State estimation of systems with embedded FACTS devices

This paper is concerned about the state estimation of systems, which contain flexible ac transmission systems (FACTS) devices. State estimation formulation is modified in order to incorporate the detailed models of the unified power flow controllers (UPFC). This necessitates the use of equality and inequality constraints that account for the limits associated with the device operation and ratings. Furthermore, in addition to its use as an estimator, the developed program can also be used to determine the required settings for the controller parameters for a given operating condition. Simulations on small and medium sized power systems are presented to demonstrate the use of the developed program both as a state estimator and for setting the parameters of power flow controllers.