基于微分环的输电线路雷电流非接触式测量方法  

Non-contact Measurement of Lightning Current in Transmission Line Based on Differential Loop

作　　者：姚陈果[1] 肖前波[2] 龙羿[1] 李成祥[1] 司马文霞[1] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030 [2]重庆市电力公司电力科学研究院,重庆401121

出　　处：《高电压技术》2012年第1期43-51,共9页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724504);国家自然科学基金(51177176)~~

摘　　要：雷电流的测量在电网雷电防护中至关重要,获取准确的雷电流大小以及波形才能采取正确的防雷保护措施。针对当前输电线路雷电流安全准确测量的难题,将脉冲功率测量技术中被广泛应用的微分环应用于输电线路雷电流的测量,提出了基于微分环的非接触式输电线路雷电流测量方法,并介绍了微分环测量雷电流的原理以及基于微分环的雷电流测量传感器的设计。实验室中冲击大电流的试验表明:针对不同的测量距离,通过选择适当的微分环尺寸及微分环匝数采用合理的屏蔽措施,并结合自积分,则该传感器能够准确反映被测电流的波形及幅值,且其具有安全性高、抗干扰能力强、线性度好、测量精度高等特点。最后基于FDTD建立了雷击输电线路的三维模型,对雷击瞬态磁场传播特性进行了仿真分析。结果表明:雷击输电线路时,杆塔周围的瞬态磁场能够准确地反映各导线上的电流波形及幅值情况,说明基于微分环的输电线路雷电流测量方法是可行的。Measurement of lightning current is essential for lightning protection in grid,because only if accurate amplitude and waveform of the lightning current is obtained can the correct lightning protection measures be taken.However,in high voltage power systems,it is almost impossible to directly measure the lightning currents accurately and safely.We put forward a contactless lightning current sensor for transmission tower based on the differential loop which has been widely used in the pulse power measurement technique,and it could measure the lightning current on overhead transmission lines contactless.Moreover,we introduced the principle of differential loop for measuring lightning current and the design of the detector.In laboratory,the lightning current was simulated by a high impulse current generator.The experimental results showed that the sensor can accurately reproduce the waveform and amplitude of the current generated by the high impulse current generator,based on a specific measuring distance under reasonable design.And this sensor has the advantages of safety,strong anti-interference ability,and good linearity and accuracy.To analyze propagation characteristics of the lightning transient magnetic field,a 3D model of transmission line struck by lightning was established.The results showed that the transient magnetic field around the tower can reproduce the waveform and the amplitude of the current on the wires when the transmission line is stoked.So the lightning measurement method based on the differential loop is feasible.

关 键 词：雷电流 架空输电线路 微分环 非接触 时域有限差分法 瞬态磁场 

分 类 号：TM835.2[电气工程—高电压与绝缘技术]