Optimal Coordination of DOCRs Considering Transient States of Fault Current in the Presence of Renewable and Non-Renewable DGs: A Review

Abstract

Renewable sources of energy (RSE) are intermittent and have a dynamic nature which in turn export these dynamics to the short circuit (SC) current resulting in the transient states to the SC current. So that, considering only the steady-state SC current during the coordination study of directional overcurrent relays (DOCRs) in networks with RSE and synchronous distributed generators (DGs) may make the protection system to be in risk, especially at the first moments after fault. Hence, the transient states of fault current should be considered during the study of DOCRs coordination. Moreover, connecting renewable and non-renewable DGs to the distributed networks leads to bidirectional power flow and fault level change which increase the complexity of the DOCRs coordination problem. Many review papers in the field of DOCRs coordination dependent on the steady-state fault current were presented, which is the motivation behind this manuscript to fill this research gap by introducing a review paper for optimal coordination of DOCRs considering the transient states of fault current with the exist of different types DGs. Moreover, comparing the pre-proposed techniques in this field of research and outlining the advantages and the dis-advantages of them. Furthermore, discussing the research directions of transient coordination based references.