Design of back-stepping sliding mode excitation controller based on extended state observer

Considers the power system has nonlinear and uncertain disturbance, a nonlinear controller is designed combined with extended state observer (ESO), back-stepping and sliding mode. The nonlinear extended state observer is applied to estimate and compensate uncertainties in real time, thus improved both robustness and adaptability. The controller can hold the power system stability on conditions of Lyapunov function; a new sliding surface is designed. The whole control law can be obtained by applying the sliding mode control theory and the disturbance is attenuated. Simulation results show that proposed control method not only can improve the voltage and power angle stability greatly compared to the conventional control methods but also can restrain effectively unknown disturbance.