Nonlinear robust control design for SSSC to improve damping oscillations and transient stability of power system

In this article, a nonlinear robust (NR) control is designed for static synchronous series compensator (SSSC) to improve transient stability and oscillation damping of power system. By taking the parameter deviations, external disturbances and unmodeled dynamics into account, the nonlinear dynamic model of SSSC can be changed into a Hamiltonian structure with the help of coordinate transformation. Based on the Hamiltonian structure of SSSC, a nonlinear robust control is designed for SSSC. Numerical simulation results on the two-area four-machine power system demonstrate the robustness and effectiveness of the proposed nonlinear robust control in comparison with the direct feedback linearization (FL) control. The study results show that the nonlinear robust control has better performance than the FL control.