Impact of distributed parameters on conducted EMI in electric vehicles motor drive system

摘要

The effect of distributed parameters on conducted EMI is investigated in its motor drive system under load conditions for an electric vehicle. A conducted EMI testing platform was constructed for the system. By testing the conducted EMIs from the system under both load and idle conditions, the propagation paths of both high-and-low frequency differential-mode noise and common-mode interference were analyzed and the equivalent circuits were established. In frequency domain, the mechanism of the conducted EMIs was studied and the effect of distributed parameters on them was discussed. Tests show that high-frequency conducted EMI can be reduced by properly enlarging the distributed capacitances both between ground and power devices in the motor controller and between ground and debus.