ENHANCEMENT OF EXTERNAL SYSTEM MODELING FOR STATE ESTIMATION

This paper addresses the issues of the external system modeling and th e detection of topology errors in the external system. A set of signif icant measurements and branches are identified in the external system based on their sensitivities on the tie-line flows. Any errors in the topology of the external system branches that are identified as signif icant are then detected. This is based on the degree of colinearity of the columns of the sensitivity matrix to the calculated normalized re siduals of the significant measurements in the external system. Simula tion results are presented using the IEEE 118 bus system as an example .