs the DC side detection system and the PV combine box structure.Thirdly, we design the wiring board of the combiner box,version control,communication module. Wiring board part,we choose the fast recovery diodes MUR8120and the high-current fuses according to the parameters to protect the system well.We design the filter circuit for the Hall sensor to improve the immunity.Detect and control system parts,we choose the Atmega128as the core of the data collection and detection according to the requirement of the low-power and multichannel.For the communication,we use the optical isolators to design the RS485practical circuit to enhance the stability of the signal transmission.According to the characteristics of the power that is flexible and small,we design a30W auxiliary power supply using single-ended flyback principle.Finally, the communication modules,the software system of the monitoring device programmed with C language is designed. And power failure protection has been added to the system aiming at the working environment of the convergence box.Experimental tests are carried out for each part of the system, the results show that the performance of the PV combine box is excellent, auxiliary power output is good, the collected test data is accurate, meeting the design demand.