A creative approach for the protection coordination of microgrids considering parallel events via the pyramidal grouping technique

Over the last few years, numerous research findings have emerged that incorporate the single-event or islanded case when designing models for protection coordination of microgrids via directional overcurrent relays (DOCRs). Nevertheless, the dimensions and complexity of this issue can be significantly increased by the parallel events. This paper introduces an innovative methodology for reducing the scope of parallel events. The pyramidal grouping technique is employed to organize the selected events into separate groups. In brief, the problem's choice parameters are identified by an innovative mixed algorithm, known as the sequential quadratic, Quasi-Newton, and linear programming method (SQ-QN-LP). It is noteworthy that the SHARIAT feeder, which serves as a real-world grid, and the IEEE 399-bus network have been configured without any signs of miscoordination. In comparison to other comparable methodologies, such as SQ, QN, SQ-LP, QN-LP, and SQ-QN, the actualization of SQ-QN-LP decreases the relay's time to function by approximately 75% to 22% in the mentioned networks.