A study on the response characteristics of adjacent grounding grids under artificially triggered lightning strokes

Abstract Previous studies regarding the transient response of grounding systems have mainly focused on grounding grids with injected current, while there are few studies on adjacent unconnected grids. An "active-passive" grounding grid model was set up based on the artificially triggered lightning experiment, and the GPR data from 39 return strokes were measured. The results show the peak ratio of GPR between the two grounding grids caused by return strokes ranges from 9.6% to 17.3%, and the GPR decreases rapidly after reaching the peak and forms a subpeak. In addition, the 10–90% rise time and the time to half value of the passive grid are longer than those of the active grid. There is a good linear fitting relationship between the GPR peaks of the two grids and the injected current peaks. This shows that, under the joint action of soil dispersion and the resistance component of the active grid, the transfer potential of the passive grid becomes smoother and the amplitude decreases significantly, due to the attenuation of the high-frequency components. It shows there is a long-time difference between the GPR peak values of the two grounding grids, which is not affected by the injected current, and is almost unchanged.