Four Port Solid State Transformer fed Dual Converter Topology for Utility Scale PV Farms

This paper presents a new system architecture for utility-scale PV farm is proposed. It uses four-port Solid-State Transformer (SST) for tight integration of ES with PV. The four-port SST generates two isolated Medium Voltage (MV) DC outputs that enable MV DC collection network, leading lower losses, and reduced balance of system cost. In addition, isolated MV DC network allows open end converter topology with simple MV power conversion to be used as the individual converter is only required to generate half of the AC voltage. The control scheme for the four-port SST and grid forming control of the open-end converter is described. The basic control functionalities are verified through simulation studies. The final manuscript will include results demonstrating other grid support functionalities and design details of the SST

Keywords: Solid-State Transformer, PV, rectifier