An advanced robust fault-tolerant tracking control for a doubly fed induction generator with actuator faults

Fault-tolerant controller (FTC) designs for doubly fed induction generators (DFIGs) with actuator faults have recently gained considerable attention due to their important role in maintaining the safety and reliability of DFIG-based wind turbines via configured redundancy. The objective of this paper is to propose a novel active fault-tolerant tracking control strategy for a DFIG subject to actuator faults. The proposed strategy consists of first designing a proportional integral observer (PIO) for simultaneous system states and fault estimation and then secondly the FTC, which depends on the estimated states and faults. The objective of such a controller is to drive the state of the system to track a reference state generated by a reference fault-free model (nominal system). In addition, the main results for stability are demonstrated through a quadratic Lyapunov function, formulated in terms of linear matrix inequalities (LMIs) in order to guarantee the stability of the whole closed-loop system and to reduce the actuator fault effects with noise attenuation. Furthermore, the gain matrices of the FTC and the PIO are computed by solving a set of LMIs using the YALMIP toolbox with the SeDuMi solver. Finally, the simulation results under constant and time-varying actuator faults are provided to show the effectiveness of the developed FTC scheme.