电动汽车传导性干扰的电磁兼容性研究

Study on conducted EMC of electric vehicle

电动汽车产生的电磁干扰强于传统汽车,尤其是驱动系统产生的共模传导电流不但严重干扰车辆内部电子设备的整车运行,还向周围环境辐射强烈的电磁干扰。为通过减小驱动系统的共模电流,来降低电动车辆的磁场辐射强度,介绍了阻性耦合、感性耦合和容性耦合,并且给出了在电动汽车布线中减小感性耦合与容性耦合的具体措施;从电池的物理结构和电路模型入手,建立了电动汽车电池组与底盘之间的分布电容模型;着重分析了驱动系统的共模干扰源和共模干扰路径,提出了抑制共模干扰的具体办法;最后进行了电动汽车辐射强度试验。研究结果表明,通过抑制电动汽车驱动系统的共模电流,可以有效抑制车辆的磁场辐射强度,使车辆满足GB/T 18387对电动汽车磁场辐射发射限值的要求。

The electric vehicle generates more electromagnetic interference than the traditional cars. Especially,the power train system＇ common mode current affect the vehicle＇s electronic equipment seriously and radiate strong electromagnetic interference to the ambient environment. In order to reduce the magnetic radiation through the suppression of the common mode current,the resistance coupling, capacitive coupling and inductive coupling were introduced, and the suggestions of reducing the inductive coupling and capacitive couplingin the electric vehicle muting system were proposed. The Stray capacitance model between the battery pack and chassis was established. The battery＇s physical structure and circuit model were both considered during the establishment. Importantly,the source and propagation path of the common mode interference was analyzed. The inhibiting methods of the common mode interferences were proposed. The experiments result verifies that magnetic radiation is reduced through the suppression of the common mode current of the power train system,and the vehicle＇s magnetic radiation meets the requirement of GB/T 18387.