Modeling and Control of DFIG-based Variable Speed Wind Turbine

ABSTRACT The demand for electric energy is increasing day by day that has resulted in exploration of more and more alternate energy sources. Among the available alternate energy sources, wind energy, solar energy and fuel cells have drawn considerable attention. Further, all of these alternate energy sources are also of renewable nature. Among the mentioned alternate energy sources, wind power generation systems have been the most cost competitive alternative among all the environmentally clean and safe renewable energy sources in the world. Both fixed-speed squirrel-cage induction generator and variable speed double fed induction generator have been proposed in the literature for wind turbine generation technology. Since the direction and speed of winds may vary from location to location and time to time, the variable speed wind turbine technology offers inherent advantages over the fixed-speed one. The doubly fed induction-generator (DFIG) is used in tandem with the wind turbine to produce electric energy. The DFIG with the help of the two back to back converters: rotor side and grid side converters, is able to deal with wide variation of wind speed.