Adaptive terminal sliding mode power control of DFIG based wind energy conversion system for stability enhancement.

A novel adaptive terminal sliding mode instantaneous active and reactive power control for both the rotor-side as well as grid-side converters of the doubly fed induction generator (DFIG) based wind power extraction system is proposed in this paper using the abc frame of reference. This approach is independent of unmodeled dynamics of the phase-locked loops that reduces the nonlinearities in computing the control objective. The adaptive nature of the terminal sliding mode controller design offers a better and enhanced transient response as compared with some of the conventional methods for a wide range of disturbances such as switching faults, reference tracking and wind speed variation for both the sub-synchronous and synchronous modes of operation of the doubly fed induction generator subjected to lower and higher wind speeds. Moreover, a maximum power point tracking algorithm has been incorporated to compute the reference power of the stator of the DFIG, which is utilized in designing the control system for the rotor-side converter. Further extensive computer simulations have been carried out with the DFIG operating in a single machine or multimachine environment to validate the effectiveness of the proposed control. Also the robustness and stability of the proposed adaptive terminal sliding mode control is verified using the MATLAB/SIMULINK based DFIG model. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]