超高压同塔双回输电线路复合绝缘子电位分布研究

Study on Potential Distribution of Composite Insulator for EHV Double-circuit Transmission Lines

沿绝缘子串电场分布不均匀,确定并控制绝缘子串电位分布特别重要。基于有限元方法,考虑铁塔、分裂导线、避雷线等因素的影响建立了超高压输电线路复合绝缘子三维电场仿真计算模型,从而计算得到了沿复合绝缘子的电位、电场分布曲线。分析讨论了均压环、绝缘子型号对复合绝缘子电位、电场分布影响的规律和特点。结果显示:均压环对复合绝缘子两端附近电位、电场分布改善效果显著,安装了均压环后绝缘子各部分电场强度更小,沿绝缘子电位分布更为均匀;不同吨位的复合绝缘子电位分布稍有不同,绝缘子靠近高压端电位分布基本一致,靠近接地端相同长度绝缘距离大吨位绝缘子承担电压较高。

Potential distribution along the composite insulator is uneven. It is important to determine and improve the potential distribution of composite insulator strings. Based on finite element method, considering the effects of tower,bundle conductors, shielding line and so on, insulator three-dimensional electric field calculation models for the composite insulator of EHV transmission lines are set up. And the curve of potential distribution along the composite insulator strings is obtained. The impact of factors, such as grading ring and the type of insulators, on the potential distribution of insulator strings are analyzed. The results show that the grading nngs could significantly improve the potential, electric field distribution of composite insulator strings, and the potential and electric field distribution along the composite insulator is more uniform. The type of insulators have influence on the potential distribution of insulator strings.