Monitoring and analysis of power system components affecting overcurrent relay coordination

In terms of the reliability of relay coordination in Electricity Distribution Networks (EDN), the delay time of the opening contacts of Digital Overcurrent Protection Relays (DOCPR), the error rates of current transformers and the opening times of SF6gas circuit breakers are of great importance. For this reason, contact delays of protection relays, tripping time delays of breakers and turning ratio errors of current transformers must be tested periodically, and necessary maintenance and replacement must be carried out on equipment that makes faulty measurements. In this thesis study, real-time tests of different brands of DOCPR, different types of current transformers and different brands and models of SF6gas circuit breakers, which are widely used in EDN in Erzurum province, were carried out. After examining the effects of real-time test results on relay coordination, optimum overcurrent relay coordination was achieved by taking into account the delay time of the opening contacts of DOCPR and the opening time delay of SF6gas circuit breakers. In addition, the maximum fault current that the relays will encounter in possible 3-phase short circuit fault situations of each busbar have been determined by means of the Electrical Power System Analysis and Operation Software (ETAP Demo) in the power system model of EDN. Using this fault current data, the total operation time of the relays in operation was optimized with the help of optimization algorithms.Relay coordination of EDN is considered as a constrained optimization problem. Real-time test data was used in the defined relay coordination constraints of the EDN model. Later, the metaheuristic optimization algorithms Genetic Algorithm (GA), Antlion Optimization (ALO), Whale Optimization Algorithm (WOA), Salp Swarm Optimization (SSA), Circle Search Algorithm (CSA) and Honey Badger Algorithm (HBA) methods were used. As a result, the performances of the optimization algorithms used in obtaining the minimum total relay operation time were compared.