Directional overcurrent relay coordination problem using Modified Swarm Firefly Algorithm considering the effect of population size

This paper presents the implementation of Modified Swarm Firefly Algorithm (MSFA) technique which considers the effect of population size in solving directional overcurrent relay coordination problem. The coordination of directional overcurrent relays is formulated as linear programming problem and the proposed technique is compared with those obtained using Particle Swarm Optimization (PSO). Implementation of the MSFA technique in minimizing the operating time of the relay which depends on the time setting multiplier has shown better results and avoiding miscoordination between each relay pairs. The simulation results on 8 bus test system demonstrated that the MSFA technique is capable in solving directional overcurrent relay coordination problem much better than PSO in terms of computation time.