Analysis and design of 18-slot/10-pole six-phase fault-tolerant permanent magnet synchronous motor for electric vehicles

This study analyses a double Y shaft 30 degrees winding for six-phase fault-tolerant permanent magnet synchronous motors and introduces a novel modular 18-slot stator topology used in high-performance electric vehicles with unequal teeth width and unequal slot size. The new topology adopts double-layer winding in the same phase and single-layer winding in the adjacent phase. Additionally, two new pole/slot combinations for the six-phase motor, 18-slot/10-pole and 18-slot/14-pole, are proposed by analysing the air-gap flux harmonics that are produced by the stator winding. In addition, the optimal design of the 18-slot/10-pole motor is determined by using the average torque and the torque ripple as indexes. The motor can run continuously in the range of 0-4 times the rated speed with a one-time short-circuit current, a high isolation capability in the different phases and a high efficiency. The final parameters and performance of the 18-slot/10-pole motor are provided.