Nonlinear robust controller design for thyristor controlled series compensation

The problem of transient stability for a single machine infinite bus system with thyristor controlled series compensation (TCSC) is addressed in this paper. The system does not need to be linearized, and the damping coefficient is measured inaccurately. A nonlinear robust controller and a parameter updating law are obtained simultaneously based on modified adaptive backstepping sliding mode control and Lyapunov methods. The closed-loop error system is guaranteed to be asymptotically stable. The simulation results show that rapid speed response and strong robustness can be obtained by the proposed method than the conventional adaptive backstepping and adaptive backstepping sliding mode control methods. The proposed method can be also be applied to other nonlinear systems with lower-triangular structure.