A New Communication-less Harmonic-based Protection Architecture for Meshed Microgrids

This paper presents a novel non-communication protection architecture based on utilizing the selected Distributed Generators (DGs) which provide high-frequency harmonics for harmonic-based overcurrent relays to detect and isolate three-phase faults in meshed microgrids. The most prominent features of this structure include limited number of DGs required to inject harmonics, no need for using centralized communication system, and the fault can be detected and located in all conditions such as load disconnection/connection and DG disconnection/connection. The optimum Time Dial Settings (TDSs) of these relays are obtained by solving a coordination problem with Particle Swarm Optimization (PSO) algorithm. Real-time results are produced using OPAL-RT to show the effectiveness of the proposed method for two different locations of faults in a meshed microgrid.