Indirect dc-link voltage control of two-stage single-phase PV inverter

This paper presents a novel indirect DC-link voltage control scheme for the application of grid-tied two-stage single-phase photovoltaic conversion system. Unlike the traditional control method for grid-tied inverters where the DC-link voltage is always directly sensed to regulate the output current, the proposed scheme eliminates the DC-link voltage sensing unit but does not downgrade the inverter overall performance. The proposed scheme can be easily extended to control the multi-string configuration without any extra control complexity needed. Simulation verifications prove the effectiveness of the proposed control scheme.