信号系统SPD的选用技术

雷电过电压侵袭是造成信号系统巨大损失的重要原因，因此对信号系统防雷技术的研究是非常必要的，安装SPD是减弱过电压危害的有效方法。结合实际工程经验和国家标准，分析比较了几种常见系统的SPD的选用方案；对平衡线路使用的SPD的工作原理进行了详细分析。利用Pspice软件，建立防雷原件的电气特性库，并对信号系统用的SPD进行了仿真分析，验证了SPD在线路中确实有导通大电流，提供较低的限制电压的作用。这对信号SPD的实际应用有一定的指导参考意义。

The Selecting Technology for SPD of Single System

The lightning over-voltage invasion cause so large a amount of damage to the single system that it is very necessary to research on the lightning protection technology for the single system, and installing SPD is an effective way to decrease the damage of lightning over-voltage. Engineering experiences and Industry Standards is considered, some method of selecting SPD for several common single systems is analysised; the working principles of balanced line are detailed analysised. The Pspice is used in the work, creating the libraries of devices used in lightning protection, simulating and analysising the SPD used in the single system, proving that the SPD used in the transmission lines can actually bleeder current to the ground and supply a low output voltage. The work may be useful to the engineering and application of SPD.