The Study On Grounding Grid Design And Reducing Resistance Measures Of Substation In High Soil Resistivity Region

The resistance of substation grounding grid is generally higher in high soil resistivity area.According to the actual situation,they are difficult to achieve for some resistance reduction measures.or some resistance reduction measures can be achieved,but the effect is not good.So it is necessary to study effective methods to reduce grounding resistance in high soil resistivity region.Based on the analysis of geology and climatic conditions in Shijiazhuang area and the statistics on the grounding resistance of substations in Shijiazhuang,the conclusion is drawn that the grounding resistance of substations in mountainous areas is generally high.According to the characteristics of high resistance area,the resistance reduction measures,vertical grounding,artificial soil improvement,electrolysis of the earth,are analyzed,and discussed the principle of shunt coefficient calculation,and the relationship between secondary equipment safety and ground potential rise,introduced the method of using the high resistance layer of the earth to improve the touch voltage and step voltage,design of grounding grid for Shi-yan substation,which is in the high soil land rent area,according to the actual situation,with CDEGS software for analysis and calculation,by comparative analysis of various schemes,using the horizontal grounding grids with unequal spacing layout,and with the inclined earth grounding method to reduce resistance,the number of ground poles is eight,arranged in the corners of horizontal grounding,the conductor length is 80 meters,and the angle between the ground electrode and the horizontal ground is 30 °,the grounding resistance,contact voltage and step voltage meet the design requirements.For the Lian-jiazhuang substation in the high soil resistivity region,using the formula to analyze and calculate the grounding grid,using the horizontal grounding grids with unequal spacing layout,and with two deep ground electrode,which are 50 meters length,to reduce resistance,and this solution meets the design requirements.