Waveform Characteristic Analysis and Recognition of Short-circuit Fault in Grid-connected AC Microgrid

To detect and locate the short-circuit fault area quickly and accurately in the microgrid can reduce its impact on the large power grid under grid-connected mode. Therefore, it is necessary to study the waveform characteristics of short-circuit fault current in the microgrid under grid-connected mode. In this paper, a short-circuit fault simulation model is established in PSCAD. And the current information is monitored at the connection points between feeders and common bus of microgrid. Wavelet energy spectrum algorithm is used to analyze the detected current waveforms, and the characteristics of current waveforms are studied when various types of short-circuit faults occur. The simulation results show that the high-scale wavelet energy spectrum transform algorithm can identify and extract fault features, which provides a theoretical basis for the fast detection and location of short-circuit faults in microgrid in the future.