Abstract: To address the generator speed fluctuation caused by failures of pitch angle sensors in wind turbines, we propose an active fault-tolerant control method based on a virtual sensor. The nonlinear model of wind turbines is converted into the linear parameter varying (LPV) model according to the LPV convex decomposition method. In addition, the structure of the virtual sensor is determined by the low rank condition of the output matrix. Simultaneously, the virtual sensor and the controller are obtained by solving linear matrix inequalities independently according to the principle of separation. The simulation results show that this method can compensate for the deviation and failure of a pitch angle sensor and can also maintain a stable generator speed and constant power output.