Research on Control Strategy of PV MPPT and Grid-connected Single Phase converter based on Two Stage Topology

This paper studied the control strategy of single-phase two-stage grid-connected photovoltaic generation system. The two-stage topology includes the boost converter and single phase inverter. The function of maximum power point tracking (MPPT) is achieved in the boost circuit by IC (Increment Conductance) method. The inverter circuit adopted the double-closed loop control, a DC voltage outer loop control for power balance with PI correction and an AC current inner loop control for feedback designed to ensure the current quality and stabilize the DC voltage. The inner loop used the novel quasi-Proportional-Resonant (PR) controller, which has a better steady tracking characteristics and stronger anti-interference ability to the disturbance. Finally, a simulation system is built with Matlab/Simulink in this paper to verify the validity of the MPPT algorithm and the quasi-PR control strategy.