الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Electrical transmission system includes not only transmission lines that run from power plants to load centers, but also from transmission line to another transmission line providing a redundant system that provides smooth flow of power as in case of transmission line which is taken out of service in one part of power grid, the power normally reroutes itself through other power lines to continue delivering power to the customer. AC transmission systems came to prominence because they enable transformation of power between generation, transmission and distribution functions to their most appropriate voltage levels. The electricity from many power plants is pooled in the transmission system and each distribution system draws from this pool. This networked system helps to achieve a high reliability for power delivery since any one power plant only constitutes a fraction of the power being delivered by the power grid to meet the instantaneous demand requirements. As technology advanced, transmission enabled connection of local generation and loads at successively higher voltages. High voltage transmission systems improve capacity and efficiency and enabled integration of ever larger generating plants that were built nearer to fuel, water resources and further from load centers. Transmission systems must be kept highly reliable to prevent blackouts and ensure robust energy markets and it must be designed to accommodate all installed generated capacity and at the same time it must be configured to operate under normal and various contingency operating conditions to ensure providing electricity service all the time.