摘要
Abstract
Grounding safety is one of the fundamental guarantees for the safe and stable operation of power systems,and grounding resistance,contact voltage,and step voltage are important indicators for measu-ring the performance of grounding grids.On the one hand,the author constructs a double-layer groun-ding grid model and uses the four pole method to measure the electrical resistivity of different soil moisture contents,exploring the changes in grounding resistance,step voltage,and contact voltage under different rainfall types and rainfall infiltration depths.Simulation shows that rainfall can reduce grounding resis-tance and step voltage,but initially leads to a slight increase in contact voltage;On the other hand,soil freezing and thawing all start from the surface soil.In the research,the formula for the relationship be-tween frozen soil temperature and soil resistivity under certain water content conditions was fitted through experimental data.From the perspectives of different frozen soil resistivity,freezing depth,and thawing depth,the changing trends of grounding resistance,step voltage,and contact voltage during soil freezing and thawing were analyzed.The results indicate that seasonal frozen soil poses significant safety hazards when the freezing depth exceeds the burial depth of the ground grid.The research conclusion can provide a certain theoretical reference for the design of grounding grids in power systems.关键词
降雨影响/季节性冻土/接地电阻/跨步电压/接触电压Key words
rainfall impact/seasonal frozen soil/grounding resistance/step voltage/contact voltage
