Submodule Level Configuration for PV System Performance Improvement under Partial Shading

Photovoltaic system performance highly depends on environmental conditions. Partial shading conditions (PSC) can significantly reduce the performance of the system due to the presence of multiple peaks in P-V or I-V characteristics and increase mismatch losses. Mismatch losses depend not only on the irradiance distribution over the modules in the PV array but also on the placement and interconnection used. Various techniques are proposed to reduce the mismatch losses such as full power processing (FPP), differential power processing (DPP), and array reconfiguration mostly employed and analysed. However, the cost and control complexity greatly increase with the system size for the first two techniques hence applied in small systems. For large-size systems, static PV array interconnection is economical and easy to implement. Different PV array interconnections such as series-parallel (SP), total-cross-tied (TCT), bridge linked (BL), and honeycomb (HC) and their combinations at the module level are proposed by various researchers. This paper aimed to propose PV array interconnections at the submodule level to enhance the system performance in a simple way. A novel TCT-TCT PV array interconnection is proposed and its performance under various partial shading conditions (PSC) is analysed and compared with standard SP and TCT Interconnection used at the module level.