A new objective function for adaptive distance and directional over-current relays coordination

The complexity and importance of relay coordination problem are added by increasing interconnection and interpenetration of power networks. Online, adaptive, fast, and reliable re-coordination of relays are more needed to provide requirements of both clients and the new smart and fast-changing power network. In this paper, distance and directional over-current relays coordination problem is solved adaptively by using modified bees algorithm and changing the conventional objective function by using flexible coordination time intervals and pickup currents. The modification on the optimization algorithm has shown up to 50% improvement in efficiency that can be used in other optimization problems. 8, 14, and 30 bus sample networks were simulated to evaluate proposed method. The result of the optimization problem has shown a very good improvement compared with the methods that have been used in prior researches.