A Way Used to Calculate the Least Impulse Grounding Impedance When Lightning Strike on the Grounding Grid
Zhong Yang · Insulators and Surge Arresters · 2012
In order to study on the characteristic of the impulse grounding impedance when lightning strike on the grounding grid,a equivalent circuit model of π type is presented,based on spark discharge equivalent radius,grounding grid is analyzed and calculated by using ATP-EMTP simulation software.The soil resistivity which is under ρ=1000 Ω·m is divided into four intervals,every interval corresponding to an effective area of the grounding grid.The fitting formula of impulse grounding impedance of corresponding interzone is obtained by using polynomial regression analysis software,the least impulse grounding impedance in different conditions can be easily calculated.A reference is provided for grounding engineering of lightning protection.