微机通信中高压传输线对信号线的电感性干扰研究

Inductive Interference of High Voltage Transmission Line on Signal Line in Microcomputer Communication

矿用微机供电线路中通常是高压传输线 ,会对信号线造成很大的电磁干扰 ,尤其在开关开合瞬间电源上存在着高频干扰 ,如不采取措施 ,会直接影响微机的正常工作。本文根据这一特殊情况 ,首先建立了矿用微机设备传输线的供电模型 ,把多芯供电电缆中动力线对信号线的电磁干扰模式引入实际多导体传输线的供电系统中。分析了传输线对信号线的电感性干扰 ,并着重研究了开关吸合瞬间有尖峰脉冲作用下的电磁干扰。并对单脉冲和多脉冲的加载模式进行了比较。结果表明 ,当单脉冲作用时 ,干扰电压会随信号线与传输线的距离不同而有变化 ,最大可达 5 0 V。当有脉冲群作用时 ,干扰会更大 ,最大可达 5 0 0 V。

For the high voltage transmission line for supplying power circuit of microcomputer, it has great electromagnetism interference (EMI) on the signal line, especially at the moment of the switch works from 'on' to 'off'. If proper methods are not taken, it affects the microcomputer work properly. Using the EMI mode caused by the power cores to the signal cores in multicore mining power cables, this paper analyses the inductive interference produced by the three-pulse alternating current transmission line to the signal line, and puts emphasis on the study of the interference voltage in switch′s transient state with peak pulse put on, it compares the voltage difference between the single pulse and multi-pulse conditions. Results show that interference voltage changes with the distance between the transmission line and signal line, the biggest value can be 50V for single pulse and 500V for multi-pulse.