الفهرس 
Chapter One : IntroductionOnly 14 pages are availabe for public view
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Abstract
Partial shading conditions (PSCs) decrease the total output power (TOP) from photovoltaic systems (PVSs) and causes multiple maximum power points (MPPs) on output characteristics because of the mismatching power losses (MPLs) among the photovoltaic (PV) modules. The partial shading pattern (PSP), the photovoltaic array topology (PVAT) and the shaded area are the main factors which affect the MPLs. The main aim of this thesis is to study and enhance the performance of a PVS under different PVATs and PSCs and reach to the most convenient topology.
At first, a tool for modeling and simulation of PV module using single diode model (SDM) is presented and tested. Then, the partial shading (PS) effects on multiple modules connected together in series as well as in parallel are discussed. The curves of current versus voltage (I-V) and power versus voltage (P-V) are plotted. And then the value of the change in energy produced due to PS is then determined and compared. The effects of addition a shaded module to a connected series and parallel modules are discussed.
It is concluded that the addition of a shaded module to a series connected modules decreases the TOP although even with the existence of the bypass diode. Where, the addition of a shaded module to a parallel connected modules increases the TOP. Also, the PV curve shape is similar to the non-shaded module and it has one peak.
Finally, this thesis has investigated the performance of series, parallel, series-parallel (2 x 3), series-parallel (3 x 2), total-cross-tied (2 x 3) and total-cross-tied (3 x 2) PVATs of a six PV modules which fixed as a 2 x 3 matrix. PVATs including series, parallel, series-parallel and total-cross-tied are studied. Row, column, narrow, wide, middle and random PSPs are considered at the different PVATs. The performance is measured according to the maximum output power,
MPLs, fill factor, efficiency, open circuit voltage (OCV) and short circuit current (SSC). The parameters and data specification of Suntech Power STD250-20/Wd PV module are used for the simulation based on MATLAB/Simulink software.
It is concluded that parallel topology gives the highest power but it provides a low voltage and high current and with the blocking diodes its power is less than the other topologies when measuring under the standard test conditions (STCs). The final important result states that: if the PSP which occurs a lot can be identified, the selection of the best topology is available from the different tables obtained in this research. But if the PSP which occurs a lot cannot be predicted or the system exposes to un predictable different patterns, the total-cross-tied (2 x 3) is recommended as it gives a reasonable voltage and current levels and its performance in average is good at STCs and under PSPs.