Hybrid fuzzy sliding mode control of a doubly-fed induction generator speed in wind turbines

The aim of this paper is hybrid fuzzy sliding mode control of a Doubly Fed Induction Generator (DFIG) in the form of a wind turbine. This type of control is introduced to avoid the major disadvantage of variable structure systems, namely the chattering phenomenon. Variable structure ensures the high dynamic of convergence and robustness towards parametric variations and disturbances. Fuzzy control is introduced here in order to remove residual vibrations in high frequencies. That approach is used to control the mechanical speed and the reactive power exchanged between the stator circuit and the grid. Those variables are decoupled through vector control. The feasibility of this work is proven by mathematical and simulation models based on MATLAB.