Abstract:The chaotic phenomenon of power system poses a great threat to the safe and stable operation of power grid, the chaos control of the fourth-order power system model with disturbance term is studied in this paper. Firstly, the influence of parameter changes on the dynamic behavior of the system was analyzed by using Lyapunov exponent spectrum and bifurcation diagram. Then, based on the system stability theory, a new backstepping sliding mode control method, which took the nonlinear smooth function as the sliding control law, was proposed to weaken the system vibration caused by the traditional sliding control law. Selecting different functions as control objective, the numerical simulation was performed by the MATLAB software. The results show that no matter how the objective function changes, and the power system can be quickly transformed from the chaotic state to the objective track by the controller, and effectively suppress the vibration.