الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Wind energy conversion has emerged as a viable alternative to meet the increased demand for energy resources in recent years. Wind farms interconnected to power system bring new challenges to power system operation. It is imperative to study the impact of wind power on utility grid operation. This thesis investigates the impact of wind power on utility grid operation through studying significant operation issues, such as reactive power injection, power flow analysis, voltage stability assessment and contingency analysis. In this thesis, a probabilistic voltage stability algorithm of WTGUs interconnected with the utility grid is developed via power flow analysis where these units are modeled by detecting the collapse point on the Q-V curves. In case of fixed speed wind turbines (FSWT), they can be considered as P-Q bus(es). While in case of variable speed wind turbines VSWT, they are modeled as P-V bus(es) and the reactive power generation inside the wind farm as a margin. The probabilistic nature of wind is considered by introducing the expected voltage stability margin as an index that combines both of the voltage stability and the wind distribution in one index. The proposed algorithms are implemented in Matlab environment and applied on a standard system, IEEE 26-Bus system and an Egyptian practical utility grid wind farm, Zafarana wind farm that is connected to a bus in the Canal Electricity Zone (34 bus system).Voltage stability margin (VSM), and expected voltage stability margin (EVSM) are calculated at each wind speed. The accumulation of the EVSM over a specific period can be considered as the system voltage stability margin which is a single value that can be compared with the voltage stability margin of an all-conventional power system.