Nonlinear self-tuning control of a flexible AC transmission system

There is currently interest in using thyristor controlled series capacitors (TCSC) in transmission lines for the dual purpose of altering the steady-state power flow and enhancing system stability. Devices such as these come under the purview of flexible AC transmission systems (FACTS). We propose the use of nonlinear self-tuning control to enhance the stability of a multimachine power system using the TCSC, especially when faced with uncertainties in the transmission system parameters. A nonlinear generalized predictive criterion is used to derive the self-tuning controller. Simulation results illustrate the effectiveness of the proposed nonlinear self-tuning controller in simultaneously damping local-mode and inter-area oscillations