Research on the electromagnetic performance of less rare-earth interior V permanent-magnet synchronous machine

Improving the reluctance torque and reducing the consumption of permanent magnets (PMs) are two crucial research directions for the current automotive motors, due to expensive PMs. To meet the above requirements, a less rare-earth interior V permanent-magnet synchronous machine with the high reluctance torque is designed in this paper. To obtain the optimal design scheme, the influence of different combinations of PM width and thickness on the electromagnetic performance is investigated under condition of the same PM volume. It proves that the ratio of the reluctance torque and the total electromagnetic torque can exceed 60%. Furthermore, the torque ripple is reduced from 11.7% to 3.5% at 1945rpm and from 19.8% to 9.2% at 7000rpm respectively, by using the rotor skewing method. Considering the cross coupling effect, the d-axis and q-axis inductances is investigated under different d-axis and q-axis current. On this basis, the efficiency of the whole working region is obtained.