1100kV直流电阻标准分压器电场仿真分析和方案设计

目前,我国直流电压比例标准的最高电压等级为800 kV,若直接套用该标准进行1100 kV直流电压互感器现场校准实验,其周围电场的分布仍不均匀,将导致准确度降低,故文中针对这些问题研究设计了1100 kV直流电阻标准分压器。本文基于Ansys仿真软件搭建了1100 kV直流电阻标准分压器的有限元模型,计算并分析了分压器周围和沿测量电阻层方向上的电场分布,得出了均压环的尺寸和位置对分压器周围最大场强的影响特性,通过合理设置均压环的圆心到地面的距离、内环半径、圆心到对称轴的距离,可大幅改善分压器周围最大场强。本算例中,分压器周围最大场强的大小从6869.37 V/mm降低到1566 V/mm,提高了绝缘水平;施加屏蔽电阻层后,沿测量电阻层上的电场强度减小到142.17 V/mm,且分布均匀,提高了测量准确度。本设计对分压器设计、制造、运行等部门有较好的借鉴作用。

Electric Field Simulation Analysis and Scheme Design of 1100 kV DC Resistance Standard Voltage Divider

At present,there are only 800 kV DC voltage ratio standards in China.If the original standards are applied directly on higher than 800 kV DC voltage transformers field calibration,the distribution of surrounding electric field is still uneven,which will lead to lower accuracy.Therefore,this paper studies these problems and designed a 1100 kV DC resistance standard voltage divider.This paper builds a finite element model of 1100 kV DC resistance standard voltage divider based on ANSYS simulation software,calculates and analyzes the electric field distribution around and along the voltage divider layer.The influence of the size and position of the grading ring on the maximum field strength around the voltage divider is obtained.By reasonably setting the distance from the center of the grading ring to the ground,the radius of the inner ring,and the distance from the center of the circle to the axis of symmetry,the maximum field strength around the voltage divider can be greatly improved.In this study,the maximum field strength is reduced from 6869.37 V/mm to 1566 V/mm,which increases the insulation level.It is necessary to apply a shielding resistance layer to reduce the electric field intensity along the measuring resistance layer to 142.17 V/mm,and the distribution is uniform,thereby improving the measurement accuracy.This design has a good reference for the design,manufacture and operation of the voltage divider.