Influence of Winding Structure on Electromagnetic Vibration of Dual-Three-Phase Permanent Magnet Synchronous Machines

The unbalanced magnetic pull (UMP) brings an additional electromagnetic vibration and a decreased life time to the permanent magnet synchronous machines (PMSMs). In this paper, a dual-3-phase PMSMs with different winding structures is researched in order to investigate the influence of the winding structure on the electromagnetic vibration. The magnetic fields and radial forces in the dual-3-phase PMSM are comprehensively analyzed. It is found that the circulation current in the parallel branches will restrain the additional radial force and UMP that induced by the eccentricities. It is also found that some high frequency harmonics in UMP and torque ripple will be induced if the parallel branches in the winding are asymmetrically distributed. The analysis results are validated by the finite element analysis (FEA) and experiment.