季节因素对接地网安全性能的影响研究OA
Impact of Seasonal Factors on the Safety Performance of Grounding Networks
接地安全是电力系统安全稳定运行的根本保证之一,而接地电阻、接触电压和跨步电压是衡量接地网性能重要指标.首先搭建了双层接地网模型,采用四极法测量了不同土壤含水量的电阻率,探究不同降雨类型、不同雨水渗透深度情况下接地电阻、跨步电压和接触电压的变化规律,仿真表明降雨可以降低接地电阻和跨步电压,但在最初会导致接触电压略微增加;另外,土壤冻融均是从表层土壤开始,通过实验数据拟合出一定含水量条件下冻土温度与土壤电阻率的规律公式,并从冻土电阻率、冻结深度与解冻深度等不同角度,分析了土壤冻结融化时接地电阻,跨步电压和接触电压的变化趋势,结果表明季节性冻土在冻结深度超过地网埋设深度后会有极大的安全隐患.研究结论可为电力系统接地网设计提供一定的理论参考.
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.
李慧奇;王凯旋;宋云燕;李雁回
华北电力大学电力工程系,河北保定 071000华北电力大学电力工程系,河北保定 071000安徽华电工程咨询设计有限公司,合肥 230009华北电力大学电力工程系,河北保定 071000
降雨影响季节性冻土接地电阻跨步电压接触电压
rainfall impactseasonal frozen soilgrounding resistancestep voltagecontact voltage
《电瓷避雷器》 2026 (4)
84-92,9
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