PV-Battery Series Inverter Architecture: A Solar Inverter for Seamless Battery Integration With Partial-Power DC–DC Optimizer.

This paper presents system architecture and control scheme of a photovoltaic (PV) string inverter allowing seamless battery integration with the dc-series integration method. The architecture uses the partial-power processing universal dc–dc optimizer to have flexible power control by regulating the T-node compensation current. The universal optimizer is configured with a dual active bridge dc–dc converter allowing bidirectional power flow and galvanic isolation. Three operation modes are proposed depending on the input sources connected. Based on the operation mode, the universal optimizer and a dc–ac inverter switch their control reference to deliver the maximum PV power and perform battery current control. The steady-state and transient operation of the closed-loop control scheme have been demonstrated through controller hardware-in-the-loop tests to verify feasibility and effectiveness of the PV-battery series inverter architecture. [ABSTRACT FROM AUTHOR]