الفهرس 
Chapter 1: Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
Concerning the environmental issues, energy crisis and economic growth, the utilization of Renewable Energy Sources (RESs) toward high penetration in our community is seriously inevitable. For instance, the Ministry of Electricity and Renewable Energy of Egypt plans to increase the electric energy from RESs to cover 20% of the electricity demand by 2020 and 42% of the electricity demand by 2030. Thus, the popularity of RESs throughout the world will increase rapidly due to the three aforementioned issues. However, most of the RESs are connected to the power system through the power electronic interfaces called inverters/converters. The utilization of inverters/converters will significantly reduce the inertia of the power system (community). With the trend to increase the RESs in the power system, the overall inertia of the power system will significantly reduce and creates many stability problems in system frequency and voltage, leading to the weakening of the power system. This problem will widely affect people’s daily life and community by power interruption and in the worst case, may lead to power failure/blackout. The low system inertia issue is also one of the major restrictions to integrate RESs, which are clean, cheap, and sustainable to all communities. Therefore, the Renewable Power Systems (RPSs) have become more susceptible to the system insecure than traditional power systems due to reducing of the overall inertia of the power system that result from replacing the conventional generators e.g., Synchronous Generators (SGs) with RESs as well as decoupling of the RESs from the AC grid using power converters. Thus, maintaining the dynamic security of RPSs is the key challenge for integrating more RESs. Hence, this thesis proposes new frequency control techniques based on Superconducting Magnetic Energy Storage (SMES) system, virtual inertia control, and Virtual Synchronous Generator (VSG) for frequency stability enhancement of RPS considering high penetration level of RESs. Where, a suitable inertia control technique can be applied together with Energy Storage Systems (ESSs) to emulate additional inertia power to the community or power system, improving system inertia and eliminating the stability issues. Moreover, the proposed frequency control strategies are coordinated with digital over/under frequency protection for improvement the frequency stability and preservation of the dynamic security of RPSs because of the high integration level of the RESs. The effectiveness of the proposed coordination schemes is tested and verified through small and large scales of RPSs i.e., Microgrid (μG) and Egyptian Power System (EPS). The simulations results proved that RPSs with the proposed coordinated schemes will provide better stability and performance for today’s power system, and for those of the future, which are expected to integrate more and more RESs; thus, the proposed coordination schemes will ensure avoidance of power system instability and system collapse.