Self-correction two-machine equivalent model for stability control of FACT system using real-time phasor measurements

A self-correction two-machine equivalent model for the stability control of a flexible AC transmission (FACT)-based transmission system is developed. Shaping of the self-correction two-machine equivalent model uses only the real-time phasor signals available from the synchronous phasor measurement units (PMUs). The errors between the proposed model and practical power system are corrected by real-time measurements. The adaptive and robust behaviours both get involved in this model. In addition, linearity approximation is not used in its development. The proposed model is appropriate for transient stability control. Via the self-correction two-machine equivalent model, this work successfully applies the direct feedback linearisation (DFL) technique to a multimachine interconnected power system for transient stability control. The parameters and model uncertainties are also considered in the proposed DFL controller. This approach is then successfully applied to a three-area six-machine test system that installed two thyristor-controlled switch capacitors (TCSCs) controllers. Simulation results indicate that the proposed model and DFL controller are effective and robust in stabilising the transient swings between interconnected systems under various system conditions and the occurrence of severe faults