Predictive control-based facts devices for power system transient stability improvement

It is generally acknowledged that transient stability of a power system is crucial to secure operation following a large disturbance such as a short-circuit fault. Drawing on the recent availability of, and advances in, high-speed flexible AC transmission systems (FACTS) devices, wide-area measurements (WAMs) and high-performance computer systems, the present paper has the objective of developing a real-time control methodology for enhancing and/or maintaining power system transient stability. The key contribution of the paper is that of deriving the control law based on the detailed dynamic model of the power system in the prevailing operating condition. Identification, in either online or off-line mode, of the model structure/ parameters is not required in the control methodology developed in the paper. Actual power system dynamic model of the form used in time-domain transient stability analysis combined with system dynamic response measurements is adopted for the control law derivation. High accuracy is, therefore achieved with the approach proposed. The effectiveness of the control methodology developed in the paper is illustrated by dynamic simulation using a test power system having a FACTS device of the thyristor-controller series capacitor (TCSC) type.