A nonlinear TCSC control strategy for power system stability enhancement

In this paper, a nonlinear control scheme for the TCSC to dampen power oscillations and improve transient stability of a power system is presented. Based on a one-machine-infinite-bus system, a nonlinear mathematical model is established which is proven as an affine nonlinear system. With the help of the feedback linearization technique, the affine nonlinear model is exactly transferred to a linear model, and then, the control scheme is designed for the TCSC based on the global linearization, where the input signal uses local measurements only. The effectiveness and robustness of the proposed nonlinear control scheme are demonstrated with a one-machine test system, where the TCSC modeling and power system simulations are performed by using the NETOMAC program system. In comparison with a conventional control scheme, significant improvements of dynamical performance in the test power system are achieved by the proposed nonlinear control strategy for the TCSC.