Control strategy using DC-link voltage for PV hybrid module system

In this paper, a control method for phase synchronous of each converter in photovoltaic (PV) hybrid module system (HMS) is proposed. A PV-HMS consists of a central inverter operated with a grid-line frequency and modularized converters installed backside of each PV module. In PV-HMS, the modularized converters has to operate with current-source converter using grid-line phase information because the central inverter is an unfolding bridge inverter which of switching frequency is equal to the grid-line. However, each modularized converter cannot get the grid-line phase information because these converters directly is not connected the grid-line. Therefore, this paper is proposed the control method for operation of each modularized converter through phase-lock-loop (PLL) DC-link voltage. The theoretical analysis of the proposed control method is verified by simulation results.