基于多导体传输线理论的煤矿电磁干扰研究

Research on electromagnetic interference in coal mine based on MTL theory

针对煤矿井下电磁干扰严重,电力线与信号线铺设距离较近,当电力线产生浪涌电压时会对信号线传输的信号产生较大干扰,导致接收器接收信号错误,引起误报或错报问题,应用多导体传输线理论,对电力线、信号线和参考大地建立模型;同时由于传输线重力相差较大,以及煤矿下非线性大型设备众多,应用FDTD(时域有限差分法)求解不平行多导体传输线在各时空离散点处的电压、电流迭代计算式;通过MATLAB编程研究了当电力线产生浪涌电压时对信号线的干扰,探讨了当传输线长度改变,电力线与信号线之间距离改变,信号线离地高度改变时,信号线终端电压的变化情况,为提高安监系统的可靠性提供依据,对保障煤矿安全具有重大意义。

This paper focused on serious electromagnetic interference in coal mine, and the close distance of power line and signal line. When there is surge voltage on power line, the signal line will be severely interfered, leading to fault signals received by receiver, then causing false positives or misstatement. Then use MTL（multiconductor transmission line） theory to set up a model of power line, signal line, and the ground. Moreover, because the lines are of large difference in gravity, and there are many nonlinear large equipment in coal mine, FDTD（finite difference time domain） is applied to deduce voltage/current iteration expressions at discrete points of time and space. Then three kinds of situation is discussed with MATLAB programming, which are the length change of transmission lines, the distance change between power line and signal line; the height of signal line. By analyzing the voltage response at the end of signal line, this paper provides basis for improving reliability of monitoring system, and has significance in security of coal mine safety.