Research And Implementation Of Solar Mppt Charge Controller Based On Fuzzy Control

The unlimited use value has become the focus of world attention as the shortage of solarenergy. There is no breakthrough progress in solar charge technology. Not only is photovoltaicdevices conversion efficiency low, but also is the battery more expensive. It is very significantto research photovoltaic battery charge technology. This paper did a deep reseach for solarcharge technology. By enhancing photoelectric conversion efficiency of solar cells andprotecting the lead-acid accumulator as the basic design objects, and using PIC16F877 tointelligent control. The solar energy maximum power point tracking (MPPT) technology andstorage battery charging technology were researched and simulated in this paper. The solarenergy MPPT charging controller is made based on the fuzzy control. The main content are asfollows.1. The solar battery mathematical model and output characteristics were researched, andthe outside temperature and the influence to output characteristic for illumination intensitywere analysied in this paper. The photovoltaic battery simulation model was established afteranalysing the photovoltaic battery array mathematical model.2. This paper put forward a kind of MPPT basing on the fuzzy control by analysing manyMPPT controlling strategy in order to enhance photoelectric conversion efficiency of solarcells. Then, the simulation models were designed by P&O and the fuzzy control separately,and compared the two methods. Finally, the experimental results showed the feasibility offuzzy control MPPT.3. After deep researching for the storage battery characteristics, working principle andcharging method, it designed the safety control circuit by using Multi-Stage constant currentcharging technology. For example, protection for reverse polarity, over current, over voltageand EMI. It analysed and calculated for the system main parameters. The 12V storage batteryis charged by Buck circuit. On software side, programs was designed by fuzzy control MPPTand Multi-Stage constant current charging technology and every program was explained. Thecharging results indicated that, this system had a very good charging function and a very highuse ratio for solar cell plate.The research work is supported by the State Key Program of National Natural Science ofChina(Grant No. 60534040),National 863 Project(Grant No. 2007AA05Z244)andGuangdong key laboratory of clean energy technology.