On-line and off-line fault detection techniques for inverter based islanded microgrid

To develop a stable and robust control that overcomes the challenges revealed by inverter based microgrid, it is very important to understand microgrid behavior when subjected to physical disturbances and associated power quality events. Microgrid faults leads to major power quality events and analysis of such faults will help in formulating a better control strategy. This article discusses an on-line and off-line technique using Park's Vector Trajectory (PVT) and Hilbert-Huang Transform (HHT) respectively to analyze fault transients in load current on occurrence of fault at the point of common coupling (PCC). From the analysis, it is observed that, detection of fault time and analysis of harmonic components can be performed using instantaneous frequency obtained from Hilbert-Spectrum of load current and PVT is useful in real-time detection of transients in load current.