Modified Swarm Firefly Algorithm Method for Directional Overcurrent Relay Coordination Problem

Computational intelligence method such as Nature Inspired Algorithms (NIA) or meta-heuristic algorithms based optimization methods known to be successful in coordination of directional overcurrent relay. It has also been reported that it outperformed the conventional approach. Due to its advantages, it has gained more popularity among the researchers. Some of the conventional optimization techniques such as linear programming method and non-linear programming method were proposed but these methods is time consuming and complex to achieve optimal solution. Thus, a search for better optimization technique to reduce computation burden has become urgency. This paper presents the implementation of Modified Swarm Firefly Algorithm (MSFA) in solving directional overcurrent relay coordination problem. The effect of population sizes were considered to investigate the performance of MSFA technique. The coordination of directional overcurrent relays is formulated as linear programming problem and the objective function is introduced to minimize the operating time of the primary relay. Operating time of the relay depends on time setting multiplier (TSM) which leads to no miscoordination between relay pairs. The proposed method have been applied and tested successfully on 8-Bus test system and 9-Bus test system. The results revealed that MSFA outperformed Particle Swarm Optimization (PSO) in terms of computation time.