Switched-Capacitor-Inductor-based Differential Power Converter for Solar PV Modules

Abstract

Energy harvesting from solar photovoltaic (PV) modules is affected by partial shading (contributes to mismatch issues), which in turn affects the entire system efficiency. Various power electronics converters have thus been investigated to address the mismatch issue due to partial shading, where the charges between PV submodules (typically, three submodules in a PV module) are redistributed. As a representative of the power electronic-based techniques, differential power processing (DPP) converters can improve the power extraction from the series-connected PV submodules. In this paper, a switched-capacitor-inductor (SCL)-based DPP converter is proposed to mitigate the mismatch effect for PV modules. The proposed converter only processes the differential power, enabling extraction of the maximum power from the PV module at a submodule level. The proposed topology is analyzed and compared with the traditional (Schottky) bypassing technique through simulations. Partial shading experiments are also performed for the traditional technique. A benchmarking with the prior-art DPP converters and experimental tests on the switched-inductor (SL)-based DPP topology are presented in this paper.