Terminal Sliding Mode Valving Controller Based on COI Signal for Multi-machine Power Systems

This paper proposes terminal sliding mode controller of steam turbine-generator valve for multi-machine power system. The controller´s control objective is to make the system state tracking center of inertia (COI). Control laws are designed separately for each generator´s sub-system in order to achieve decoupling and practical controller. Considering the uncertain external disturbances, adaptive gain control is designed in order to estimate the upper bound of disturbances, so that the controller has strong robustness. According to Lyapunov theory, the stability of control system is proved. Four-machine system simulation results show that terminal sliding mode valve controller based on COI signal can damp power oscillation and improve the stability of interconnected power systems. At the same time, the COI signal within a certain range of delay does not produce significant effect on stability control effectiveness.