Communication-assisted Impedance-based Microgrid Protection Scheme

Development of efficient non-overcurrent based protection schemes is a prerequisite for significantly increasing microgrids renewable energy penetration. In this paper a novel communication-assisted impedance-based protection scheme is proposed. For the sake of protection design, we partition microgrids into protection zones based on the availability of fault interruption devices. The proposed scheme depends on monitoring impedance trajectories at different feeder relays to detect the occurrence of faults and utilizes directional elements to determine the direction of faults. Communications between feeder relays are utilized to exchange permissive and blocking signals in order to locate the fault and trip the least part of the microgrid to clear the fault. Simulation results are presented to demonstrate the effectiveness of the proposed scheme.