高电压技术
高電壓技術
고전압기술
HIGH VOLTAGE ENGINEERING
2012年
5期
1192-1198
,共7页
司马文霞%骆玲%袁涛%杨庆%雷超平%姜赤龙
司馬文霞%駱玲%袁濤%楊慶%雷超平%薑赤龍
사마문하%락령%원도%양경%뢰초평%강적룡
土壤电阻率%水分蒸发%直流接地极%溢散电流%接地极温升%温度分布
土壤電阻率%水分蒸髮%直流接地極%溢散電流%接地極溫升%溫度分佈
토양전조솔%수분증발%직류접지겁%일산전류%접지겁온승%온도분포
soil resistivity%water evaporation%DC grounding electrode%leakage current%the grounding electrode temperature rise%temperature distribution
为了更准确地分析接地极的发热情况,确保接地系统的安全运行,通过土壤温升模拟试验,获得了土壤在一定温度范围内的电阻率与温度、含水量的变化规律,试验结果表明:当温度较高时,土壤水分蒸发加快,土壤电阻率迅速增大,并呈指数上升。基于试验结果,结合电流场理论及传热学原理,建立了简单直线型接地极的发热仿真模型,从仿真结果中发现:土壤电阻率的变化会影响接地极表面的散流分布,从而改变接地极附近土壤的温度分布。对比传统计算模型中将土壤电阻率视为恒定的情况,该模型计算结果说明接地极附近土壤温升速度更快。试验及仿真结果说明,计算时考虑土壤电阻率的温度特性对接地极发热的影响,将有利于接地极的安全设计和维护。
為瞭更準確地分析接地極的髮熱情況,確保接地繫統的安全運行,通過土壤溫升模擬試驗,穫得瞭土壤在一定溫度範圍內的電阻率與溫度、含水量的變化規律,試驗結果錶明:噹溫度較高時,土壤水分蒸髮加快,土壤電阻率迅速增大,併呈指數上升。基于試驗結果,結閤電流場理論及傳熱學原理,建立瞭簡單直線型接地極的髮熱倣真模型,從倣真結果中髮現:土壤電阻率的變化會影響接地極錶麵的散流分佈,從而改變接地極附近土壤的溫度分佈。對比傳統計算模型中將土壤電阻率視為恆定的情況,該模型計算結果說明接地極附近土壤溫升速度更快。試驗及倣真結果說明,計算時攷慮土壤電阻率的溫度特性對接地極髮熱的影響,將有利于接地極的安全設計和維護。
위료경준학지분석접지겁적발열정황,학보접지계통적안전운행,통과토양온승모의시험,획득료토양재일정온도범위내적전조솔여온도、함수량적변화규률,시험결과표명:당온도교고시,토양수분증발가쾌,토양전조솔신속증대,병정지수상승。기우시험결과,결합전류장이론급전열학원리,건립료간단직선형접지겁적발열방진모형,종방진결과중발현:토양전조솔적변화회영향접지겁표면적산류분포,종이개변접지겁부근토양적온도분포。대비전통계산모형중장토양전조솔시위항정적정황,해모형계산결과설명접지겁부근토양온승속도경쾌。시험급방진결과설명,계산시고필토양전조솔적온도특성대접지겁발열적영향,장유리우접지겁적안전설계화유호。
In order to analyze the soil heating around the grounding electrode more accurately and to ensure the grounding system operation safely, by a simulation experiment of rising in the soil temperature, we analyzed the changing regulation of the soil resistivity With the temperature and water content variation. The experimental results show that, at a higher temperature, the water in the soil evaporates quickly, leading to a rapid increase in soil resistivity with an exponential trend. Basing on the experiment results, we established a heating simulation model of a simple linear electrode with the combination of the current field theory and the heat conduction principle. The results show that the soil resistivity variation can influence the leakage current distribution on the grounding electrode surface, thus change the temperature distribution of the soil around the electrode. Compared with the traditional calculation model with constant soil resistivity, this model is characterized with faster temperature rise. The results of experiment and simulation benefit safer grounding electrode design and better maintenance when considering temperature characteristic of soil resistivity.