Fault Tolerant Modular Differential Power Processing Converter for Photovoltaic Systems

This paper proposes a fault tolerant modular differential power processing (DPP) converter for photovoltaic (PV) systems under partial shading conditions. The proposed DPP converter can be derived by integrating panel-level and module-level DPP converters, reducing the total switch count, and achieving a simplified circuit. The modular design of the proposed converter allows PV systems to be flexibly scaled up without redesigning converters. Furthermore, series-resonant tanks in the proposed DPP converter exhibit constant-current–constant-voltage characteristics that realize the inherent fault tolerance against short-circuit and open-circuit fault of PV panels. The prototype for a 1.5-kW PV system consisting of two modules, each comprising four panels connected in series, was built and tested. In addition to the fault tolerance, the energy yield enhancement of 19.6% was experimentally demonstrated.