Whole-Range Nonlinear Large Disturbance Attenuation Controller Design for Turbo Generator Steam Valve Systems

For a class of strongly nonlinear reheat-type turbo generator steam valve control problem, a whole-range nonlinear adaptive large disturbance attenuation control scheme is investigated based on the Minimax and adaptive Backstepping method. The effect of unknown external disturbances on the rotor angle and the rotor speed of the generator are considered. The Minimax method is used to reduce effectively the conservativeness of the disturbance treatment, which is brought by the estimation of the upper bound of the disturbance and the inequality scaling. The purpose is to ensure the robustness and insensitivity to effects of large disturbances of the closed-loop system. By considering the effect of the short-circuit ground fault and the mechanical power of disturbances, an application of the single-machine infinite-bus system is researched. Simulation results show that the control scheme can effectively improve the dynamic process of the transient stability of the power system. Compared with the conventional nonlinear controller, the control scheme has more advantages for large disturbances, and the process of controller design is simple and intuitive.