Genetic Algorithm (GA) [7]-[9], Particle Swarm Algorithm (PSO) [10]-[11] among others are used to solve the issue of optimal coordination of overcurrent relays. The pickup value of an overcurrent relay must be set
between the maximum load current and the minimum fault current experienced by the relay. In high voltage and extra-high voltage networks, these parameters are often not well defined, for a safe selection of a pickup setting. For such cases, the distance relay furnishes excellent protection under all circumstances.