الفهرس 
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Abstract
Wind energy conversion is the fastest-growing source of new electric generation in the world and it is expected to remain so for some time.
In Egypt, it has been decided that by the year 2020, about 20 % of electric power generated will be from renewable resources. Now we are producing almost 57% of the region’s total wind energy, we have already become the leading producer - ahead of Morocco, Iran and Tunisia. Furthermore, the Suez gulf area has one of the highest consistent wind speeds in the world at 10 m/s. Other important areas include the Western and Eastern deserts, in addition to the Red Sea coast along the Gulf of Aqaba.
The doubly fed induction generator (DFIG) with a power converter is a feasible, economical and highly controllable way to transform the mechanical energy from the variable speed rotor to the constant frequency electrical utility grid.
High performance variable speed drive systems using doubly fed induction generators have gained more and more popularity during the last decade due to the rapid development of power electronics and microprocessors.
This thesis presents an advanced study towards the enhancement of the performance of the doubly fed induction generator coupled to a variable speed wind turbine which is connected to the grid.
In this thesis, the mathematical model of the doubly fed induction machine in the d-q arbitrary reference frame is transformed into a stationary reference frame and the differential equations of the induction machine are derived. The closed loop transfer function describing the system is calculated. The analysis is performed by applying a step reference input then the behaviour of the system is studied without any type of control.
The rotor current is then controlled by applying a traditional control method which is the proportional plus integral plus derivative controller (PID controller) and the system performance is then studied.
The main contribution of this thesis is applying new control topologies to the doubly fed induction generator driven by variable speed wind turbine by choosing two types of artificial intelligence controllers. These are the artificial neural networks controller (ANN), and the fuzzy logic controller. In this study, the dynamic power system tools (MATLAB/SIMULINK) are used. The system is studied by using these control topologies and then the results are compared to the behaviour of the system using proportional plus integral plus derivative controller.