Nonlinear PI predictive control design for Thyristor Controlled Series Compensator

This paper presents a new control design for the Thyristor Controlled Series Compensator (TCSC) based on Nonlinear PI Predictive Control scheme (NPIPC) to improve the transient and dynamic performance of power system. The control scheme considers uncertainty of power system. The stability of the closed loop system under this nonlinear controller is guaranteed by the control law which includes a predictive part that can predict the future of the system´s output caused by the system dynamics. A local control approach is also applied so that all input variables can be obtained locally and easily. To validate the proposed control scheme, we perform simulations on single- machines double line infinite bus power system equipped with TCSC using PSCAD/EMTDC software package under steady- state and dynamic stability. The simulation results show the superiority and robustness of the proposed control compared to conventional control systems. The results also show that the proposed TCSC controller is effective in damping low frequency oscillations resulting from small disturbances condition like decrease in mechanical power input.