Influence of Stator Slot Bottom Width on Electromagnetic Vibration and Noise of Asynchronous Motor

The electromagnetic vibration and noise level of the asynchronous motor affects the performance and life of the motor. In order to study the causes of electromagnetic vibration and noise. This paper takes a four-pole squirrel-cage asynchronous motor as the research object, establishes an asynchronous motor's magnetic-solid-acoustic multi-physics simulation model, analyzes the distribution characteristics of electromagnetic vibration and noise. The electromagnetic noise of the asynchronous motor is mainly generated by the radial electromagnetic force on the stator teeth. By adjusting the stator slot bottom width, the air gap magnetic density can be changed, so as to optimize the radial electromagnetic force and achieve the effect of weakening the electromagnetic vibration and noise of the motor. First, the air gap magnetic density between the stator and the rotor is analyzed by the combination of numerical analysis and finite element method. The Maxwell stress tensor method is used to calculate the radial electromagnetic force, which is consistent with the results obtained by the finite element simulation. The time and space character of the radial electromagnetic force are obtained through spectrum analysis, and then the order and frequency of the radial electromagnetic force are obtained. Combined with harmonic response analysis and acoustic radiation theory, the vibration and noise results of the squirrel-cage asynchronous motor are obtained. Finally, by analyzing the electromagnetic vibration and noise results of asynchronous motors under different stator slot bottom widths, the study found when the slot bottom width is 12.4mm, a lower level of the electromagnetic noise can be obtained.