Research On Active Fault-Tolerant Control Of Wind Energy Conversion System

As a green and clean renewable energy,wind power is one of the important new energies to replace the traditional non-renewable energy.As countries around the world strive to make wind power generation an important part of their energy sustainable development system,the whole wind power generation industry is also facing great challenges.In practical engineering applications,wind power equipment is usually installed in remote mountains or away from the coast and other areas with harsh climate,and its internal structure is complex and diverse,belonging to a strong nonlinear system.Due to the long-term interference from the external environment and the influence of the uncertainty within the system,the internal component failure of the whole Wind Energy Conversion System(WECS)occurs frequently,which not only threatens the efficient,safe and stable operation of wind turbines,but also affects the extensive engineering process of the whole wind power industry.In this paper,the following research work is mainly done on the actuator and sensor failures with high frequency in the wind energy conversion system:Considering the parameter uncertainty of the system,the robust fault-tolerant control based on state estimation and fault reconstruction is studied for the actuator fault of the WECS.Firstly,the T-S fuzzy model is used to describe the system.Considering the uncertainty,unmeasurable variables and actuator fault of the system,the fuzzy scheduling fault tolerant controller(FRSFTC)is designed based on the observer fault reconstruction and the compensation control strategy.The controller and observer gain are obtained by solving Linear Matrix Inequality(LMI).According to the Taylor series and Lyapunov stability theory,the sufficient and necessary conditions of the closed-loop system stability under the condition of actuator failure are given,and the integrity of the system fault-tolerant control is realized.Finally,the wind energy conversion system is taken as a simulation example for analysis.The simulation results show that,considering the uncertainty of the system,when the actuator fault occurs in the system,the designed fuzzy scheduling fault-tolerant controller can achieve the maximum wind energy capture while ensuring the normal operation of the system.A fault-tolerant control strategy based on T-S fuzzy observer is proposed for sensor fault and uncertainty of the WECS.Firstly,considering the uncertainty of the system,the fault detection and isolation(FDI)method based on T-S fuzzy observer is designed by establishing the uncertain T-S model of the system.The residual is analyzed by comparing the state estimate value of the fuzzy observer output with the real sensor measurement value,and the state reconstruction of the output based on the normal sensor and observer is selected by the decision module and switcher.Then,a robust fuzzy controller is designed by using Parallel distributed compensation(PDC)to realize fault-tolerant control of sensor faults in uncertain nonlinear systems.Finally,Taylor series and Lyapunov stability theory are used to prove the stability of the closed-loop system.It can be seen from the simulation that when sensor failure occurs in the wind energy conversion system,the designed fault-tolerant control method can effectively reduce the shock and oscillation caused by the sensor fault,so that the safe and stable operation of the system under the fault can be guaranteed,the system's robustness can be improved.