Low-Complexity Model Predictive Rotor Current Control of DFIG under Unbalanced Grid Condition

Abstract

During unbalanced grid condition, the electromagnetic torque of the doubly fed induction generator (DFIG)-based wind turbine will contain oscillation at twice of the grid frequency, which is harmful to the gearbox and shafting system of the turbine. Though various control strategies have been proposed to suppress the electromagnetic torque ripple, it is still a difficult issue to achieve satisfactory dynamic response and low complexity, simultaneously. To settle this problem, this paper puts forward a low-complexity model predictive direct rotor current control (LC-MPDRCC) strategy, with the control delay being compensated and the effect of the parameters changes being discussed in detail. Simulation studies verify the effectiveness and feasibility of the proposed method.