Design and optimization of proportional resonant controller for rotor current of a wind turbine driven DFIG

This paper proposes an improved current control scheme for the rotor-side converter of a doubly-fed induction generator (DFIG) wind power generation system. The control scheme consists of a proportional (P) controller and a harmonic resonant (R) regulator tuned at the grid frequency. Thus, the positive and negative sequence components of rotor current are fully regulated by the PR controller without involving the positive and negative sequence decomposition. The design and optimization of the proposed PR controller is emphasized and investigated. Finally, simulation studies are carried out on a 1.5 MW wind-turbine driven DFIG system under unbalanced grid voltage conditions. The validity and feasibility of the proposed current controller are confirmed from the simulated results.