Control of a grid-connected double-fed induction generator wind turbine

In this paper, three DTC schemes associated with space vector modulation (SVM) are proposed to control a doubly-fed induction machine using back-to-back configuration with three-level voltage source inverter VSI-NPC structure. These converters allow controlling the rotor voltage in magnitude and phase angle and can therefore be used for active and reactive power control. The control is especially designed to reduce the electromagnetic torque and rotor flux ripples of the classical DTC control using switching table. In addition, it´s convenient for high power drive and variable speed generator applications with restricted switching frequency. The detailed operation principle and simulation results of the proposed approaches are discussed.