抄録
These days, a quiet induction motor is strongly demanded. Electromagnetic factor is main cause of vibration and acoustic noise of small induction motor. Electromagnetic forces and magnetostrictive forces are considered of origin of electromagnetic vibration and noise. In this paper, magnetostrictive vibration of ring of electrical steel sheets was simulated by mechanical Finite Element Method. Magnetostriction was assumed as external forces and they were added at each node of meshed ring. Resonant frequency and mode of ring were calculated. In steel sheet ring excited by PWM voltage source inverter, frequency spectrum of vibration of ring was measured and compared with calculated results. It was confirmed that these procedure simulated magnetostriction behavior of electrical steel sheets. Furthermore, electromagnetic forces of small induction motor was calculated and compared with magnetostriction data. It became clear that electromagnetic vibration was affected by the magnetostriction of steel. These results will be useful to reduce the acoustic noise and to develop quiet motors.
