基于等效界面电荷的分层土壤结构地电位分析  

Ground Potential in Layer-Soil Structures Based on Equivalent Interface Charge

作　　者：张俊[1,2] 曹晓斌 金炜东[1] 张思渊[3] 张彼德 ZHANG Jun;CAO Xiaobin;JIN Weidong;ZHANG Siyuan;ZHANG Bide(School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China;Ganzi Power Supply Company,State Grid Sichuan Electric Power Corporation,Ganzi 620001,China;School of Electrical Engineering and Electronic Information,Xihua University,Chengdu 610051,China;Southwest Electric Power Design Institution,CPECC,Chengdu 610021,China)

机构地区：[1]西南交通大学电气工程学院,成都610031 [2]国网四川省电力公司甘孜供电公司,四川甘孜626000 [3]西南电力设计院有限公司,成都610021 [4]西华大学电气与电子信息学院,成都610051

出　　处：《电瓷避雷器》2022年第4期146-154,共9页Insulators and Surge Arresters

摘　　要：直流输电过程中,接地极和大地土壤承担着散流作用,电流散流区域的土壤模型是准确计算地电位和电流场分布的关键,而格林函数是研究土壤模型的重要手段。直流输电工程中的接地极选址问题,一直备受关注,往往选址确定后,极址周围土壤结构基本确定,因此通过接地极位置调整以优化电场、电位分布,降低环境影响,有工程应用价值和研究意义。本研究通过分析基本的水平双层结构土壤模型,将电位分布结果拆分为直接效应和界面电荷积累效应,建立了界面积累电荷分布理论,得到由四种电荷效应构成的系数矩阵,以此分析了某直流输电工程,极址移动带来的电位电场变化规律。得出结论,在距接地点固定范围内,当ρ_(4)>ρ_(1)>ρ_(3)时,极址越接近低电阻率层,电位越低,但电场会增加。当ρ_(4)>ρ_(1)<ρ_(3)时,极址越接近高电阻率层,电场越低,但电位会增加。工程上应以电场或电位的最值点作为极址位置。The grounding electrode and earth-soil structure is real critical for scattering current in DC transmission project,then model establishment of layer-soil structure has a great influence on computing of electric field and electric potential on area of scattering current,while Green function is a core method.It is always common concern on position of grounding electrode in DC transmission project,because earth-soil structure is generally fixed as long as locating specific position of grounding electrode.So by position adjustment of grounding electrode to optimize electric field and electric potential to reduce environmental impact,that is valuable for doing research on DC transmission project.As case of double-layers soil structure,the electrical effect is separated to two sections,one is direct electric charge,another is accumulation electric charge on interface of the layers.Theory of interface accumulation charge is brought up through coefficient matrix described by four types of electric charge.Then based on a HVDC project,analyze the vary regular of electric field and potential duce to position moving about grounding electrode.In the condition of fixed distance to grounding electrode,it is revealed that there is a lower electric potential during the position of grounding electrode move to lower resistivity soil(for instanceρ_(4)>ρ_(1)>ρ_(3)),while electric field will raise.On the other hand,there is a lower electric field during the position of grounding electrode move to higher resistivity soil(for instanceρ_(4)>ρ_(1)>ρ_(3)),while electric potential will raise.The project should choose minimum electric potential or minimum electric field as position of grounding electrode.

关 键 词：散流电流 格林函数 等效界面电荷 地电位分布 分层土壤结构 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM862