Evaluation and Control of Effective Factors in Power Oscillations Emission for Variable-Speed Wind Turbine with Doubly Fed Induction Generator

With increase of wind power penetrations into the power system, attention to power quality becomes an important issue. Important aspects of power quality are flicker and harmonics. There are numerous factors that affect on flicker emission and power oscillations of grid-connected wind turbines for example wind characteristics (mean wind speed, tower shadow and wind shear effects and type of used wind turbine) and the grid conditions (short circuit capacity ratio and grid impedance angle) and type of the maximum power point tracking. In the present paper, performances of two maximum power point tracking methods (TSR and OTC) in fluctuations emission are evaluated and fluctuations caused by the tower shadow are then reduced by adding filter when the best MPPT method and grid conditions are selected. All aerodynamic, mechanical and electrical aspects of a wind farm connected to the grid are modeled using FAST and MATLAB/SIMULINK. The simulation results are given and they show well the effectiveness of the method proposed for improvement of power fluctuations.