I&I stabilization based novel nonlinear adaptive TCSC control algorithm for improving transient stability

This paper presents the transient stability enhancement of power transmission system by adopting immersion and invariant (I&I) stabilization and sliding-mode observer in designing Thyrister Controlled Series Compensation (TCSC) adaptive controller. In designing the TCSC controller, a deduced-order target system is first defined and the dynamics of the controlled system will be “immersed” into it based on I&I stabilization theory. The proposed TCSC controller is then made adaptive by designing adaptive update laws for the unmeasurable damping coefficient and mechanical power based on adaptive sliding-mode observer to identify the two uncertain parameters of the controlled system. The simulation results demonstrate the effectiveness of the proposed novel nonlinear adaptive TCSC controller.