基于改进双电流探头法的EMI噪声源内阻抗测量  

EMI noise source impedance measurement based on modified dual-current-probe approach

作　　者：赵波[1,2] 封志明[2] 赵敏[1] 水利民[2] 姚敏[1] 

机构地区：[1]南京航空航天大学自动化学院,南京200016 [2]江苏省计量科学研究院,南京210007

出　　处：《东南大学学报（自然科学版）》2009年第S2期87-91,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家质检总局科技计划资助项目(2008QK104)

摘　　要：提出了一种应用于EMI噪声源内阻抗测量的改进双电流探头法.首先,分别利用2个标准电阻代替被测噪声源内阻抗接入测试回路,或将被测噪声源内阻抗短路,依次测量上述3种测试回路中注入探头输入电压和检测探头输出电压,得到3个测试回路方程,并由此得到测试回路阻抗的幅值与相位.然后,将EMI噪声源接入测试回路,重复上述测试步骤,通过计算即可确定被测EM I噪声源内阻抗的幅值与相位,测试结果接近矢量网络分析仪标准测试结果.对AC-DC开关电源噪声源内阻抗的分析结果表明,随着频率的上升,其共模噪声源内阻抗和差模噪声源内阻抗分别呈减小和增大的趋势.A modified dual-current-probe approach applied to the electromagnetic interference(EMI) noise source impedance measurement is proposed.First,the EMI source impedance under test is replaced by two standard resistances or short-circuited.The input voltages of the injection probe and the output voltages of the test probe in the three circuits are measured,and three circuit equations are obtained.The amplitudes and phases of the equivalent impedances can be calculated by solving the three equations.Then,the EMI noise source is connected to the test loop.The amplitudes and phases of the EMI noise source impedances are acquired by the above steps.The experimental results are close to those by a vector network analyzer.Moreover,the analysis results of the noise source impedance of an AC-DC switch mode power supply show that with the increase of the frequency,the common mode impedance decreases while the different mode impedance increases.

关 键 词：电磁兼容 电磁干扰 噪声源内阻抗 双电流探头法 

分 类 号：TN03[电子电信—物理电子学]