Vibration Analysis of Three-Phase Squirrel-Cage Induction Motor With Different Winding Configurations

This paper presents a novel investigation into the vibration behavior of squirrel-cage induction motors, considering the influence of stator winding configurations and pole numbers. The primary contribution of this work is providing the first comprehensive comparative analysis of winding types across multiple pole numbers from a vibration perspective, offering specific design guidance for vibration mitigation. The analysis of the 48-slot induction motors is conducted with 4, 8, and 16 poles, and compares three winding types: distributed windings (DW), pseudo-concentrated windings (P-CW), and concentrated windings (CW) across various layer configurations. The comparison is performed at constant speed under steady-state conditions with a fixed supply frequency of 50 Hz for all motors, resulting in synchronous speeds of 1500 rpm for 4-pole, 750 rpm for 8-pole, and 375 rpm for 16-pole motors. The magnetic flux density harmonics and radial force density distributions are analyzed using a combination of analytical approaches and finite element analysis. This study also performs modal analysis for mode shape and natural frequency up to eighth circumferential order. It is shown that the configuration of winding plays an important role in vibration characteristics and that each pole number has an optimal configuration. Results indicate that increasing pole numbers reduces vibration amplitudes, whereas a four-layer P-CW presents better performance under low slot-per-pole-per-phase values and performance comparable to DW under high values. The experimental validation on the 4-pole baseline motor with a 2-layer DW under steady-state operation confirms the accuracy of the numerical findings.