【作者】 周学； 任万滨； 翟国富；

【Author】 (Military Apparatus Research Institute,Harbin Institute of Technology,150001,Harbin) ZHOU Xue REN Wan-bin ZHAI Guo-fu

【机构】 哈尔滨工业大学军用电器研究所；

【摘要】 继电器触点切断电流回路时在触点间形成电弧放电现象,触点间的电压以及流过触点的电流都以很高频率变化,导致严重的电磁干扰。提出了考虑了触簧寄生电感、触簧之间以及触簧与外壳之间寄生电容的触簧组电磁兼容模型,在此基础上建立了电弧传导发射共模与差模仿真电路模型,给出了其共模与差模干扰的传导路径。以一组银转换触点组为例,提取了其分布电感、电容参数,仿真了切断5A 直流的阻性负载情况下电弧对外发射的共模与差模电压在10kHz～10MHz 之间的幅频谱,其差模干扰发射电平在某些频率点超出了国军标规定的发射限值,应用中需要采取抑制手段。更多还原

【Abstract】 An electrical arc appears on the contacts of relay when opening a current above the minimum arc current in a circuit.Both the contact voltage and the current that flows into the are change violently due to arc discharge,which could bring serious EMI issues.An EMC model that takes into consideration the parasitic parameters which include parasitic induction of springs and parasitic capacitance between springs and shell was presented.Based on this model,an electrical circuit was created to simulate the common mode(CM)and the differential mode(DM)conducted EMI of arcing.The conducted paths for CM and DM EMI were also analyzed.After extracting the parasitic parameters of a silver spring set,the amplitude frequency characteristics of CM and DM conducted EMI between 10kHz and 10MHz were simulated when this spring set was opening a 5A DC resistive load.It has been revealed that the DM conducted EMI level exceeds the emitting limits of GJB 151 on some frequencies,which makes it necessary to suppress the DM conducted EMI in applications.更多还原