An FTC Approach to Wind Turbine Power Maximisation via T-S Fuzzy Modelling and Control

This paper presents a new strategy for offshore wind (OSW) turbine active sensor fault-tolerant control (FTC) to optimise the wind energy captured by a wind turbine operating at low wind speed via Takagi-Sugeno (T-S) multiple models with effective wind speed (EWS) estimation. The FTC strategy uses the proportional multiple integral observer (PMIO) as intermediate block between the system and the controller to provide (1) an estimation of the generator and/or rotor speed sensor(s) faults to compensate (hide) their effects from the T-S fuzzy dynamic output feedback controller (TSDOFC), and (2) robust estimation of the unknown aerodynamic torque component required to estimate the EWS. The Lyapunov stability condition and proof for the PMIO are derived and the TSDOFC stability with H∞ performance and D-stability constraints is formulated via a further Linear Matrix Inequality (LMI) problem. The strategy is illustrated using a non-linear benchmark system model of a wind turbine offered within a competition led by the companies Mathworks (USA) and KK-Electronic (Denmark).