Static State Estimation of FACTS containing Synchronized Phasor Measurement Units

This paper proposes a practical approach to incorporate Flexible AC Transmission Systems (FACTS) devices and synchronized phasor measurements into a Weighted Least Squares (WLS) state estimation algorithm. The FACTS devices included in the estimator are the Thyristor Controlled Series Compensator (TCSC) and the Unified Power Flow Controller (UPFC). Phasor measurements of currents and voltages are directly appended to traditional measurements to estimate the equilibrium point of the power system. The proposed approach simultaneously upgrades the estimated values of the state variables of FACTS devices and the state variables of the rest of the electric network, for a unified solution in a single-frame of reference. Results are presented to demonstrate the effectiveness of the proposed approach to assess the estimation of the system state and to set the parameters of FACTS controllers for given control specifications.