A hierarchical multiagent-based protection structure for meshed microgrids

This paper proposes a new protection structure to locate any type of faults in a meshed micro grid based on only measuring the current and voltage of the Distributed Generator (DG) that communicates with its neighboring DGs. In the first step, following a wavelet transform, a set of features are selected and fed to a Multiclass Support Vector Machine (MSVM) to detect occurrence and type of fault. Then, faulted zone-the area between two DGs that fault occurs between them- is determined thanks to two facts. First, one of the DG in two sides of the faulted zone endures the lowest voltage. Second, regarding fundamental frequency of 50 Hz, if this DG injects a harmonic of 300 Hz, the DG with the lowest voltage at 300 Hz is the next closest DG. Finally, based on the optimum features and these two DGs, a SVM is used to locate the faulted line. Simulation results show the effectiveness of the proposed method in a meshed micro grid.