Condition Evaluation and Reconstruction of Grounding Grid in 500 kV Hengli Substation

Operation condition evaluation of the grounding Grid in 500 kV Hengli Substation is carried out by using CDEGS analysis software,from the point of view of grounding resistance,contact voltage,step voltage,soil resistivity and soil structure,comprehensive analysis is carried out.Reconstruction scheme is proposed that abandon the outside grounding grid through cutting off the four steel flat connected the outside and the main grounding grid,and install 11 grounding shafts with HK-2 type physical resistance reduction agent around the main grounding grid.The grounding resistance can be down to 0.377 Ω to meet the design requirement,which can ensure the safety of operation and personal in substation.