An MPC-based fault tolerant control of wind turbines in the presence of simultaneous sensor and actuator faults

In this paper, a fault-tolerant control structure is suggested in the full-load region of wind turbine systems to compensate for the effects of both actuator and sensor faults. This method is able to estimate all actual states of the system in finite time, and at the same time guarantee the fulfillment of all the parameter constraints. First, an MPC-based controller is designed in the full-load region to keep the output power in its rated value and hold the physical parameters in their allowed limitation. It is clear that any fault occurrence in the blade pitching actuators can make the output of the system away from its desired value. Furthermore, these types of faults can lead the system to instability and huge operating costs. To this aim, an additive control law based on a passive fault tolerant strategy is proposed to counteract the actuator faults. On the other hand, sensor faults and accurate estimation of the system's actual states in finite time are the other challenges of wind turbine control systems. In this regard, an observer based on terminal sliding mode is developed to cope with sensor faults and estimate all actual states within a finite duration. It is shown that incorporating all proposed approaches leads the closed-loop system to be robust with significant performance.