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Electric distribution networks play a crucial role in the overall reliability of power systems due to their proximity to end consumers an‎d their wide geographical coverage. In recent years, the increasing penetration of distributed generation has altered the operational behavior of distribution networks an‎d intensified the complexity of their operating conditions. At the same time, higher levels of automation an‎d the deployment of remotely controllable switching devices have facilitated faster an‎d more flexible changes in network configuration an‎d distribution system reconfiguration. Under such circumstances, network topology changes can introduce significant challenges to protection systems, particularly in conventional overcurrent protection schemes with fixed settings. Topology modifications affect the direction an‎d magnitude of both load an‎d fault currents an‎d may also alter the relative roles of primary an‎d backup relays. Consequently, if appropriate decisions regarding protection settings are not taken, protection miscoordination an‎d increased load outages may occur. This thesis presents an adaptive overcurrent protection framework for reconfigurable distribution networks, with particular emphasis on the impacts of network topology changes. The proposed framework enables the eva‎luation an‎d selec‎tion between resetting relay parameters an‎d retaining their previous settings. In the proposed approach, network graph modeling is employed to identify the operating topology an‎d to extract relay sequences an‎d primary–backup relationships for each configuration. The protection coordination problem is then formulated as an optimization problem in which, in addition to time coordination constraints, both technical an‎d economic criteria—including relay operating times, relay resetting costs, fault occurrence probability, network reconfiguration duration, an‎d energy not supplied (ENS)—are incorporated. Genetic algorithm an‎d CHPSO are employed to assist in solving this optimization problem. To assess the effectiveness of the proposed method, simulations are conducted on the IEEE 34-bus an‎d 123-bus test systems, an‎d various network reconfiguration scenarios are examined. The results indicate that, by simultaneously considering technical an‎d economic aspects, the proposed framework can justify relay resetting in certain scenarios, while identifying the retention of previous settings as a more cost-effective option than others. These findings demonstrate the capability of the proposed framework to support informed decision-making in the design an‎d operation of protection systems for reconfigurable distribution networks.

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