Modeling and control of doubly fed induction generator for wind power

With increased penetration of wind power into the electrical grid, Doubly Fed Induction Generator (DFIG) for wind turbines are largely deployed due to their variable speed feature and hence influencing system dynamics. This paper presents the modeling and control of DFIG in details, where the stator is connected directly to a stiff grid and the rotor is connected to the grid through bidirectional back-to-back AC-DC-AC converter. The proposed model is the only complete detailed Simulink model which does not use the Semi-Power System toolbox and will be suitable to be operated in both sub-synchronous and super-synchronous mode of operation. A new vector control strategy based on the rotor flux oriented vector control has been proposed in this paper. the new vector control strategy is compared with the stator flux oriented vector control which is commonly used to control the DFIG. The two indirect vector control strategies based on the stator flux estimation, and rotor flux estimation have been applied to the rotor side converter (RSC) to control the stator active power produced by the generator. The complete system is modeled and simulated in the MATLAB/ SIMULINK environment in such a way that it can be suited for modeling of all types of induction generator configurations.