Abstract Doubly fed induction generator (DFIG) is one of the main technologies employed in wind energy conversion systems (WECSs). The history of the development of this technology, its importance, and its singularities are pointed out. This chapter presents several representations used to model DFIG according to the main goal one has in sight. The most common strategy to control DFIG variables is discussed and the control loops are presented. Also, the back-to-back power electronic converter used in this kind of WECS and the other auxiliary power electronic devices are shown. Finally, a brief discussion about DFIG main issue, that is, the low-voltage ride-through is done, presenting the grid code requirements and the Crowbar solution to it.