Performance Analysis of Asymmetrical Rewound Six-Phase Permanent Magnet Assisted Synchronous Reluctance Machines

This paper investigates the performance of four permanent magnet assisted synchronous reluctance machines (PMaSynRM) with different winding configurations named as reference machine (three-phase star-connected winding), motor 1 (asymmetrical six-phase winding), motor 2 (symmetrical six-phase winding) and motor 3 (rewound five-phase winding). Four identical stators and one rotor were used to construct the four machines using the same copper volume as much as possible. The performance comparison has been conducted using Ansys Maxwell transient simulations for the healthy and for a fault case with one-phase open. At health case and rated condition, Motor 1 offers the superior performance where it has the lowest torque ripple, which is 21% lower than the reference machine. Moreover, it has 4.48% higher average torque and 0.2% higher efficiency than the reference machine. At fault case, Motor 1 provides the highest average torque, 66.56% higher than the reference machine, and 65.85% lower torque ripple. Motor 2 has the lowest torque ripple in the failure situation, 67.37% lower than the reference machine and 61.41% more average torque. Motor 3 offers 53.3% less torque ripple and 54.77% more average torque. These results on motor 1, 2 and 3 show that their changes in the stator lead to a huge decrease in torque ripple in case of an open-phase fault, compared to the reference motor.