Comparative Study on Torque Performance of Five-phase Single-Stator and Double-Stator Permanent Magnet Synchronous Motors

This paper compares the torque characteristics of single stator permanent magnet synchronous motor(PMSM) and double-stator PMSM under different split-ratios, air-gap lengths and shaft diameters by finite element method. Firstly, the effects of split-ratio towards the torque characteristics of the two motor structures under different air-gap lengths are researched, the results show that the optimal split-ratios of the two motor structures do not change under different air-gap lengths, and the optimal split-ratio of the double-stator motor is greater than that of single-stator, and the torque of the double-stator motor is greater than that of single-stator motor with arbitrary split-ratio under the same air-gap length; Finally, the effects of the shaft diameter to the torque of the two motor structures are investigated, obtaining that with the increasing of shaft diameter, the electromagnetic torque of the single-stator motor is almost unchanged, however, the torque of the double-stator is gradually reduced, when the shaft diameter reached a certain extent, the electromagnetic torque of the double-stator motor is smaller than that of single-stator motor with the split ratio within a certain range, and the torque/quality ratio of the double-stator motor is smaller than that of single-stator motor with their optimal split ratio separately.