الفهرس 
Introduction to Blowout PreventerOnly 14 pages are availabe for public view
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Abstract
Energy storage systems cannot be considered energy sources but having the ability of storing and discharging energy. They have a vital rule in the reliability and power quality of power systems. There are several energy storage systems (e.g. compressed air storage, battery, supercapacitors, hydrogen storage and flywheels) which can be selected according to the application requirements.Nowadays flywheels are playing an important role in the energy storage fields. They can be used in electric power systems for vast array of applications such as frequency support, uninterruptible power supply, voltage sag mitigation, flexible AC transmission and power leveling; also they can be used in other applications such as in transportation and pulsed power applications. They can be employed with several renewable energy sources. A flywheel energy storage system consists of a flywheel, an electric machine and a power conversion system. This thesis concerns with energy storage systems used in power system applications as they will be surveyed focusing on flywheel energy storage systems as a main concern.The main concern of this thesis is the power control of flywheels as energy storage system employed with grid applications. A large-capacity low-speed flywheel energy storage system based on a squirrel cage induction machine has been promoted as a viable means of energy storage for power system applications such as grid frequency support/control, UPS applications, power conditioning, and voltage sag mitigation. Therefore, this thesis proposed a developed power control strategy based on artificial neural networks (ANN) to charge/discharge a flywheel induction machine storage system while maintaining controllable grid side power.The proposed controller is based on conventional field oriented control system supplemented by an ANN-based current decoupling network used to develop the required stator current components based on the required grid power level and the flywheel instantaneous speed. The study is extended to compare this proposed control strategy with the performance of the conventional instantaneous power control strategy using an additional outer control loop. While the later provides higher accuracy and good response, the former offers higher execution speed in calculations with lower control effort and tuning problems.The validity of the developed concept along with the effectiveness and viability of the control strategy is confirmed by computer simulation using MA TLAB/Simulink for a low voltage 2.2 kW induction machine. A comparison between both of control strategies are carried out verified with the simulation results. The modeling of the proposed induction machine is valid based on the synchronously rotating reference frame transformation. An experimental rig of a flywheel energy storage system is set up to investigate the comparison between both control strategies and ensure the validity of the proposed control system.