Direct Torque Control of Low-Pulsation Dual Three-Phase Permanent Magnet Synchronous Motors Using Master-Slave Voltage Vector

In the traditional direct torque control process of dual three-phase permanent magnet synchronous motors, there are relatively large current harmonics as well as flux and torque fluctuations. To solve the above problems, this paper proposes a new low-pulsation direct torque control strategy for dual three-phase motors based on the duty cycle distribution of master-slave virtual vectors. Firstly, this strategy adopts the direct torque control strategy of virtual vector synthesis to achieve the suppression of harmonic currents. Next, the voltage vectors of the dual three-phase motor are divided into master control virtual vectors and slave virtual vectors. The duty cycles of the master-slave virtual vectors are recalculated and distributed according to the evaluation function. In one cycle, there is the joint action of the master-slave virtual vectors and zero vectors to achieve the precise control of torque and flux. The results show that the proposed strategy effectively reduces the torque and flux pulsations and suppresses the harmonic currents.