Wind turbine sensor fault tolerant control via a multiple-model approach

This paper presents a new strategy for wind turbine fault tolerant control (FTC) to optimise the wind energy captured by a wind turbine operating at low wind speeds. The FTC strategy uses Takagi-Sugeno (T-S) fuzzy observers with state feedback control to maintain nominal wind turbine control without changes in both the fault and fault-free cases. The proposed strategy obviates the need for sensor fault residual evaluation and observer switching by using a fuzzy proportional multiple integral observer (PMIO) to mask i.e. `implicitly compensate' the sensor fault(s) from the controller input and provide good estimation over a wide range of sensor fault scenarios. The proposed FTC method is applied to a 5 MW offshore wind turbine (OWT) benchmark model.