Double-stage grid-connected photovoltaic system with POSLL converter using PI resonant controller

Abstract

In this paper a proportional resonant (PR) controller for the single-phase double-stage grid-connected photovoltaic (PV) system is proposed. The proposed system consists of maximum power point tracker (MPPT) controller and PR controller. The current controller uses PR controller for the close-fitting regulation of grid current. The well-known perturbation and observation method (P&O) is used for MPPT. The proposed MPPT controller generates reference voltage of the PV panel and by comparing with its real value, switching command of DC-DC converter is generated. A positive output super lift Luo (POSLL) DC-DC converter is employed for the high voltage gain DC-DC conversion.