A new direct torque control of doubly fed induction generator for wind power generation

This paper presents a new direct torque control (DTC) method for doubly-fed induction generator (DFIG) based wind power generation system. The angle and magnitude of rotor voltage are controlled to achieve independent control of electromagnetic torque and reactive power respectively. Space vector modulation (SVM) is used to address the limitations, of variable switching frequency and torque ripple, of hysteresis based schemes. The required voltage vector is generated in polar form. Hence, implementation of SVM for this vector is simpler compared to other methods reported in the literature. The proposed DTC is inherently a scalar control method. However, it has fast dynamic response, which is comparable to vector control. Simulation results for a DFIG system, during the variation of torque and reactive power, demonstrates the effectiveness of the proposed control strategy.