Fault tolerant control of wind turbines with simultaneous actuator and sensor faults using adaptive time delay control

Abstract

In this paper, a new Active Fault Tolerant Control (AFTC) is proposed using adaptive fractional-based Terminal Back-stepping Sliding Mode (TBSM) control strategy for pitch angle control of a variable speed wind turbine in the presence of actuator and sensor faults. In order to detect, isolate and accommodate the faults, Time Delay Estimation (TDE) is used as an online fault estimation algorithm. To eliminate the chattering of conventional sliding mode, supper twisting sliding mode algorithm is applied, which also ensures finite time convergence and high precision. Moreover, wind speed profiles are generated using TurbSim, and the controller is implemented on a simplified two-mass wind turbine model. To verify the validity of the proposed scheme, the simulations are also performed in FAST environment, and finally, the simulation results are presented which reveal the effectiveness of the proposed controller in the presence of faults, uncertainties and turbulent wind fields.