الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 128 |  |  |
| | | from | 128 | | |
Abstract
Wind Energy is one of the most alternative solution for this challenge. Doubly Fed Induction Generator (DFIG) is considered as the most cost-effective generator for connecting wind power to the grid. It has advantages over other types of wind generators such as operating under variable wind speeds, moderate size of power electronics, and complete control of active and reactive power. It shares the advantages of synchronous generators (SGs) and inductive generators. Although DFIG wind turbines can be considered one of the most promising green renewable energy, they have many consequences on the system operation especially system stability when connected to a grid. This thesis proposes an algorithm that measures the impact of integrating DFIG wind turbines on system stability.Besides, the proposed algorithm is proposed to locate, size, and operate the DFIG wind power into the original system without violating stability limits. Small signal stability, voltage stability, frequency stability and transient stability are preciously assessed and utilized to achieve the proper system operation without any violation of stability limits. Small signal stability is used to prioritize available locations for DFIG. Then The voltage stability margin is used to identify the wind power penetration level at the pre-defined location(s). Next, approving the STATCom’s MVAr required for each penetration level to operate the system with wind power in a stable way using trial and error method.Afterward, the effect of load rejection on frequency stability is used to ensure the system is safely operated within the acceptable frequency limits to determine the primary frequency response. Finally, evaluating the impact of DFIG on transient stability using TSI (Transient Stability Index) and TRASI (Transient Rotor Angle Severity Index). The CCT (Critical Clearing Time) change of transmission lines is calculated after replacing synchronous generators with DFIGs.This thesis describes a new and detailed approach to determine the influence of replacing SGs by DFIG’s on different types of power system stability at the permissible locations within the acceptable penetration level. It also recommends the required MVAr to improve the voltage stability and the response of primary frequency control to enhance frequency stability and the critical clearing time for faulty transmission lines.The proposed algorithm is tested by applying the IEEE 39-bus test system using DIgSILENT Power Factory software. A comprehensive analysis has been implemented and results proved the effectiveness of the proposed algorithm.