A new approach for mitigating blade passing effects and power quality improvement of grid-connected DFIG wind turbine

چکیده مقاله

Blade passing effects (BPEs) including tower shadow and wind shear cause 3P oscillations on mechanical and electrical active power profiles in a grid-connected doubly fed induction generator (DFIG) wind turbine. The basic aim of this paper was to present an effective method to mitigate the destructive problems caused by BPEs and to smooth the active power profile in DFIG, in addition to mitigate 3P oscillations on the voltage profile of the weak connected grid. The proposed approach was based on design and application of a band pass filter (BPF) to the external loop of DFIG active power control in the rotor side converter to remove 3P oscillations of the rotor reference current at mean wind speeds of 9–16 m/s. At high wind speeds, the proposed BPF is simultaneously used in the pitch angle control loop of DFIG to reduce 3p pulsations in the pitch angle profile. The simulation process is carried out at multiple wind speeds considering the new model of BPEs, which was derived to model these phenomena with a simple equation. The proposed model could be effective to analyze the DFIG performance, suitably via considering the adverse effects of tower shadow and wind shear, and to study the grid power quality problems. Simulation results are obtained for DFIG active power and grid RMS voltage profiles. These results validated the usefulness of the proposed method to improve the DFIG performance by smoothing the produced active power profile. Moreover, the periodic pulsations of the grid voltage profile are mitigated to enhance the grid power quality.