A New Direct Torque Control Strategy to Reduce the Torque and Flux Ripples of the DFIM

There are various methods being proposed with Direct Torque Control (DTC) and Direct Power Control (DPC) methods without switching frequency composition and with constant switching frequency. In this paper, a new Predictive DTC (PDTC) technique for the Doubly Fed Induction Machine (DFIM) at constant switching frequency and with reduced torque and flux ripples criteria is presented, in order to provide good steady-state and fast dynamic performances. The proposed method is especially designed to operate at a considerably low constant switching frequency. With restricted switching frequency, this control is convenient for high power drive and generator applications; in addition, the proposed control method allows implementing a technique that reduces the switching power losses of the converter. Finally, the effectiveness of the control method is compared with the DTC strategy and is presented by simulation results. The predictive DTC method effectively reduces the torque and flux ripples at low switching frequency, even under variable speed operation conditions as compared to DTC method.