Performance Enhancement of Partially Shaded Photovoltaic Array Connected to a Microgrid by Optimal Reconfiguration Scheme

Abstract

newlineThe current research work deals with performance enhancement of Photovoltaic (PV) arrays under Partial Shading Conditions (PSC). Different shading patterns such as column shading, corner shading, row shading, diagonal shading, static PSC and dynamic PSC have been considered to realise the practical shading situations of PV arrays. The reversal of current flow in partially shaded PV modules leads to formation of hotspots and permanent failure of the module or entire array. To protect the PV arrays from thermal stress and hotspot effects, bypass diodes are integrated with each module in antiparallel to facilitate alternative pathway for surge current. To prevent circulating currents in the PV network, blocking diodes are used with each string of PV modules. newlineIn the prevailing research, different PV array configurations have been analytically studied and development of new reconfiguration schemes is proposed. Different interconnection schemes for partially shaded PV modules are studied in the present research work. The Novel Broken Diagonal Static (NBDS) reconfiguration scheme is also proposed for the optimal reconfiguration of a PV array under shaded conditions. In the current research work, a novel Su-Do-Ku Reconfigured Series Parallel Total Cross Tied (SR-SPTCT) scheme has also been demonstrated for a partially shaded PV array. These techniques are found to be superior to conventional and modified reconfiguration techniques in terms of reduced mismatching losses, improved fill factor, increased performance ratio and enhanced global maximum power. newlineThe present research also addresses the problem of extracting maximum power from shaded PV array. Due to high non-linearity in PV current and voltage during partial shading conditions, all the classical Maximum Power Point Tracking (MPPT) algorithms fail to efficiently track the Global Maximum Power Point (GMPP). An Artificial Neural Network based Dynamic Peak Tracking (ANNDPT) technique is proposed in this research work for maximum power point tracking in pa