Research on Vibration and Noise of Induction Motor under Variable Frequency

Studies have substantiated that the vibration and noise produced by the iron core of an electromagnetic device are closely related to the magnetostriction of the iron core silicon steel sheet. Moreover, when the induction motor works under the condition of frequency conversion, the symmetry of the core silicon steel sheet will change, and the distribution of the vibration and noise field of the motor will be asymmetric, which will aggravate the vibration and noise. This paper completes the experimental measurement and analysis of the electromagnetic characteristics and magnetostrictive characteristics of silicon steel sheets. The magnetic field of a 1140 V/75 kW variable-frequency motor is calculated analytically based on the analytical method, and the stator/rotor magnetic induction intensity and permeance are calculated separately to obtain the air gap magnetic density and the radial electromagnetic force. The vibration and noise of the 1140 V/75 kW variable-frequency motor are analyzed by the finite element method, while the magnetization curve and magnetostrictive characteristic curve of a silicon steel sheet under different conditions are considered. An experimental platform is built to measure and analyze the vibration displacement and acceleration of the variable frequency motor, which verifies the correctness of the proposed scheme. Considering the influence of the magnetostrictive effect will make the result of calculating the vibration and noise of variable-frequency motors more accurate.