الفهرس 
Introduction
thesis motivationOnly 14 pages are availabe for public view
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Abstract
The DG systems are one of the most important components of future smart distribution grids. This thesis investigates the modeling and performance of the main commercial types of power electronics interfaced DG systems (Microturbines, PV systems, Fuel cells, and DFIG WECS). The power electronics interface is essential to connect the DG systems to the electric network. Dynamic models of DG systems are developed in MATLAB/Simulink, and they are thoroughly tested and verified. Those models are then applied to developed case studies to test the proposed control strategies, which are designed based on the control objectives of the DG operation mode. For many techno-economical reasons, microturbines are the best choice for remotely located loads. Therefore, a proposed Voltage-frequency (V-f) controller of the power electronic converter is designed for autonomous operation. PV DG systems operate only in the utility-interactive mode. Therefore, a proposed Decoupled Voltage Oriented Current (DVOC) control is designed for the PV DG “virtual inertia” grid connection. Selection guidelines described in this thesis resulted in choosing the FC DG as the most appropriate option for dual active/reactive power operation. The DFIG is the favorable variable speed generator type due to certain economical and control benefits. The design and tuning of the back-to-back converter current controllers for grid connected operation, is developed based on the Internal Model Control (IMC) method. The LVRT capability is added to the DFIG WECS using a proposed active controlled crowbar protection circuit, which effectively protected the rotor circuit and kept synchronization and connection during voltage dips. An economic evaluation process is developed to choose the optimum DG and energy storage mix suitable for a typical example.