nowadays in view of metallic grounding materials in power system is facing lots of problems, such as corrosion, the difficulty of transportation and construction, easy to be stolen and high cost, and so on. Thus, a new type of grounding material, i.e. flexible graphite composite grounding material, it can meet the requirements of corrosion resistance of grounding material and thermal stability of the grounding material of trans-missionline towers, under the condition of power frequency current and high-frequency lightning current scattering into the ground in the case of short-circuit fault and lightning strikes, which is strongly proposed& widely used in the transmission line and distribution by china power grid.(China Southern Power Grid and National Grid)
The corrosion resistance of the flexible graphite grounding material and the steel type grounding material was compared by the soil simulation solution corrosion tests. The contact performance with different soils of the two materials was analyzed by the actual contact resistance measurement test. The thermal stability and the impulse current effective length of this grounding material were studied by means of simulation calculation. The results show that the high-current capability flexible graphite grounding material has a strong anti-corrosion characteristic, whose reliable service life can exceed 30 years.
Compared to the round steel grounding material, the contact resistance with the soil can be reduced by approximately 30%, and the impulse current effective length can be increased by about 30%.
it has been through the application in 110kV and 220kV transmission line tower grounding grid, it is shown that the new grounding material can meet the requirements of practical engineering .