由于大功率TEA CO2激光器系统中的液晶显示模块易于耦合电磁干扰, 从而影响激光器的正常工作, 本文研究了在瞬变电磁场辐照下预测液晶显示模块电磁兼容(EMC)能力的方法。分析了液晶显示模块集成于激光器系统时受干扰耦合的机理; 从场线耦合干扰的角度, 采用Taylor形式的BLT方程对液晶显示模块耦合的场线电磁干扰进行了分析计算, 并采用实验手段对预测结果进行了验证。计算结果显示: 连接线缆耦合电磁场在液晶显示模块数据线上产生的干扰电压为1 V, 超出了电路的噪声容限, 需要采取EMC控制措施保证液晶显示模块的工作性能。验证实验结果表明: 得到的EMC预测的结果能够正确反映液晶显示模块的实际EMC性能。该方法对大功率TEA CO2激光器电磁辐射近场区内电气设备的电磁兼容预测与设计具有指导意义。

The Liquid Crystal Display(LCD) module in a high power TEA CO2 laser is easy to couple with electromagnetic interference, so as to affect the normal work of the laser. Therefore, this paper explores the prediction method of Electromagnetic Compatibility (EMC)for the LCD module under transient irradiation in an electromagnetic field. The coupling mechanism of electromagnetic interference received by the LCD module integrated in the laser system was analyzed. On the basis of the coupling of field and line , the field line electromagnetic interference of the LCD module was analyzed and calculated by using the BLT equation in the Taylor form, then, the prediction results were verified by several experimentally. The experimental results show that the interference voltage produced by connect cables coupled with electromagnetic fields on the data lines of LCD display module is 1 V, and exceeds the noise margin of the circuit. So the EMC control measures must be taken to ensure the performance of the LCD module. Moreover, the verification experiments indicate that prediction results for the EMC has correctly reflected the actual EMC performance of LCD module. The method has a guiding significance for prediction and design of EMC of electrical equipment in high-power TEA CO2 lasers.