A direct torque and reactive power control approach for doubly fed induction generator in wind turbine applications

This paper focuses on a new direct torque and reactive power control approach for doubly fed induction generators for wind turbines. In order to design the rotor side controller and study the transient behavior, equations which directly describe the dynamics of the torque and reactive power in a doubly fed induction generator are proposed in this paper. Relying on these equations, controllers using internal model control are discussed to guarantee the transient behaviors of the torque and reactive power. These controllers are designed based on stator flux orientation but can also be implemented in a stationary reference frame, where the full order model of the doubly fed induction generator is considered. The stability and robustness of the proposed control approach are demonstrated in the paper. The proposed control approach is implemented and validated in Matlab/Simulink. The simulation results demonstrate different transient dynamics with different transient compensations and the robustness of the proposed direct control approach.