Study on Three-Level Inverter Direct Torque Control Based on Torque Prediction

Aiming at excessive torque ripple shortcomings caused by direct torque control of synthesizing voltage vectors in the threelevel inverter,a kind of new predictive control method was proposed to determine reference voltage vectors of the inverter according to errors of the flux and torque. Then this switching voltage vectors were synthesized with space vector pulse width modulation (SVPWM). The simulation results show that under the conditions of protection of switching frequency,the control method can lessen the torque ripple and maintain waveforms of the stator flux nearly round and sine character of the current is nice.