Comparison of Phasor Estimation Techniques for AC Microgrid Protection

Microgrid(MG) provides numerous advantages such as reduced transmission losses, low carbon emission, improved system reliability. However, for the proper functioning of the MG, it should be protected from different fault conditions. Detection of fault conditions in MGs is challenging because the fault current magnitude varies in various modes of microgrid operations, types of DGs used, ratings of DGs, and bidirectional fault current flow. This article presents a signal processing-based technique to determine the faults in the microgrids and state-of-the-art latest research on microgrid fault detection. This paper analyzes different phasor estimation techniques, for instance, Discrete Fourier Transform Technique (DFT), Kalman Filtering Technique (KFT), and Least Square Technique(LST) for microgrid fault detection. The pros and cons of DFT, KFT, and LST are analyzed. The microgrid with various types of DGs is simulated using RTDS/RSCAD (Real-time digital simulator), and the Least Square Technique can effectively detect different fault conditions in the microgrid.