机械制冷机是提供红外载荷工作所需低温环境的主要设备, 其驱动系统的传导干扰是影响红外载荷精度的重要因素。传导干扰中的共模干扰具有较高的分析难度, 为研究其机理, 以某红外用机械制冷机及驱动系统为研究对象, 使用一种新型多物理域联合仿真的方法对共模干扰机理进行定量分析, 并通过实验测试验证了仿真模型的准确性。最终对其干扰路径及干扰源特性进行了分析, 并总结出共模干扰机理。结果表明: 测试频段内制冷机的寄生参数是影响共模干扰通路的最主要因素, 但随频率增加, 输入输出电缆的寄生参数对干扰通路的影响逐渐增大, 同时, 干扰机理显示: 系统产生的共模干扰最可能导致 CE102标准在频段500 kHz~1 MHz干扰超限。

Cryocooler is an important equipment to provide low temperature working environment for infrared device. However, its driving system′s conducted interference severely affects the precision of the infrared loading. It′s not easy to analyze the common-mode part included in conducted interference. To study the common-mode interference mechanism, based on an existing infrared system project′s cryocooler and its driving system, the mechanism was quantitatively analyzd using a new multi-physics co-simulation method and the model′s accuracy was verified by specific experiment measurement. Finally, the characteristic of disturbance pathway and source were analyzed and the mechanism of the common-mode interference was concluded. Results show that, the parasitic parameter of the cryocooler is the most important factor of transmission path within the range of test frequency. However, with frequency increase, the effect of cable′s parasitic parameter is increasing and can′t be ignored. The interference mechanism concludes that the common mode interference produced by system may induce the overrun of the CE102 standard from 500 kHz to 1 MHz.