电力系统保护与控制
電力繫統保護與控製
전력계통보호여공제
Power System Protection and Control
2015年
18期
1-5
,共5页
高压直流输电%直流接地极%电流场%大地电场模型%有限元%地面感应电势
高壓直流輸電%直流接地極%電流場%大地電場模型%有限元%地麵感應電勢
고압직류수전%직류접지겁%전류장%대지전장모형%유한원%지면감응전세
HVDC%DC grounding electrode%current field%earth electric field model%finite element%earth surface potential
高压直流输电单极-大地回路方式运行时入地电流会在接地极周围的土壤中产生强电场,会对接地极附近电网的电力设备和地下金属管线等产生影响.针对接地极周围实际土壤的分布情况,建立了典型土壤模型和多层土壤模型,采用有限元法对典型接地极的地电位分布进行计算.比较了采用典型土壤模型和采用多层土壤模型下的直流输电接地极的接地特性以及对地面电位分布的影响.计算结果表明,在极址附近,接地极所在层土壤电阻率对接地电阻和跨步电压的影响较大,在离接地极数十公里范围内,深层土壤电阻率对地表电位的影响较大.
高壓直流輸電單極-大地迴路方式運行時入地電流會在接地極週圍的土壤中產生彊電場,會對接地極附近電網的電力設備和地下金屬管線等產生影響.針對接地極週圍實際土壤的分佈情況,建立瞭典型土壤模型和多層土壤模型,採用有限元法對典型接地極的地電位分佈進行計算.比較瞭採用典型土壤模型和採用多層土壤模型下的直流輸電接地極的接地特性以及對地麵電位分佈的影響.計算結果錶明,在極阯附近,接地極所在層土壤電阻率對接地電阻和跨步電壓的影響較大,在離接地極數十公裏範圍內,深層土壤電阻率對地錶電位的影響較大.
고압직류수전단겁-대지회로방식운행시입지전류회재접지겁주위적토양중산생강전장,회대접지겁부근전망적전력설비화지하금속관선등산생영향.침대접지겁주위실제토양적분포정황,건립료전형토양모형화다층토양모형,채용유한원법대전형접지겁적지전위분포진행계산.비교료채용전형토양모형화채용다층토양모형하적직류수전접지겁적접지특성이급대지면전위분포적영향.계산결과표명,재겁지부근,접지겁소재층토양전조솔대접지전조화과보전압적영향교대,재리접지겁수십공리범위내,심층토양전조솔대지표전위적영향교대.
Strong electric field will be produced in the earth around the grounding poles when HVDC transmission system operates in ground-return mode, which will influence electrical equipment nearby and the metallic pipelines underground. This paper builds a model of multi-layer soil and a typical soil model on basis of actual distribution of soil around the grounding poles, and then calculates surface potential distribution of typical grounding poles by finite element method. The grounding characteristics of DC transmission grounding electrode and the influence on earth surface potential distribution of the two models are compared. The results show that, the ground resistance and the step voltage around the site are much affected by the soil resistivity where the grounding locates. While the ESP which is within the range of tens of meters, is affected by the deep soil resistivity.
