地闪雷电流间接测量技术

针对在高塔上设置分流器或套线圈直接测量雷电流存在的困难，提出了地闪雷电流间接测量技术，并专门研制了单匝正交环天线，用以对地闪LEMP水平磁场及雷电流的方位进行测量，同时采用声光差定位系统获取测点与闪电通道的距离，再根据电流与其产生的磁场的关系进行反演计算，从而在实现对雷击点定向的同时，完成对雷电流的间接测量。利用该项技术，从测得的20组磁场数据中选用2组，根据同步获得的测点与雷击点间的距离，得出了2个雷电流波形，依据这2个电流波形，采用时域有限差分法计算得出的测点处磁场波形与实际测得的波形均具有良好的一致性。

Indirect measurement of cloud to ground lightning current

To overcome the difficulty of the direct measurement of the lightning current using diffluent instrument or Rogowski coil, an indirect measurement technology of lightning current was proposed. Firstly, the magnetic fields and the direction of the lightning were obtained by the self developed crossed square loop antennas, and the distance between the lightning channel and the test point was got by the sound light gap system. Then the lightning current could be calculated by the measured magnetic fields according to their relationship. The proposed technology can achieve the indirect measurement of the lightning current and judge the direction of the lightning stroke point at the same time. With this technology, two typical magnetic waveforms were chosen to be analyzed from the twenty measured data, and the lightning current waveforms were got based on the distance between the lightning channel and the test points. With the solution of this lightning current, the magnetic waveforms at the test points were calculated by the finite difference time domain（FDTD） method. Compared with the measured waveforms, they have a good agreement.