阻抗不匹配对乘用车EMC传导发射测试结果的影响评估

Evaluation of the Impact of Impedance Mismatch on the EMC Conducted Emission Test Results of Passenger Cars

在按GB/T 40428标准进行车辆沿AC电源线的射频传导发射测试时,根据GB/T 6113.402标准给出的影响电源端传导发射测试结果不确定度的因素包括接收机的读数变化,人工电源网络与接收机之间线缆的衰减,人工电源网络的电压分压系数,接收机的修正,人工电源网络电压分压系数频率内插,人工电源网络与接收机之间阻抗的失配,人工电源网络的阻抗不理想,电源骚扰影响和环境影响等。本文主要研究人工电源网络与接收机之间阻抗失配对车辆沿AC电源线的射频传导发射测试的结果影响。研究表明人工电源网络与接收机之间阻抗失配会对车辆沿AC电源线的射频传导发射测试结果造成很大影响,为提高测试结果的准确性,推荐在人工电源网络与接收机之间增加50 Ω阻抗匹配网络。

When conducting the RF conducted emission test along the AC power line of the vehicle according to GB/T 40428 standard,the factors that affect the uncertainty of the conducted emission test result at the power supply end according to GB/T 6113.402 standard include the reading change of the receiver,the attenuation of the cable between the artificial power network and the receiver,and the voltage partial voltage coefficient of the artificial power network.The correction of the receiver,the frequency interpolation of the voltage partial voltage coefficient of the artificial power network,the mismatch of the impedance between the artificial power network and the receiver,the impedance of the artificial power network is not ideal,the influence of the power disturbance and the environmental impact.This paper mainly studies the influence of impedance mismatch between the artificial power network and the receiver on the RF conducted emission test results of the vehicle along the AC power line.The research shows that the impedance mismatch between the artificial power supply network and the receiver will greatly affect the RF conducted emission test results of the vehicle along the AC power line.In order to improve the accuracy of the test results,it is recommended to add a 50Ωimpedance matching network between the artificial power supply network and the receiver.