Study on the performance of multi‐branch modular permanent magnet motor affected by magnetic pole segmentation

Abstract

To better address the requirements of integrated equipment, here, a multi-branch modular permanent magnet motor using a toroidal winding with reverse turn coils is proposed. High-speed motors have a large winding span, and the use of a toroidal winding with reverse turn coils in place of lap windings can effectively shorten the length of the motor end. Motor modularisation can improve production, assembly efficiency, and the maintenance economy. To innovate the windings from a basic toroidal winding, a modularised toroidal winding with reverse turn coil is proposed which enables the motor to be decoupled in electrical and mechanical structures. The inductance parameter calculation and finite element simulation verification are carried out on the new winding structure and the lap windings. The feasibility of the 60-degree phase toroidal winding with a reverse turn coil structure with reverse turns is also assessed. The no-load back electromotive force of the new winding structure is a square wave, which will bring certain torque fluctuations. To improve the performance of the motor, the method of radial magnetic pole segmentation is used, and the new magnetic pole is analysed and verified by the segmented magnetic circuit. Finally, the combination of magnetic pole segmentation is explored, and the effect of different segmentation methods on the performance of the motor is compared.