A Modified Switched-Capacitor Based Differential Power Processing Converter with Reduced Components for Substring-Level Photovoltaic Application

The mismatch of module characteristics due to partial shading can lead to serious power loss in series-connected photovoltaic (PV) systems. Various differential power processing (DPP) converters have been employed to improve the generated energy during partial shading conditions (PSCs). However, conventional DPP converters have poor scalability, low balancing efficiency and high cost for PV substring-level applications. This paper proposes a modified switched-capacitor converter (SCC)-based DPP converter for substring-level PV application. The proposed converter has reduced components and therefore has the advantages of compact size, low cost and simple control, which can be easily integrated into the junction box of PV panels. The proposed architecture inherits the benefits of conventional SCC-based DPP topologies, allowing the PV system to be easily extended without the usage of bulky transformers. Simulation results show that the proposed architecture can significantly enhance power generation in complicated PSCs. Compared with existing state-of-the-art SCC-based DPP converters, the proposed architecture can achieve comparable balancing performance with reduced components.