Empirical Wavelet Transform and Fano Equality Ratio Test-based Fault Detection Scheme for Inverter Dominated Autonomous Microgrid

Modern power systems must develop a suitable protection mechanism, in order to deal with the technical challenges associated with the integration of distributed generation (DG) into microgrid systems. Specifically, it was noticed that for inverter-dominated microgrid, when operates in autonomous mode, fault current exhibits very low magnitude due to inverter control and their low electromagnetic inertia, which makes the traditional protection techniques vulnerable. While addressing the aforementioned issues, a straightforward and fast protection method based on Empirical Wavelet Transform (EWT) and Fano equality ratio test-based statistical measurement is proposed in this article. To investigate the performance of the proposed scheme, a 14-bus looped microgrid test system containing PV and battery energy storage system is considered. Primarily, using EWT the multiresolution coefficient of fault current signals at both ends of the line is estimated, and then by implementing Fano equality ratio test the adequate threshold setting is set for the identification of fault. The modelling and simulation of the test microgrid system are carried out in PSCAD-EMTDC software, and the fault detection algorithm is formulated and executed in MATLAB R2022(a) which uses data obtained in PSCAD.