Robust control of a variable speed grid connected wind turbine for below rated wind speeds

The doubly fed induction generator (DFIG) is currently one of the most common back-to-back voltage sourced converter (VSC) of reduced rating, due to its connection to the rotor windings. This paper presents the design of a robust high order sliding mode controller for the regulation of active and reactive power. Furthermore, an optimal operation below rated speed is achieved by means of an appropriate maximum power tracking algorithm. An introduction of the subject is carried out. Then, the operating zones and control schemes are described. The simulation results show the effectiveness of the developed algorithms, with both smooth active and reactive power shapes, and optimum tracking of the available wind power.