Solving Directional Overcurrent Relays Coordination problem using Different Multi-Objective Optimization algorithms with Fuzzy Logic Decision-Making Tool

The most complex structure that has developed over the last decade is the network of the electrical system. Protective equipment's main function is to maintain network reliability. Directional overcurrent relays (DOCRs) are generally used in power systems. The target of coordination between DOCRs is to maintain unfaulty parts in service and isolate faulty sections only. In this paper different multi-objective techniques are presented to solve the coordination problem. The first objective function suggested decreasing the total operating time for DOCRs. The second function is suggested to minimize the delay between primary/ backup DOCRs. The feasibility of the proposed algorithms is tested using different systems.