| Solar power is regarded as one of the most important energy in 21 Centry. It is a hotspot research in and abroad. Photovoltaic (PV) power generation has been paid much more attention and has became one of the new main streams of energy use. This thesis researches the control method of the single-phase two-stage grid-connected inverter, and designed 320W single-phase grid-connected inverter based on DSP.This thesis detailed analyses the theory of gird-connected system, confirms the main system topology and control precept. On the base of discussion of principle of operation, the dynamic performance of inverter is analyzed by the small signal of system model in open-loop and closed-loop. In order to reduce disadvantageous of perturbation of grid voltage, forward-feed compensation output is added to this system. This method is not only unchanged the characteristics but also improved stability.According to the strong non-linear of output characteristics of PV cells, the photovoltaic cells simulation model is established and the simulation which is the output characteristic of the solar battery under different temperature and irritation is completed. It is necessary for improving the efficiency of system to track maximum power point. Some traditional tracking control methods are analyzed and compared in this thesis. Based on this, an improved perturbation observation method is used to realize MPPT and achieve grid reference current amplitude control.Through the above study, it is built simulation model of grid-connected system using two-closed-loop added to forward-feed compensation control strategy. The simulation results shown that the control scheme proposal can implement. For the main technology parameters of 320W photovoltaic grid-connected inverter, the parameters of main circuit are designed. The hardware platform of the system is built and the result of experimental shows that the use of control strategies and method are feasible and effective.
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