Modeling of Contact Resistance in Ground System and Analysis on Its Influencing Factors

Proper calculation of contact resistance between grounding device and soil is important for raising the level of ground grids design and construction,as well as selecting suitable conductor sizes.Generally,it is not accurately considered in actual ground project for the sake of no accurate method for calculating.Consequently,we established a simulation model,by which calculations were made on the contact resistance under different conditions with ANSYS(finite element software).By theoretical calculation,conductor sizes and soil nature were figured out to be main factors affecting the magnitude of the contact resistance.To easily calculate the contact resistance of complex grounding grids,a simplified model was built based on original model,with which contact resistances of different grounding grids were calculated in CDEGS(software for grounding analysis).In order to give advices for design and construction of grounding,methods are proposed to reduce contact resistance in actual project.