电动汽车电机驱动系统分布参数对传导电磁干扰影响研究

Effect of Distributed Parameters on Conducted EMI in Electric Vehicle Motor Drive System

构建了电动汽车电机驱动系统传导电磁干扰测试平台,研究电动汽车电机驱动系统带载工况下分布参数对传导电磁干扰的影响.通过测试比较电机驱动系统带载工况下和空载工况下产生的传导电磁干扰,分析系统高低频差模干扰和共模干扰的传播路径,建立相应的等效电路,在频域内分析了传导电磁干扰产生的机理和分布参数对传导电磁干扰的影响.测试结果表明,适当增大电机控制器内部功率器件对地分布电容和直流动力线缆对地分布电容可减小系统产生的高频传导电磁干扰.

The effect of distributed parameters on conducted EMI was investigated for the motor drive system of an electric vehicle under load conditions. A conducted EMI testing platform was constructed for the system. By testing the conducted EMI in 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 EMI 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 dc-bus.