Research of variable-speed and constant-frequency double-fed generator based on DTC

The paper presented the direct torque control technique of the VSCF doubly fed wind power generator from the theoretical analysis and explained its working principle and substance. According to theoretical analysis, ABB variable-speed constant-frequency drive units were established to achieve chain simulation model with MATLAB7. Through simulation analysis of the motor under different speeds, simulation waveforms were obtained. From the waveform can be seen that the frequency of the output current in the doubly-fed generator stator side is constant in the circumstances when the rotation speed varies. Therefore the correctness of theory analysis on the VSCF section of ABB drive unit was validated.