Integration of Battery Into Photovoltaic to Virtual Bus Parallel Differential Power Processing Architecture

This paper introduces a Parallel Differential Power Processing (PDPP) architecture for Photovoltaic (PV)/Battery applications. The PV to Virtual Bus (PV2VB) architecture enables the integration of a battery and manages its power while performing Maximum Power Point Tracking (MPPT) on the PV strings. In the proposed PV2VB PDPP architecture, the battery is positioned at the virtual bus, acting as the input for all string-level converters (SLCs). By selecting a lower voltage for the battery at the virtual bus compared to the PV string or the main bus voltages, component voltage ratings can be reduced. The architecture employs Dual Active Bridge converters connected to Bridgeless converters as SLCs to generate both positive and negative output voltages while providing isolation. These SLCs track the maximum power point (MPP) of each PV string, while the central converter manages battery charging and discharging. Experimental results confirm the performance and effectiveness of the proposed PV2VB PDPP architecture, achieving efficiencies between 95.5% and 99%.