Impulse performance of underground insulating wall near grounding device under lightning strike

When lightning current is injected into the grounding device, large ground potential rise may occur near the grounding device. When grounding devices of power system are built near civic facilities in the earth, it is necessary to restrain the ground potential rise around the grounding device. The influence of the insulating wall on the impulse characteristics of a 110kV substation grounding grid was studied. Impulse current was injected into the grounding grid and the ground potential rise nearby was measured. Results showed that the ground potential is apparently restrained behind the insulating wall, which means that the insulating wall can provide fine protection to the facilities near the grounding device.