The Research Of Two Stage Photovoltaic Grid-connected Inverter

World energy consumption and the worsening environmental pollution, renewable resources solar energy as part of the family, in recent years more and more attention by people. As a kind of clean energy, these problems can be solved by contributing significantly the use of renewable energy resources. With the development of solar energy technology, the using of solar energy from the light of the traditional to photovoltaic power generation, and it will certainly become the main form of the future and be rapidly developed.In the photovoltaic power system, the inverter is born to realize the light power power conversion of important devices and play an important role. Therefore, as a power of conversion of key equipment, its stability and conversion efficiency of electric power is particularly important for inverter and the control strategy of the research has the theory value and practical significance. This paper through studies in analyzing the traditional control method and put forward on the basis of traditional control strategy of the improved method.Firstly, analysis power and inverter of research situation at home and abroad; Secondly, it describes the application of the PV system. Many MPPT methods have been proposed and analyzed. In this paper, a variable step MPPT method is proposed for faster and more precise tracking process; Finally, combined with photovoltaic grid system topological structure analysis, the control strategy of through the OCC technology superior nonlinear. Then photovoltaic grid system can achieve high efficiency and stable operation. A Matlab/Simulink model was established as a double-stage PV system to analysis the performance of the proposed MPPT strategy and OCC technology. Simulation result in the last part proved that this MPPT and OCC technology method is practical with a better performance than the traditional strategies.