Research of Control Strategy for Fault-Tolerant Hybrid Excited Axial

Fault-tolerant hybrid excited axial field flux-switching(FT-HEAFFS) motor is a novel type of doubly salient stator-type permanent magnet motor with advantages of short axial size, simple rotor structure, high torque density and strong fault tolerance, which is suitable for electric driving system of electric vehicle. To improve the fault-tolerant operating performance and reduce the copper loss of motor, the fault tolerant control strategy of the FT-HEAFFS motor based on model predictive torque control(MPTC) is proposed in this paper.

Under the condition of three-phase four-leg inverter topology and principles of constant magnetomotive force and the minimum copper loss, the simulation research of fault tolerant control system based on structural characteristics and mathematical model of a 6/13-pole FT-HEAFFS motor is done by the control of MPTC and direct torque control respectively. The simulation results show that the two control methods can keep the torque and flux-linkage almost unchanged when the copper loss reduced,which ensure the stable operation of system after single-phase open circuit fault tolerance. Compared with the direct torque control, the fault tolerant control system of FT-HEAFFS motor under the model predictive torque control has smaller torque and flux linkage ripple, which is more suitable for the application in FTHEAFFS motor speed control system