A novel H/sub /spl infin// based controller for wind turbine applications operating under unbalanced voltage conditions

Doubly-fed induction generator (DFIG) based wind turbines are highly susceptible to grid voltage imbalances. Normally the turbines are disconnected from the grid in the event of even moderate imbalances which contribute to poor utilization of the turbine. In this paper, a control strategy to use the grid-side converter in the rotor circuit of the DFIG to compensate for the grid voltage imbalance is presented. A robust H_infin controller is synthesized to minimize the adverse effects of the imbalances even while providing reactive power support to the grid. The control scheme is tested on a small-scale DFIG prototype and the results are presented