屏蔽双绞线抗电磁干扰研究及其在城轨车辆上的应用

Study on EMI-free of STP and its application in mass transit vehicles

针对城轨车辆上不同设备和子系统之间的电磁兼容问题,分析了用于设备和子系统互连的屏蔽双绞线的抗电磁干扰机理,并利用广义二端口网络,建立双绞线串扰简化模型。对屏蔽层不同端接方式进行了测试,并对测试数据进行分析,为屏蔽层合理接地提供了依据。最后给出了一个屏蔽双绞线应用于城轨车辆的实例。

In view of EMC of different equipments and subsystems in mass transit vehicles, EMI-free principle of STP （shielded twisted-pair wires） is analyzed. A simple crosstalk model is established using broad two ports net theory. A test model is built to test STP of shielding layer with different terminals. Through analysis on the test data, the shielding layer with reasonable terminals is obtained. Finally, an example of STP in mass transit vehicles is illuminated .