多脉冲下架空线缆耦合雷电电磁波特性分析

Characteristic Analysis of Lightning Electromagnetic Wave Coupling on Overhead Lines with Multi-Pulse

传输线缆在电力输送和信号传输领域中扮演着十分重要的角色,传输线耦合雷电电磁波产生的过电压、电流对整个传输线系统产生很大的影响。本文通过建立架空线缆、闪电通道一体化模型。利用模拟8/20μs单脉冲雷电流及多脉冲雷电流进行试验,得出结论如下:架空线缆耦合电压波形以阻尼振荡波形式衰减;耦合电压幅值整体随冲击电流的增大而增大,多脉冲条件下耦合电压幅值与冲击电流峰值不是对应的比例关系;单脉冲冲击下,耦合的能量随冲击电流峰值以指数形式增加,多脉冲冲击下,耦合的能量整体随冲击电流峰值的增加而增加,但是当耦合电压出现重叠、互连现象时,其会在几微秒内耦合到大量的能量,从而出现低雷电流高能量的现象。试验所得结果对架空导线在实际的防雷保护中有一定的参考意义。

Transmission line play an important role in the field of power transmission and signal transmission.The coupled overvoltage and current generated by the transmission line with lightning electromagnetic waves have a great impact on the entire transmission line system.This paper establishes an integrated model of overhead cables and lightning channels.The experiment is carried out by simulating 8 single-pulse lightning current and multi-pulse lightning current.The conclusions are as follows:the coupling voltage waveform of the overhead cable is attenuated in the form of damped oscillation;the overall amplitude of the coupling voltage increases with the increase of the impulse current.Under the Multi-pulse condition,the amplitude of the coupling voltage is not proportional to the peak value of the impulse current.Under the impact of single-pulse,the coupled energy increases exponentially with the peak value of the impulse current.Under the impact of multiple pulses,the total energy of the coupling increases with the increase of the peak value of the impulse current.But when the coupling voltage is overlapped and interconnected,it will couple a large amount of energy within a few microseconds,resulting in the phenomenon of low lightning current but with high energy.The results obtained from the test have certain reference significance for the actual lightning protection of overhead cable line.