Scan-Dual-Mode Maximum Power Point Tracking Scheme for PV Systems under Partially Shaded Conditions

The growing use of photovoltaic (PV) systems in urban environment and on all types of buildings forces their optimisation in terms of energy harvesting, complexity and cost. Solutions for this compromising issue target source/charge adaptation problem (DC/DC converters) and controller’s command method (maximum power point tracking MPPT techniques). Besides, PV panels implementation has met another obstacle: shadows. The presence of non-uniform irradiation introduces additional MPPT difficulties such as having multiple local maximum power points (LMPPs). This paper proposes a novel MPPT technique for PV systems under partially shaded conditions. The algorithm controls a quadratic boost converter that presents the advantage of higher voltage gain ratio along with lower switching loss and voltage stress. First, a hybrid between an adaptive step P&O and an output voltage stabilization is developed as a new MPPT method for rapidly changing insolations. Then, a quick scan is included in a repetitive MPPT cycle to ensure tracking the global maximum (GMPP) among all local maxima. The architecture and the command algorithm boat the advantages of guaranteed effectiveness, high accuracy and robustness without additional advanced circuits or calculations. The efficiency and performance of the proposed method are proved for different shadow patterns considering all GMPP positions in MATLAB/Simulink environment.