雷电对移动通信基站的危害及其防护

发布时间：2018-02-24 17:39

本文关键词： 铁塔 ADS软件天线电缆雷电流电压分布　出处：《内蒙古大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着3G、4G通信技术的发展,通信质量越来越受到人们的关注,移动通信基站作为通信系统中的重要组成部分,它的安全性、抗干扰性是影响通信质量的重要因素,其中雷电对其的影响和危害不容忽视。论文首先介绍了雷电对移动通信基站的危害及形式;其次,以雷电直击移动通信基站铁塔时,雷暴云、铁塔、接地网和大地无限远处形成的回路为模拟对象,选择TCS雷电流模型作为该回路的电流源,根据雷击铁塔时铁塔的特征、接地网表现的特性建立了铁塔、接地网的等效电路。考虑到雷击铁塔时,天线电缆屏蔽层与铁塔之间相互作用,建立了天线电缆-铁塔的等效电路;接下来,利用ADS软件,建立完整的雷击铁塔回路模型,并采用TCS雷电流模型作为该回路的电流源,仿真模拟了雷电直击移动通信基站铁塔后,铁塔主梁上雷电流分布、铁塔接地网上雷电流分布和电位分布、分两种情况讨论了天线电缆屏蔽层上感应电流分布以及天线电缆与爬梯之间的电压分布;根据仿真结果,提出了对铁塔、机房的直击雷防护措施和对线缆、设备等电位连接方式,并对比分析了增加防雷措施前后铁塔主梁的雷电流分布、接地网上电位分布;最后,利用呼和浩特地区某移动通信基站遭受雷击情况验证采取防雷措施的有效性。通过分析仿真数据得出如下结论:雷击铁塔后,铁塔四根主梁雷电流波形相同,在同一高度处电流幅值基本相同;铁塔接地网上对称接地体上的雷电流分布基本相同,电流的分布和接地体的布设形式有关,土壤电阻率、天线电缆屏蔽层是否与铁塔相连不会影响雷电流的波形和幅值;铁塔接地网各处的电位在103-105KV之间,各点的电位基本相同,可视为等电位体,电位随着土壤电阻率的增大而增大;天线电缆屏蔽层与铁塔连接时,垂直方向天线电流屏蔽层上的电流和它与爬梯之间的电压比天线电缆屏蔽层不与铁塔连接时要小,但水平方向天线电流屏蔽层的电流比不连接时大,并且它们都不受土壤电阻率变化的影响。采取防雷措施后能够减小铁塔主梁上雷电流、能够减小发生雷电反击的概率、减小天线电缆屏蔽层上的感应电流和与爬梯之间的电压,从而保护了基站,减少雷电对其的损害。
[Abstract]:With the development of 3G 4G communication technology, people pay more and more attention to the communication quality. As an important part of the communication system, the security and anti-jamming of the mobile base station are the important factors that affect the communication quality. The impact and harm of lightning on mobile communication base station can not be ignored. Firstly, the paper introduces the harm and form of lightning to mobile communication base station; secondly, when lightning strikes the tower of mobile communication base station, thunderstorm cloud, iron tower, The TCS lightning current model is chosen as the current source of the circuit. According to the characteristics of the tower when lightning strikes the iron tower, the characteristic of the grounding network is established. Considering the interaction between the shielding layer of antenna cable and the tower, the equivalent circuit of antenna cable and tower is established. Then, the complete circuit model of lightning tower circuit is established by using ADS software. Using the TCS lightning current model as the current source of the circuit, the lightning current distribution on the main beam of the tower, the lightning current distribution and the potential distribution on the grounding network of the tower are simulated after lightning strikes directly on the base tower of the mobile communication station. The distribution of inductive current on the shielding layer of antenna cable and the voltage distribution between antenna cable and climbing ladder are discussed in two cases. The equipotential connection mode of the equipment and the lightning current distribution of the main beam of the tower before and after increasing the lightning protection measures are compared and analyzed, and the potential distribution of the grounding network is also analyzed. The lightning protection measures are verified by lightning strike on a mobile communication base station in Hohhot area. By analyzing the simulation data, it is concluded that the lightning current waveform of the four main beams of the tower is the same after lightning strikes. At the same height, the amplitude of current is basically the same, and the distribution of lightning current on the symmetrical grounding body of tower grounding network is basically the same, the distribution of current is related to the form of grounding body, and the soil resistivity, Whether the shielding layer of antenna cable is connected with the tower will not affect the waveform and amplitude of the lightning current, the potential of the grounding grid of the tower is between 103-105 KV, the potential of each point is basically the same, it can be regarded as the equipotential body, and the potential increases with the increase of the soil resistivity. When the antenna cable shield layer is connected to the tower, the current on the vertical antenna current shield layer and the voltage between it and the climbing ladder are smaller than when the antenna cable shield layer is not connected to the tower. However, the current shielding layer of horizontal antenna is larger than that without connection, and they are not affected by the change of soil resistivity. The lightning current on the main beam of the tower can be reduced after lightning protection measures are taken, and the probability of lightning strike back can be reduced. The inductive current on the shielding layer of the antenna cable and the voltage between the antenna cable and the climbing ladder are reduced to protect the base station and reduce the damage caused by lightning.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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