Observer-based Adaptive Fuzzy Backstepping Control of Pitch Angle of Wind Turbine

In this paper, an adaptive fuzzy backstepping control method based on state observer is proposed for the individual pitch control problem of variable pitch wind turbines with state constraints and uncertainties. By designing a fuzzy state observer, the system state is estimated. The fuzzy logic system is used to approximate the unknown nonlinear term in the system. On the basis of backstepping control, dynamic surface control technology is introduced to solve the ‘complexity explosion’ phenomenon. By constructing the barrier Lyapunov function of the system, it is ensured that all the state variables of the system will not violate the constraints. Finally, the stability of the closed-loop system and the boundedness of all signals are proved by Lyapunov stability theory. The simulation results show that the proposed method can achieve effective tracking control of the pitch angle, which proves the effectiveness of the proposed method.