Optimal coordination of overcurrent relays for microgrid operation using JAYA algorithm

Abstract

In modern microgrids, relay coordination is a very tedious task because of the variation in magnitude and direction of fault current. The change in fault current is diverse for inverter interfaced DGs (IIDGs) and synchronous-based DGs (SBDGs) The conventional relay protection scheme is found to be ineffective or non-functional in changing microgrid topologies with several protection issues. Therefore, optimum relay coordination is necessary for adequate protection of the microgrids. This paper proposed optimum coordination of directional overcurrent relays (DOCRs) with modified objective function using the JAYA algorithm in microgrid scenario. In addition to coordination time intervals (CTI), the proposed objective function also takes into account the miscoordination and insensibility factor. The JAYA method has the advantage of not requiring any algorithm-specific control parameters over traditional optimization strategies. The potency of the proposed method is tested on a 4 bus system and 13 bus radial distribution system and a comparison with other contemporary optimization techniques is approached. The outcomes gained with the proposed JAYA for relay coordination outperform other algorithms. The proposed approach ensures a superior convergence profile while avoiding the pitfalls of local minima and also helps to minimizes the objective function while retaining the CTI and accurately computing the relay operating time.