Fault-tolerant control of WECS subject to parametric uncertainties and sensor faults

In this paper we propose a multiobserver switching control strategy for robust Active Fault Tolerant Fuzzy Control (AFTFC) of variable-speed Wind Energy Conversion Systems (WECS) in the presence of wind variation, grid disturbance, parametric uncertainties and sensors faults. The "Takagi-Sugeno" (TS) fuzzy model with parametric uncertainties is adopted for modelling the nonlinear WECS and establishing fuzzy state observers. Sufficient conditions are derived for robust stabilization in the sense of Taylor series stability and are formulated in Linear Matrix Inequalities (LMIs). To illustrate the effectiveness of the proposed controllers, they are applied to WECS subjected to uncertain or unknown parameters and sensor faults.