A Method for Calculating Stator Core Vibration of Permanent Magnet Machine Considering Welding Slots for Automotive Application

To address the effect of welding slots on the circumferential modals of the stator core, this article proposes an equivalent modeling method of the stator based on a hybrid beam element model (HBEM), which equates the yoke part, the tooth part, and the yoke part with welding slots of the electric motor stator core into different beam elements. And then the overall stiffness matrix and overall mass matrix of the stator core are deduced from the coordinate transformations, and the circumferential mode frequencies and vibration shapes of the stator core considering the welding slots are accurately calculated and compared with the finite element calculation results. A fast calculation method for electromagnetic vibration of motors using the HBEM is further proposed based on the superposition theorem, which considers the influence of tangential force waves and the modulation effect of the stator teeth. Finally, the correctness of this fast calculation method of electromagnetic vibration is verified by using finite element method and experimental method.