Comparative Investigation of Dual Three-Phase Permanent Magnet Synchronous Machines With Different Winding Configurations

The winding configurations of dual three-phase permanent magnet (PM) machines are comparatively investigated. The distribution level of the two three-phase winding sets is defined to indicate the degree of winding uniformity, and its relationship with electromagnetic performances is focused. The classic 48-stator-slot/8-rotor-pole dual three-phase interior-PM machine is taken as a case study, and four different winding configurations are analyzed based on theoretical tools including winding factors, winding functions and newly defined coil vectors. Moreover, finite element method (FEM) is employed to validate the analyses on both healthy and faulty conditions. It is revealed that the windings with low distribution levels benefit from less magnetic couplings between the two winding sets, indicating the enhanced fault-tolerances, while the cases with high distribution levels exhibit more symmetrical magneto-motive forces (MMFs) and thus less local saturations, implying the improved overloading performances. As a result, the distribution level can be treated as an indicator of the dual three-phase windings. A prototype machine is fabricated and tested for experimental validations.