On circuital topologies and reconfiguration strategies for PV systems in partial shading conditions: A review

Photovoltaic (PV) power generation is heavily influenced by mismatching conditions, mainly caused by partial or full shading of an array portion. Such a non-uniform irradiation can lead to severe reductions in the power produced; some techniques, such as array reconfiguration or microconverters and microinverters technology are aimed at retrieving this power together with the use of Maximum Power Point (MPP) tracker algorithms, while others tend to mitigate the effects that power losses have on the PV system, i.e. overheating and aging. Solutions based on the use of bypass diodes and their re-adapted forms belong to this latter case. The complexity of the problem has shown the need of analyzing the role played by each one of the mentioned aspects; the focus of this paper is to give the reader a detailed review of the main solutions to PV arrays shading present in literature.