الفهرس 
Chapter 1: INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Nowadays, due to the great need of heavy industrial application, renewable energy sources such as PV sources have met more attention in recent researches specially using Z source inverter (ZSI) to overcome the limitations and problems of the voltage source inverter (VSI) and current source inverter (CSI) such as the limited AC output voltage that is either greater or smaller than the DC input voltage.
In this thesis the optimization of fuzzy logic controller (FLC) gains using PSO is employed to enhance the dynamic response of a PV array connected to three-phase grid through ZSI. The simulation results compared with others obtained by using the traditional PI controller tuned using Ziglar-Nicholas and also with PSO. The controller of the studied system consist of three loops are MPPT, power regulator and current regulator. The controller aims to make the system stable from the grid, ensure that the inverter has the ability to flow the AC power to grid at unity PF and makes the solar system operating at the maximum power by varying the ST duty ratio.The grid current is controlled by regulating modulation index, the MPPT control is realized by providing the control for the shoot through (ST) ratio (The MPPT is determined using Incremental conductance (INC) method). So, the control schemes aimed to minimize the final error and improve the dynamic response of grid-connected PV system under various disturbances. This simulation is done by using the MATLAB-SIMULINK environment. These results were studied under various disturbances as irradiation change in view of weather conditions variation, three lines shorted to ground at the grid side and increasing the grid voltage by 20% (voltage swells). The simulation results of FLC_PSO achieve supplementary enhancement of the system stability over various operating conditions compared with PI_PSO control.