The grounding resistance is an important index to judge the performance of grounding devices. In order to reduce the impulse grounding resistance of box grounding device with radiation

the simulation experiment of different grounding devices is applied in the condition of two-layer soil

the influence of horizontal branch on impulse characteristics and dispersion distribution of different grounding bodies is studied.The results show that

in case of single horizontal grounding device

when the branch is 120° and three sections structure

the resistance reducing effect of the modified grounding body is the best.Compared with the normal box grounding device

three sections structure with a horizontal branch and branch be 120° can reduce the inductance

the discharge current of the end of the branch is increased

the discharge of the spark is more intense

so that the average percentage of resistance reducing is up to 10 %. Adding the horizontal branch is effective method to reduce the impulse grounding resistance.