变电站接地网引下线氧浓差腐蚀仿真计算研究  

Simulation Calculation of Oxygen Concentration Difference Corrosion of Grounding Grid Lead-down Line in Substation

作　　者：安韵竹[1] 田海鹏 姜映辉 胡文国 安炳臣 AN Yunzhu;TIAN Haipeng;JIANG Yinghui;HU Wenguo;AN Bingchen(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;State Grid Binzhou City Bincheng District Power Supply Company,Binzhou 256600,China;Jining Huayuan Thermal Power Co.,Ltd.,Jining 272000,China)

机构地区：[1]山东理工大学电气与电子工程学院,山东淄博255000 [2]国网滨州市滨城区供电公司,山东滨州256600 [3]济宁华源热电有限公司,山东济宁272000

出　　处：《山东电力技术》2023年第9期1-9,共9页Shandong Electric Power

基　　金：国家自然科学基金项目(51807113)。

摘　　要：变电站接地网长期运行存在明显腐蚀问题,基于有限元法建立变电站接地网引下线腐蚀三维模型,分析不同材料、形状以及表层不同破损情况下的接地网引下线的腐蚀情况。计算结果表明:地面至地面以下20 cm区域的氧气摩尔浓度差异大,该区域电极表面电流密度比其他区域电流密度大,即发生了氧浓差腐蚀;当引下线表层镀膜完整,并且孔隙饱和度在0.20~0.35之间时,镀锌扁钢引下线比铜覆扁钢接地网引下线表面电流密度小,保护效果好;当孔隙饱和度在0.35~0.8之间时,镀锌扁钢引下线比铜覆扁钢引下线表面电流密度大,保护效果差;当引下线表层镀膜完整时,镀锌扁钢比镀锌圆钢引下线表面电流密度小,腐蚀速率小;氧浓差对表层镀膜完整的引下线的腐蚀影响较轻;当接地网引下线地下埋藏部分镀锌表层局部破损时,表层腐蚀孔周围电流密度较大,腐蚀较为严重;当接地网引下线地下埋藏部分镀锌表层腐蚀殆尽时,地面至地面以下20 cm的电流密度显著高于其他区域,氧浓差腐蚀现象显著。The substation grounding grid has obvious corrosion problems in long-term operation.Based on the finite element method,a three-dimensional model of the corrosion of the grounding grid lead-down line was established to analyze the corrosion under different materials,shapes and surface damage.The calculation results show that the difference of oxygen molar concentration from the ground to the area 20 cm below the ground is large,and the current density of the electrode surface in this area is higher than that in other areas,resulting in oxygen concentration corrosion.When the surface coating of the lead-down line is complete and the pore saturation is between 0.20 and 0.35,the galvanized flat steel lead-down line is smaller than the surface current density of the copper flat steel grounding grid lead,and the protection effect is good.When the pore saturation is between 0.35 and 0.8,the galvanized flat steel lead-down line has a larger current density than the copper flat steel lead-down line,and the protection effect is poor.When the surface coating of the lead-down line is complete,the galvanized flat steel is smaller than the surface current density of the galvanized round steel lead-down line,and the corrosion rate is small.The effect of oxygen concentration difference on the corrosion of the complete lead-down line of the surface coating is light.When the grounding grid leads to the underground buried part of the galvanized surface layer is partially damaged,the current density around the surface corrosion hole is large,and the corrosion is more serious.When the galvanized surface layer of the buried part of the grounding grid is corroded,the current density of 20 cm below the ground to the ground is significantly higher than that of other areas,and the corrosion phenomenon of oxygen concentration difference is significant.

关 键 词：接地网引下线 镀锌钢 铜覆钢 氧浓差腐蚀 

分 类 号：TM862[电气工程—高电压与绝缘技术]