An interleaving double-switch Buck-Boost converter for PV grid-connected inverter

Characterized with noninverting and step-up/step-down conversion, the double-switch Buck-Boost converter is suit for the front stage of the two-stage PV grid-connected inverter. But, the large inductor is required in conventional control strategy, and the sophisticated control logic and difficult compensation technique for smooth transitions are included in combined control strategy. In order to reduce the inductor and simplify the control logic, an interleaving control strategy is proposed in this paper. The operation principle of the proposed control strategy as well as the characteristics is analyzed, and several terms under different control strategies are compared. Finally, the interleaving operation principle is verified by a 3kW two-stage PV grid-connected inverter prototype.