Direct Torque Fault Tolerant Control of Single-phase Open-circuit Fault in Dual Three-phase Permanent Magnet Synchronous Motor Based on Multistage Hysteresis Loop

Fault-tolerant control strategies based on direct torque control for dual three-phase permanent magnet synchronous motors are mostly based on the downscaling model of the motor after break fault, and different types of faults need to be analysed separately and controllers need to be switched before and after the fault. Therefore, this paper proposed a direct torque and fault-tolerant control strategy based on multi-stage hysteresis loop, while considering the positivity, negativity and amplitude of torque and magnetic link to select the voltage vectors for synthesis to improve the transient and steady state performance of the motor. On this basis, the fault characteristics of the motor after single-phase open-circuit fault are analysed, and the post-fault full-dimensional model is used for fault-tolerant control, which is simpler to control by modifying only the fault-tolerant current reference without modifying the controller. The excellent torque and harmonic suppression performance and fault-tolerant control performance of the proposed algorithm are verified by simulation.