A novel DC grid connected DFIG system with active power filter based on predictive current control

The paper presents a novel DC grid connection technique for wind power generation system based on the double fed induction generator (DFIG), in which a diode bridge rectifier is directly connected to the stator side of DFIG to connect DC grid. The direct voltage control is applied for the DFIG system to achieve the sinusoidal stator voltage. In order to eliminate the harmonic currents produced by the diode rectifier, an active power filter is built between DFIG stator and the diode bridge, in which the predictive current control is applied to remove the control delay caused by computation and sampling. The availability of the proposed system and control strategy is validated by the simulation results on a 1.5-MW DFIG-based DC grid connection system.