Magnetostriction Effect on Vibration in Switched Reluctance Motors

Electromagnetic forces are considered the main source of motor vibration. Similarly, magnetostriction also deforms motor cores periodically like the electromagnetic forces, therefore serving as another factor of motor vibration. In this study, the contribution of magnetostriction on motor vibration is investigated by comparing the vibration of two switched reluctance motors. The two motors were made of two types of core materials with significantly different magnetostriction. The relationship between the deformations caused by electromagnetic forces and equivalent magnetostriction forces is explained. The vibration of the two motors is compared in both finite element analysis and experiment. The results reveal that magnetostriction reduces the breathing-mode vibration by cancelling the vibration caused by the electromagnetic forces.