均压环对覆冰特高压直流复合绝缘子电场分布的影响

摘要

本文对±800kV云-广特高压直流输电线路上的特高压复合绝缘子在覆冰情况下小均压环对绝缘子表面电场分布的影响进行了研究。首先介绍了有限单元法的基本原理,建立了±800kV复合绝缘子的模型,考虑到本文中采用的是双均压环,当复合绝缘子全部覆冰时,冰棱可能会覆盖到高压侧的小均压环上,因此需要研究小均压环的环径对绝缘子表面电场分布特性的影响。结果表明当小均压环的环径比伞群大时,绝缘子的电压和电场分布特性相对均匀。%Based on the first ±800kV Yun-Guang special HVDC project in the world,this paper presented the electrical field distribution of icing ultra high voltage（UHV） DC insulator influenced by the small corona ring.At first,the theory of the finite element method（FEM） was presented,the model of ±800 kV composite insulator was constructed by the FEM software.Taking into account it is used the double corona rings in this paper,when the ice cover all the composite insulator,the icicle may cover the small corona ring in the high voltage side,so it is needed to study the effects of the diameter of the small corona ring on the surface electric-field distribution.The experimental results show that the diameter of the small corona ring is bigger than the diameter of the insulator,the potentials and electrical field distributions are better.