High Impedance Fault Detection of Looped Microgrid based on Estimated Differential Energy using EMD-TKEO

The potential benefits of distributed generation (DG) integration into the distribution system (DS) are substantially undermined due to serious issues embarked with its protection during the unusual event of high impedance fault (HIF). Nonlinearly deterministic fault current characteristics with low fault current magnitude, nearly to the full load current, have thrown a challenge, while detecting HIF. This has further been augmented due to dissimilar contributions of fault current by different types of DGs, creating ambiguity for the overcurrent-based protection. In order to address this, in this work, a fast and simple HIF detection algorithm, based on Empirical Mode Decomposition (EMD) in conjugation with Teager-Kaiser Energy Operator (TKEO) is proposed for the looped microgrid system operating in grid-connected as well as in autonomous mode. Principally, it is established based on the extracted energy difference of current signals, which are obtained from successive processing of the retrieved current signals through EMD and TKEO. As this, does not rely on fault current magnitude; therefore, this method has essentially suppressed the difficulties that are associated with dynamic fault current of the microgrid.