1000 kV交流输电线路耐张塔带电作业电位转移电弧电磁辐射特性

Electromagnetic Radiation Characteristics of Potential Transfer Arc During Live Working on 1000 kV AC Transmission Line Tension Tower

超特高压输电线路等电位带电作业电位转移过程会出现明显间歇性电弧放电(电位转移电弧)现象,电弧产生的电磁辐射可能会影响周围智能设备的正常稳定工作,因此,研究电位转移电弧的电磁辐射特性具有重要意义。基于1000 k V交流输电线路耐张塔带电作业电位转移电流实测波形,利用希尔伯特变换对其进行频谱分析,获得了电位转移电流的频带分布,根据天线理论建立了带电作业电位转移电弧电磁辐射特性仿真模型,对转移电弧的辐射电磁场进行了计算,获得了转移电弧的辐射电磁场分布规律。结果表明:电位转移电弧电流呈高频振荡,其峰值可达1000 A左右,主要频率分布为13~20 MHz;转移电弧产生的辐射电场强度峰值远大于磁场强度,两者均随距离的增大快速衰减,且在金属导体附近分布较为集中;当频率为16.5MHz时,杆塔附近的电场和磁场强度最大值分别为1.5 k V/m和1.9 A/m左右。

There will be obvious intermittent arc discharge(potential transfer arc)in the process of equipotential live working of UHV transmission lines.The electromagnetic radiation generated by the arc may affect the normal and stable operation of the surrounding intelligent equipment.Therefore,it is of great significance to study the electromagnetic radiation characteristics of potential transfer arc.Based on the measured waveform of potential transfer current in live working of 1000 k V AC transmission line tension tower,the frequency spectrum of potential transfer current is analyzed by Hilbert transform,and the frequency band distribution of potential transfer current is obtained.According to the antenna theory,the simulation model of electromagnetic radiation characteristics of potential transfer arc in live working is established.The radiation electromagnetic field of transfer arc is calculated,and the radiated electromagnetic field distribution of the transfer arc is obtained.The results show that the potential transfer arc current presents high-frequency oscillation with a peak value of about 1000 A,and the main frequency is distributed in 13~20 MHz.The peak of the radiated electric field intensity generated by the transfer arc is much greater than the magnetic field intensity,both of which decay rapidly with the increase of distance,and are more concentrated near the metal conductor.When the frequency is 16.5 MHz,the maximum electric field and magnetic field intensity near the tower are about 1.5 k V/m and 1.9 A/m,respectively.