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Partial shading (PS) is a major challenge faced by photovoltaic (PV) arrays invoking mismatch loss (ML). In this paper, the effect of PS on PV array performance is analyzed through experimental results and MATLAB simulation. The effect of PS on PV characteristics is investigated in two conditions. In condition one, modules are not coupled with bypass diodes, and in condition two modules are equipped with bypass diodes. New mathematical equations have been derived to calculate ML for condition one, and for condition two; locations of power peaks are identified in the power-voltage (P-V) curve. For both the conditions, theoretical results are verified through experimental results. From the obtained results it is observed that the error in loss calculation for condition one is less than 2% and for condition two, power peaks are being identified analytically with less than 3% error. To reduce the effect of PS on PV array, different configurations of the PV array were considered in the earlier literature. Among all, Total Cross Tied (TCT) PV array configuration is popularly used for its improved performance. To curtail the cost of TCT, two-hybrid array configurations such as TCT with bridge link (TCT+BL) and TCT with honey-comb (TCT+HC) are proposed here. Performances of different array configurations are analyzed considering various parameters such as global maximum power point (GMPP), currents and voltages at GMPP, the number of local peaks, shading losses, and mismatch losses. It is observed that proposed array configurations outshine in performance by reducing the amount of ML and the number of local peaks in the P-V graph, mainly for the stochastic shading patterns. [ABSTRACT FROM AUTHOR]

This paper deals with the selection of dc-dc converter and control variable required to track the maximum power of photovoltaic (PV) array, to optimize the utilization of solar power. To reduce the maintenance cost and to simplify the model, the battery has not been used in the proposed PV system mainly used for cooking and heating applications. Since the battery has not been used, selection of dc-dc converter is an important consideration of the PV system in standalone applications. In the proposed system converter is selected based on maximum power transfer theorem which is dependent on load resistance. Different load resistance is considered for maximum power point tracking (MPPT) with different converter topologies, and it has been observed that buck-boost converter is suitable for any load resistance connected in the PV system. An effort has been taken to suitably choosing the control variable which is the output signal of the maximum power point (MPP) tracker. Control variable which is dependent on inputs of MPP tracker is decided based on the stability of the system. Two MPP trackers are designed based on neural-network (NN) controller and perturb and observe (P&O) algorithm. The tracking capabilities of both NN controller and the P&O algorithm is compared with the variation of irradiation and found that tracking capability of NN controller is better than P&O method. The system is simulated using MATLAB/Simulink environment, and the results show that NN controller tracks MPP at a faster rate with reduced oscillation. [ABSTRACT FROM AUTHOR]