Influence of Stator Core on the Vibration Behavior of Permanent Magnet Machines with Hairpin Winding

The fixation process of stator core is one of main uncertainties during design of permanent magnet (PM) machines, potentially impacting vibration behavior. Therefore, this paper investigates the effect of stator core joining processes, i.e., gluing and welding, on the machine vibration behavior. The eigenfrequency, eigenmode and damping ratio of two different stator cores are compared by conducting the finite element (FE) and experimental modal analysis. Based on the results, structural properties of two stator cores are effectively identified and verified. Furthermore, the harmonic response of the stator cores is simulated, and the vibrations of PM machines with gluing and welding stator cores are measured and compared. It is found that the Young’s modulus and damping ratio of gluing stator core is higher than that of the welding stator core, resulting in a lower vibration. The identified equivalent material parameters (EMPs) and modal parameters could be utilized for the further vibration prediction.