大功率TEA CO_2激光系统的电磁兼容设计

EMC design of high-power TEA CO_2 laser system

大功率TEA CO2激光系统工作时产生的强电磁干扰对激光系统内部及相关外部设备的电子系统具有很大的干扰和破坏作用。本文对大功率TEA CO2激光系统的电磁干扰进行了分析计算,在此基础上对该系统进行了电磁兼容(EMC)的设计。硬件设计手段分别采用了对电磁干扰源和控制子系统进行屏蔽、系统合理布局与布线、滤波隔离;软件设计则采用了数据冗余纠错、冗余化操作和数据鉴别等抑噪和纠错技术,有效抑制了干扰电磁波在系统内外的传播,解决了大功率TEA CO2激光系统的EMC问题。测试结果表明,EMC的设计,使电源线和温度传感器信号线中的干扰电压分别降低了26dB和4dB,干扰频谱最强处为96dBμV/m,干扰场强满足GJB151A-97中RS103的要求。这些结果表明,改进后的激光系统有很高的可靠性。

The strong Electromagnetic Interference （EMI） generated in the operation of a high-power TEA CO2 laser system has high interference and damage to the electronic systems inside and outside the laser system itself. This paper analyzes the reasons for EMI from the high power TEA CO2 laser system and then designs the Electromagnetic Compatibility（EMC） of the laser system based on the analysis and calculation of the EMI.Two methods, hardware method and software method, are presented to suppress the propagation of the interference electromagnetic wave from the high power TEA CO2 laser. The hardware design adopts electromagnetic shielding for interference sources and controlling sub-systems, layouting systems and wirings appropriately, and filtering isolation, while the software design uses the noise depression and error corrections including data redundancy error correction, redundancy operation and data identification. The tested results show the disturbing voltages of the power cable and signal line of the temperature cable sensor have decreased by 26 dB and 40 dB respectively and the largest disturbing spectrum in interference fields is 96 dBμV/m, which satisfies the requirements of RS103 in standard GJB 151A-97. These results reported here prove that the proposed method can guarantee the high reliability of the laser system.