Simulation research on photovoltaic grid-connected system

With the rapid development of new energy resources, more and more renewable energy is fed into the grid through grid-connected inverter. A simulation model of PV grid-connected system is built in MATLAB/Simulink, and the output characteristics of the PV cells are analyzed. The P&O method (Perturbation and Observation) is used to achieve MPPT (Maximum Power Point Tracking). A double-closed-loop control strategy including a voltage outer loop and a current inner loop in grid-connected operation and a V/f control strategy in the island operation are proposed. The simulation results show that the system can achieve MPPT of PV cells, which can also realize stable operation. The control strategies proposed in this paper have some reference significance to the actual PV system design.