Single-phase Two-stage Photovoltaic Inverter System And Research Of Mppt Method

As the global energy crisis and environmental pollution problems havebecome more and more serious, Solar Power as a new kind of clean energy hasbecome a hotspot of the whole world. With the rapid development andutilization of solar energy, the photovoltaic (PV) power generation has becomean important research field.In the PV power generation system, one of the main research contents is toimprove its efficiency. The paper focuses on the grid-connected PV powerinverter system. Firstly, under the research achievements of existing PV powerinverter, single-phase double-stage PV inverter system is studied in detail andtwo level topological structure of DC-link and AC-link is determined. Next, bycomparing and analyzing the topological structure of the DC-DC, the push-pulltopological structure is adopted, and the push-pull circuit, the rectification filtercircuit and control driver circuit are interpreted respectively. Then, the controlidea of the maximum power point in the DC link is expounded in detail and therelevant circuit is designed. Finally, based on the AC-link analysis of thetopological structure, full bridge inverter circuit and control drive circuit aredesigned, the experimental results indicate the circuit designs are precise．In the basis of the present research achievements with solar energygenerating maximum power point tracking, this paper establishes a thesimulation model of photovoltaic cells according to the mathematical model ofthe solar cells, and analyzes the solar cell output characteristics. By the analysisand comparison of tracing the observation method of duty ratio perturbation ofpresent solar photovoltaic with the maximum power point, a duty ratioperturbation based on gray prediction is proposed and realized by the push-pullcircuit topology structure in the MATLAB environment. Simulation resultsverify the effectiveness of the algorithm.