الفهرس 
Distribution System SchemesOnly 14 pages are availabe for public view
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Abstract
This thesis investigates the optimal siting and sizing of distributed generation units (DGs) in loop distribution systems considering repairing fault periods (RFP). Taking the RFP is accomplished through two different methodologies. In the first methodology, the optimal allocation of DG is identified by involving the terms related to RFP in the optimization problem with those related to normal operating periods. Accordingly, a two-part objective function comprising energy losses reduction and voltage profile improvement is introduced. Total DG capacity, voltage level, transformer ratings and power flow limits are considered as constraints in the optimization problem. Genetic Algorithm (GA) technique is used as an optimization tool for solving the objective function. Comprehensive analysis is introduced to compare between considering and ignoring the RFPs. In the second methodology, the optimal siting and sizing of DGs are identified for the two cases individually, i.e. the Normal Operation Period (NOP) and RFPs. In this case, it is assumed that the DGs will be located according to the optimal results of the NOP. During RFPs, a switching strategy is applied to achieve the optimal, or quasi-optimal, allocation of DGs by disconnecting some of the DGs from their original locations and reconnecting them at new buses. The new allocations are chosen to achieve the optimal situations based on the optimal results of the RFPs. This necessitates installing connecting cables between the original and the new buses. DG capacities have to be selected to enable flexibility in the switching process by the reconnecting the required number of DGs. Two scenarios of switching process are proposed and the energy loss savings due to apply each scenario is evaluated. The previous methodologies are implemented on an actual 15-bus 11 kV loop distribution system. The results show a noticeable effect for taking repairing periods into account when defining the optimal locations of DG in ring distribution system. Also, the results show the economic feasibility that could