LOCAL OPTIMAL COORDINATION BASED ADAPTIVE COORDINATION

This paper presents the development of an adaptive coordination scheme for the coordination of directional overcurrent relays for large inte rconnected power systems, using the concept of local optimal coordinat ion under the changed system conditions. In response to a structural c hange or an operational change in the power system, the developed adap tive local optimal coordination algorithm automatically identifies the local disturbed region and re-coordinates only the settings of the re lays which fall inside this identified local region in an on-line mann er. The scheme developed is applied to the IEEE 57-bus test power tran smission system. The results are validated through a full system coord ination study and the usefulness of the reported algorithm is demonstr ated.