Evaluation of External Model Accuracy in Reactive EOPF Procedures

The use of reactive EOPF models was proposed for reactive OPF studies performed in control centers of interconnected systems. Reactive optimization procedures in interconnected systems are usually not coordinated since the problem under interest is intrinsically regional. In this context, the representation of external systems is indispensable. No matter what is done, however, the equivalent models introduce some inaccuracy into the OPF solutions. Certain fundamental issues involving accuracy and reliability of the modeling of external networks are still open to debate. This paper presents a study on the evaluation of three procedures that can be obtained from the EOPF model. The differences between the simple analysis of external-uncertainties influences and the validation of an external-network representation are evidenced here by comparing the optimization solutions of these procedures. The results were obtained with the IEEE-118 bus system