Investigation on noise and vibration origin in permanent magnet electrical machine for elevator

The effect of electromagnetic and mechanical characteristics in permanent magnet electrical machine for elevator on noise and vibration is presented. Some mechanisms of electromagnetic and mechanical interaction of the machine resulting in noise and vibration are analyzed and calculated. The main peaks of noise and vibration originate from switching frequencies and their harmonics and side band frequencies modulating by fundamental supply frequency at lower switching frequencies. Computational and experimental results are also compared. Noise and vibration resulting from electromagnetic forces dominates in the noise and vibration of PM electrical machine on rated load. When the exerting force frequencies coincide with modal frequencies of the stator, the motor can generate high noise and vibration peak.