APPLYING THE NRBO ALGORITHM FOR CLUSTERING PROTECTION RELAY IN DISTRIBUTION NETWORKS WITH INTEGRATED DISTRIBUTED ENERGY RESOURCES

Abstract

This paper proposes a clustering and optimization approach for coordinating directional overcurrent relays in distribution networks integrated with distributed generation (DG). The Newton Raphson Based Optimization (NRBO) algorithm is employed to effectively group operating scenarios under the N-1 contingency, aiming to minimize the average operating time of relays across all scenarios. The algorithm is then applied to compute the optimal relay setting parameters for each Setting Group (SG), thereby enhancing relay protection performance while ensuring coordination constraints are met. The effectiveness of the proposed method is demonstrated on the IEEE 8-bus distribution system.  The results show that the relay operating time is reduced to 0.4773 seconds, achieving a 19.12% improvement compared to the pre-clustering configuration. This contributes to mitigating risks to both personnel and equipment during fault events.