特高压交流线路Y型复合绝缘子串静电场分布

Static Electric Field Distribution of Ultra-High Voltage AC Line Y-Type Composite Insulator String

通过建立理想条件下特高压双回输电线路Y型复合绝缘子串的三维静电场有限元分析模型,计算了Y型绝缘子串和均压环表面电场分布。分析了串长比例、V串部分夹角和单双联串型对绝缘子串和均压环电场分布的影响。研究结果表明,串长比例和夹角对跑道型均压环和复合绝缘子表面电场强度最大值的影响与导线到上横担的距离密切相关。仅从静电场角度分析,建议串长比例为4 m/5 m(I部分/V部分),相比初设参数2 m/7 m,跑道环表面最大电场强度降低了1.6%,复合绝缘子降低了3.5%,相同串长位置(2 m)处承担电压降低了13.2%;鉴于夹角变化时均压环和复合绝缘子表面最大电场强度变化都在2%以内,建议夹角保持初设参数105°;单联Y型串各部分最大电场强度均小于双联Y型串,其中I串大环达8.7%,复合绝缘子21.9%,串型选择建议采用单联Y型串。

This paper presents results of the electric field distribution of UHV AC double-circuit transmission line of Y-type composite insulator string,using 3 D simulation models based on the finite element method( FEM) in ideal conditions. The impact of length of each part,angle,single and double units on electric field distribution has been analyzed. It is found that the effect is closely related to the distance from conductor to the upper cross arm. From the perspective of the static electric field,it is suggested that the length of I part and V part choose 4 m/5 m. Compared with the 2 m/7 m,the maximum electric field strength on the racetrack type ring decreased by 1. 6%,and 3. 5% on composite insulators,the potential distribution on the position of 2 m reduced13. 2%. As the angle change the maximum field strength on both the racetrack type ring and the composite insulator are less than 2%,and it is suggested the angle stay 105°. Compared with double units the maximum electric field strength of single units is much lower,which is 8. 7% on the racetrack type ring and 21. 9% on the sheath of the composite insulator,single unit is suggested.