Underground substation, compact structure, small footprint, most of the substation and control equipment is located in the building, GIS type substation is often laid double or even three grounding grid.
In order to save land resources, urban substations such as 35kVspan>, 110kV, 220kV-class AC substations and 66kV DC substations are mostly GIS-type substations.
The following is a brief overview of the application of the uni Electric series grounding materials and other new grounding materials in the GIS type substation grounding field.
GROUNDING EXAMPLE OF 35KV-220KV BUILDING AND UNDERGROUND GIS TYPE SUBSTATION Unlike traditional open-type substations, most of the substation equipment is concentrated in 3 to 4 floors due to the large number of GIS equipment. The floor space is small, the number of equipment grounding lines is greatly reduced, and the primary grounding grid is buried and the lowest floor. In the cushion, waterproof layer and backfilled plain soil, most of the grounding lead wires are led out around the main grounding grid, crossing each floor, and finally connected with the lightning protection belt of the building/roof, and also serve as the down conductor for direct lightning protection.

The secondary grounding in the room is mostly laid by pure copper row and directly connected to the equipment through BVR copper cable. Another common design is to directly solder the copper wire or copper wire to the steel plate of the equipment foundation.