Performance enhancement of PV arrays under partial shading conditions using SEPIC converter

Conventional techniques fail to guarantee successful tracking of the global maximum power point under partial-shading conditions. This results in significant reduction in the power generated as wells as the reliability of the photovoltaic energy production system. For the effective utilization of solar panel under partial shading condition, global maximum power point tracking method (GMPPT) is required. This paper discusses an improved perturb and observe technique for tracking global maximum power point of photovoltaic arrays that has better performance even under partial shading condition than the conventional tracking algorithms. Initially GMPP is located by adjusting the control signal and then the control moves to local MPP stage. For the present study, single ended primary inductance converter is used as the dc-dc interface for MPP Tracking. This is a buck-boost derived converter which is better suited for photovoltaic applications than conventional buck-boost converter. Solar panel has been modelled and partial shading effects are implemented. Simulation results showing the performance of modified algorithm are presented with the help of MATLAB/Simulink.