A study on indirect stator-quantities control strategy for Brushless doubly-fed induction machine

In this paper an indirect stator-quantities control (ISC) strategy for Brushless doubly-fed induction machine (BDFIM) is presented. The algorithm of calculating phase increment of control winding(CW) flux space vector in a sample period is obtained. The proposed ISC strategy is developed at the static two-axis model and can be used to control both the electromagnetic torque and CW flux in static reference frame. The simulation results show the feasibility of this method for BDFIM. Compared with classic direct torque control(DTC) for BDFIM, the torque ripple is significantly reduced at low frequencies and the CW flux and current waveform are improved in ISC system. Rotating coordinate transformation is not required in this method. Less parameters are used and the structure of the system is concise and clear as well.