Power Ramp-Rate Control for Differential Power Processing-based Distributed PV Systems

The grid support functionalities become mandatory in the revised standards for grid-connected renewable energy power systems, especially distributed photovoltaic (DPV) systems. However, the DPV systems in residential locations are scarcely invisible for system operators and easily affected by the environmental variations, especially mismatching induced by cloud passing. The differential power processing (DPP) is an effective architecture for eliminating the DPV system's module-level mismatching. However, the prior-art controls for DPP architecture are mainly focused on power maximization but missed grid support functionalities. To overcome this, a power ramp-rate control (PRRC) for PV-to-Battery DPP architecture is proposed in this paper, which guarantees the effectiveness of high ramp-rate fluctuation mitigation in mismatching DPV systems. Additionally, a post-ramp optimization strategy is proposed to maximize the conversion efficiency and constrain the power through into the battery according to the battery state of charge. Finally, simulation verification will be provided to prove the effectiveness of the proposed PRRC algorithm.