论控制室的电磁兼容

Discussion on Electromagnetic Compatibility of Control Room

电子式控制系统的电磁兼容(EMC)系指在可能的电磁环境中,电子系统仍然具有正常的工作能力且不会成为环境中的一个电磁污染源。一般用"抗扰度"来衡量电子式控制系统在电磁环境下的抗干扰能力;用"发射"来表明其对环境的电磁污染。通常应用于工业过程的控制系统面临着各种各样的电磁干扰(EMI),既不可能、也不应该将抑制干扰的功能完全由控制系统本体去承担,这就必须在控制工程的实施过程中采取各种措施去保证控制系统在工业电磁环境中的正常运行。针对设备选型的技术规格书、交流低压供电系统的零地电压、控制室的静电防护、照明灯具的电磁兼容、机柜内部继电器的电磁兼容、控制室内电缆系统的电磁兼容等,论述了在控制室设计中与电磁兼容相关的几个问题。

Electromagnetic compatibility （EMC） of electronic control system means electronic system still work properly and will not be a source of electromagnetic pollution in electromagnetic environment. ＂Immunity＂ is generally used to measure anti interference ability of electronic control system in electromagnetic environment. ＂Emission＂ is used to indicate its electromagnetic pollution to environment. A control system in industrial process is facing all kinds of electromagnetic interference （EMI）. Anti-interference function can not and should not be undertaken by control system itself completely. Various measures must be taken during engineering implementation to ensure normal operation of control system in industrial electromagnetic environment. Several issues related to electromagnetic compatibility in control room design are expounded from the points of blowing： technical specification for equipment selection; neutral ground voltage for AC low voltage power supply system; electrostatic protection in control room; electromagnetic compatibility of lighting lamps; electromagnetic compatibility of relay in cabinet; electromagnetic compatibility of cable system in control room, etc.