Modified modulation scheme of the buck-boost voltage source inverter for bidirectional power flow capability

Single-stage DC-AC power converters are gaining higher popularity due to their merits compared to the conventional two-stage DC-AC conversion systems. One of these converters is the buck-boost voltage source inverter. This converter has some merits over the other single stage DC-AC power converters in terms of passive component-count, overall gain ratio, and voltage stresses. This paper studies the possibility of using the buck-boost voltage source inverter as a bidirectional power converter, where it proposes a modification that should be applied to the conventional modulation schemes of the so-called buck-boost voltage source inverter to support the reverse power flow capability in it. The conventional and the proposed modulation schemes are simulated in a grid-connected mode using MATLAB/Simulink models, where the P+Resonant controller in the stationary reference frame is used. Finally a small scale prototype is used to verify the proposed modification.