Shaft-to-frame voltage mitigation method by changing winding-to-rotor parasitic capacitance of IPMSM

Common-mode voltage (CMV) by switching pattern of space vector pulse width modulation (SVPWM) excites parasitic capacitance coupling in interior permanent magnet synchronous motor (IPMSM), and it finally causes shaft voltage. Among all parasitic capacitances, winding-to-rotor parasitic capacitance has the greatest effect on the shaft-to-frame voltage. In the study, mitigation method of a shaft-to-frame voltage is proposed by changing the winding-to-rotor parasitic capacitance. Specifically, modified winding shape is utilized for mitigate the shaft-to-frame voltage by suppressing the stator winding-to-rotor capacitance. In addition, electromagnetic shield is applied to suppress the effect of the end winding-to-rotor parasitic capacitance on the shaft-to-frame voltage.