Adaptive scheme protecting renewable‐dominated micro‐grids against usual topology‐change events

Abstract

Miscoordination and faulty operation are the two main protection challenges of renewable Distributed Generations (DGs) in Distribution Networks (DNs) and Micro-Grids (MGs). Although various approaches have already been presented in the literature, none of them has proposed a solution for simultaneous impact of DN/MG reconfigurations and DGs’ protection challenges. Topology-change being a usual method in decreasing power loss or voltage deviations, it would be preferable to have an online adaptive scheme considering all protection challenges together. Hence, the ordinary overcurrent relays using the IEC 61850 protocol capabilities are utilized in an algorithm capable of definitely assigning which relays are responsible for the on-going fault and which ones are not. That is, the algorithm is applied on a peer-mode multi-agent system (MAS) structure. First, the relay agents are classified into radial and loop Virtual Local Area Networks (VLANs). When a relay detects the fault, the MAS will find the responsible VLAN and instantly isolate other VLANs, including their agents. Next, the main and backup relays using the proposed communication map are assigned within the responsible VLAN. Last, a suitable protection algorithm is applied on the selected relays, according to direction of fault current.