A Comparative Analysis of Optimal Relay Coordination For Different Network Configuration

An effective protection system should quickly isolate the faulty segment to avoid damage to the power system's healthy part. Directional overcurrent relays (DOCRs) are widely used as a protective device in medium and low voltage distribution systems. The DOCR operating time is a function of two parameters known as time multiplier setting (TMS) and plug setting (PS). The objective of a proper coordination scheme is to select these parameters so that the faulty section must be isolated in minimal time by corresponding primary-backup relay pairs while maintaining a minimum coordination time interval (CTI) between them. Hence, this work focuses on the optimization technique's performance in the determination of optimal relay settings to achieve proper coordination among all the relays. In this paper, a comparative analysis of relay coordination has been performed by using firefly algorithm (FA), simulated annealing (SA), charged system search algorithm (CSS), water cycle algorithm (WCA), vibrating particle search algorithm (VPSA), and grey wolf optimization (GWO) algorithm. To show the effectiveness of GWO technique, three different test cases are considered.