An Efficient Direct Torque Control Strategy for a Doubly Fed Induction Generator (DFIG) in Wind Energy Conversation Systems

In this paper, the authors present an efficient direct torque control (DTC) for doubly fed induction generator (DFIG) in wind energy conversation systems (WECSs). The DFIGs are most employed in the WECSs because of their advantages, such as appropriate performance in variable wind speeds, control flexibility, and low cost. Many kinds of control techniques are proposed for the DFIG. One of the most simple and efficient control strategies with the fast-dynamic response is the DTC. The proposed control strategy is developed through a proportional-integral (PI) controller. This control strategy does not require any wind speed measurement and sensors. Moreover, in this strategy, torque ripple is a small amount; and then, the DTC can be used for rotor side converter (RSC). The new control strategy was analyzed and simulated in MATLAB/SIMULINK. The test system consists of a wind turbine model that drives a DFIG connected to the power grid through DC-link. It was also applied to a 2-pole, 0.2-KW DFIG. The obtained simulation results are illustrated pleasant and attractive advantages of the proposed control strategy, including simple control system structure, fast response, and easy integration of DFIG turbines with a large-scale power grid.