Tooth Modulation Effect of Electromagnetic Force on Fractional Slot Concentrated Winding PMSM According to Slot Opening

Since slot opening has a great influence on airgap permeance, it is an important design variable that affects the airgap magnetic flux density and electromagnetic force harmonics. In addition, a tooth modulation effect, which indicates high-order force induces a low-order vibration mode has recently been revealed, and this effect also changes significantly by slot opening. Therefore, in this paper, the electromagnetic force and vibration characteristics considering the tooth modulation effect according to the slot opening of 10p12s motor were analyzed. First, electromagnetic forces of the lowest and pole number order force were analyzed according to the slot opening. Then, the spatial harmonic order that can induce low-order vibration mode was identified, and the vibration caused by high-order force was obtained. Finally, vibration of the motor was analyzed according to the slot opening.