摘要
进行高电压等级的直流电阻标准分压器设计时,不仅要减小最大场强以保证绝缘,还要减小测量电阻层附近的场强,以减小电晕电流和泄漏电流对分压器准确度的影响。针对研制的1 000kV直流电阻标准分压器,建立了有限元模型,用有限元软件计算了分压器的电场分布以及沿测量电阻层外表面纵向方向上的电场分布。计算结果表明:均压环对高压电极附近的电场具有明显的改善作用,最大场强从7 775V/mm下降到了1 457V/mm,位置从电极上部转移到了辅均压环附近;增大辅均压环的小环半径,或使辅均压环和主均压环的包络线更加平滑,都能减小辅均压环附近的场强,通过优化设计,分压器的最大场强减小到了1 175V/mm;由于屏蔽电阻层的屏蔽作用,沿测量电阻层外表面纵向方向上的场强减小到了141V/mm,而且分布均匀。
During the design of DC high voltage standard divider,it is necessary not only to meet insulation requirements by decreasing the maximum electric field strength,but also to decrease the interference on the divider＇s accuracy from leakage currents and corona currents by reducing the electric field strength around measuring resistor layer.Aiming at an established 1 000 kV DC voltage standard divider,a finite element model was established in the finite element software,then the electric field distribution of the divider and the electric field distribution along longitudinal direction of the outer surface of the measuring resistor layer was calculated.The results show that,the electric field around high voltage electrode is improved obviously by adding grading rings,e.g.the maximum electric field strength is lowered from 7 775 V/mm to 1 457 V/mm,and the position of the maximum electric field strength is changed from top of the high voltage electrode to around of the assistant grading ring;increasing radius of the assistant grading ring or smoothing the assistant grading ring and the main grading ring＇s envelope,either of the two methods can reduce the electric field strength around the assistant grading ring,e.g.according to calculation results,the maximum electric field strength of the 1 000kV DC voltage standard divider is reduced to 1 175V/mm with an optimal design;the electric field strength along longitudinal direction of the outer surface of the measuring resistor layer is reduced to 141V/mm and distributed uniformly because of the shielding effect of the shielding resistor layer.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2012年第11期2875-2880,共6页
High Voltage Engineering
基金
国网计量中心项目(JL81-12-004)~~
关键词
标准分压器
测量电阻层
有限元模型
电场分布
均压环
屏蔽电阻层
standard divider
measuring resistor layer
finite element model
electric field distribution
grading ring
shielding resistor layer
