Mitigation of power fluctuation in variable-speed wind turbine with DFIG

With increase of wind power penetration into the power system, the power quality becomes an important issue and one of most important aspects of power quality is flicker. There are numerous of factors that affect flicker emission and power oscillations of grid-connected wind turbines including wind characteristics (e.g. turbulence intensity and tower shadow) and type of wind turbine and grid conditions (e.g. short circuit capacity (SCR) and grid impedance angle). In this paper, a torque control method is proposed by which power fluctuation is reduced using a series of band reject filters (BRFs). 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.