Influence of Concentric and Unequal-Turn Windings on Vibration of Induction Machines Considering Supply With Low-Order Harmonics

As the wide application of power electronics devices, supply containing low-order harmonic becomes more and more common in industry. It may cause the significant vibration of induction motors (IMs). This study firstly analyzed the time-space distribution characteristics of the additional electromagnetic force caused by the low-order harmonics in supply. Then, an improved concentric and unequal-turn windings is designed and its impact on unconventional vibration of IMs is also analyzed. The increase ratio of force amplitude between the force in different cases is defined, by which the force characteristics of IMs with supply containing low-order harmonics and concentric and unequal-turn windings can be revealed under different load conditions. With a 32-kW IM, harmonic response analysis and experimental validation are also carried out, the results show that, with concentric unequal-turn winding, the vibration in different frequency bands can be reduced effectively, the average vibration can be suppressed from 89.7dB to 86.9dB.