Resistance Reducing Agent Grounding Characteristics Of Transmission Line Tower Grounding Network And Ptimization Studies

The grounding grid of transmission line tower is the most basic lightning protection facility.Its low grounding resistance is an important guarantee to prevent line insulator from flashover and trip.The grounding resistance reduction measures are mainly including grounding resisitance reduction agent,grounding module method and vertical grounding method currently.These methods are effectively to grounding resisitance reduction.However,they can not be applied to mountainous areas.There are problems of inconvenient construction and low drag reduction efficiency in mountainous areas.Therefore,it is of practical engineering value to study the grounding resistance reduction strategy with high soil resistivity.In this paper,lightning protection grounding calculation software CDEGS is adopted to study the grounding characteristics and resistance reduction strategies of transmission line towers grounding grid with high soil resistivity in mountainous areas.The main research contents completed include:establish the common steel pipe tower and four comers tower grounding grid model in simulation software CDEGS,respectively.The simulation calculation is carried out for the actual grounding resistance reduction efficiency and influencing factors of grounding resistance reduction methods,such as grounding resistance reduction agent,new type of grounding resistance reduction material,and extension grounding grid method.The influence rules of soil condition,ground area,ground current frequency,ground material and other factors on the ground resistance reduction efficiency are analyzed.And the resistance reduction strategy of grounding grid of tower and pole with high soil resistivity is proposed with the new type of graphite composite grounding material.Taking the transformation project of 220kV Chengchuan I line and 220kV Longma line in Shandong central mountainous areas as an example,analysis was conducted briefly on the practical application effect of grounding resistance reduction transformation of tower in areas with high soil resistivity.The research content of this paper can provide reference for the actual transmission line tower grounding design and resistance reduction transformation.And it can provide reference for lightning protection design of overhead transmission line.