Fault Detection and Classification of Looped Microgrid based on EWT-TKEO

To procure thriving benefits of microgrid system, establishment of an appropriate protection system is mandated for the modern power systems. As a consequence of distributed generation (DG) penetration, the fault current becomes dynamic in nature, leading to make the conventional protection methods vulnerable. In order to resolve this, a simple and fast protection technique based on Empirical Wavelet Transform (EWT) in conjugation with Teager Kaiser Energy Operator (TKEO) has been proposed in this paper. For analysing the proposed method, a 14 bus generic looped microgrid structure containing both rotating type and inverter interfaced DG units is considered as a test system. This scheme estimates the multiresolution coefficient of symmetrical components of fault current signal using EWT, and then the adaptive threshold setting for detection and classification of fault is obtained by TKEO method for both grid-connected and autonomous mode of operation. This scheme is adaptive in nature as it can produce the threshold from the estimated Teager Kaiser Energy contained in the given signal. The test system is designed and simulated in PSCAD-EMTDC software, where the signal analysis part is performed in MATLAB.