GIS based map drawing of soil corrosion to power grid earthing materials and analysis of main influencing factors

Abstract

In order to disclose the effect of soil on the corrosion of earthing metal materials in power grid in Shaanxi Province, 152 stations with related soil environment are selected, and the corrosion data of four earthing metal materials including carbon steel, hot-dip galvanized steel, copper and copper-clad steel in different substations and external environments are measured. Then the average corrosion rate of four kinds of earthing metal materials in Shaanxi is calculated by weighing experiment. Based on geographic data information system (GIS), the environmental soil corrosion rate map of metal materials is drawn, and the average corrosion rate of earthing metal materials in substations of different cities in Shaanxi Province is compared and analyzed. Simultaneously, the main factors affecting the corrosion of metal materials are analyzed combining with soil properties parameters. The results show that the average annual soil corrosion rate of eastern region is higher than that of western area in Shaanxi Province after the earthing metal material buried one year. The average corrosion rate of copper and hot dip galvanized steel is slower than that of carbon steel. Comparatively, the corrosion rate in the substation is higher than that outside the station, and soil moisture, pH and chloride content have obvious effects on the corrosion rate. This result can provide reference for the design of earth power grid in Shaanxi Province.