Simulation of Flicker Mitigation by Torque Control of Variable-Speed Wind Turbines with DFIG

Abstract: With increase of the Electricity demand the energy fulfilment is not possible with the help of conventional Fossil fuels. So, with the increase of wind power penetration into the grid, the power quality becomes an important issue. One important aspect of power quality is flicker since it could become a limiting factor for integrating wind turbines into weak grids, and even into relatively strong grids if the wind power penetration levels are high. 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 project 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 modelled using Matlab Simulink. Based on the presented model, power fluctuations caused by tower shadow effects can be analyzed and evaluated.

Keywords: SCR, DFIG, FLicker, WTG, IPC, Simulink,etc.