Analysis Of The Motor Electromagnetic Vibration Characteristics

The vibration characteristic of motors is always ignored when they are designed. In that case, there are lots of motors exist problems of excessive vibration and noise. Typically the motor,as a power source of a system,will produce the electromagnetic excitation. This excitation is one of the main vibration excitations of the whole system. In order to reduce noise and vibration of a motor drive system, we have to do some research on low noise motor system design. How to obtain more accurate electromagnetic excitation properties and structural characteristics become a key technology of low noise motor system design.This thesis targeting on Y801-2 motor, analyzed the radial electromagnetic excitation characteristics of the motor and the vibration characteristics of the structure. Optimized solutions proposed on reducing electromagnetic vibration of the motor. Through the subsequent simulation and experiment, the electromagnetic vibration characteristics of the motor which was under load were studied. The main contents are as follows:1. Analytical method and finite element method were used to obtain the electromagnetic force of squirrel cage motor under no-load operating conditions. The magnetic potential and the permeability were used in the analytical method for obtaining the approximate electromagnetic force, ignoring the negative impact of the unbalanced three-phase inverter power. The finite element theory was based on two-dimensional finite element, combined with Maxwell stress tensor method. As the rotor is skewed rotor,the paper took a multi-section equivalent processing. Through the measured characteristics of the excitation conditions of the motor, simulation model was redefined. Finally, the spectral characteristics of the electromagnetic force were analyzed and he actual effects of the two calculation methods were compared.2. The segment modeling and modal synthesis method were used for solving the system to get the motor vibration mode. Amending the simulation model compared with the measured modal several times. Finally, through the MAC calculation and comparison of the natural frequencies obtained a credible simulation model.3. By solving the transient response of the electromagnetic force, obtaining the response of the motor. The measured values were used to verify the correctness of the calculated electromagnetic force. For reducing the electromagnetic force and the vibration of the motor,the modifications of the rotor slot number and the rotor groove size were made under the premise of doing little change to the motor performance. Vibration responses of the critical points were used to evaluate the effect of the motor modifications.4. The electromagnetic force of the motor under different loads was calculated.Compared with the measured load response, the vibration characteristics of the motor under varying load conditions were analyzed.