Influence of Winding Structure on Unbalanced Magnetic Pull in Multi-Phase PMSMs

The unbalanced magnetic pull (UMP) brings an additional electromagnetic vibration and a decreased life time to the permanent magnet synchronous machines (PMSMs). In this digest, a 6-phase PMSMs with different winding structures is researched in order to investigate the influence of the winding structure on the UMP. The UMP forced on the 6-phase PMSM is analyzed through both the analytical method and the finite element method (FEM). It is found that the circulation current in the parallel branches will restrain the UMP that induced by the manufacturing errors, such as the eccentricity and magnetization error. It is also found that some high frequency UMP harmonics will be induced if the parallel branches in the winding are asymmetrically distributed.