Stability improvement in power systems with non-linear TCSC control strategies

In this paper, a non-linear control scheme for the TCSC (thyristor-controll ed series compensator) to dampen power oscillations and to improve the tran sient stability of power systems is presented. Based on an one-machine-infi nite-bus system, a non-linear mathematical model is established which is pr oven as an affine non-linear system. With the help of the feedback lineariz ation technique, the affine non-linear model is exactly transferred to a li near model, and then the control scheme is designed for the TCSC based on t he global linearization, where the input signal uses local measurements onl y. The effectiveness and robustness of the proposed non-linear control sche me are demonstrated with one-machine test system, where the TCSC modeling a nd power system simulations are performed by using the program system NETOM AC. In comparison with a conventional control scheme, significant improveme nts of dynamical performance in the test power system are achieved by the p roposed non-linear control strategy for the TCSC.