Electromagnetic Vibration Characteristics Analysis of a Squirrel-Cage Induction Motor Under Different Loading Conditions

Electromagnetic vibration is an important excitation source for squirrel-cage induction motors. However, the electromagnetic vibration under various loadings has not been sufficiently analyzed. It is proposed in this paper that the electromagnetic vibration of motors under different loads can be obtained by analyzing the amplitude of the electromagnetic force wave. The Maxwell tensor method is employed to derive the spatial and temporal distributions of the radial force. This paper also calculates the radial force using the finite element method and decodes the calculated results using two dimensional fast Fourier transform (2D-FFT) to determine the amplitude of the electromagnetic force at the spatial order under different loads. In addition, through the modal analysis of the stator core, it can be concluded that in the case of nonresonance, the vibration response increases when the electromagnetic force of the first-order and second-order rotor slot harmonic increases. Finally, the conclusion is verified by separating the electromagnetic vibration of the motor using a vibration test rig.