750kV输电线路耐张塔绕跳间隔棒结构优化

Structure Optimization of Spacers on Jumpers of Strain Towers on 750 kV Transmission Line

750kV输电线路拉西瓦-官厅段位处西北高海拔地区,其耐张塔中相绕跳转角处的间隔棒线夹上电晕放电严重,对周围产生了可听噪声及无线电干扰的污染。为了对绕跳转角处形式和间隔棒结构进行优化,解决该处电晕放电问题,运用三维有限元法建立了750kV耐张塔模型,计算了绕跳转角处间隔棒的电场分布,结果表明中相绕跳由于转角陡、跳线成形差,对转角处间隔棒屏蔽作用较弱,因而导致该处间隔棒线夹上场强高达3540V/mm。针对该问题,提出了增大绕跳转角、增大间隔棒线夹曲率半径和加装屏蔽环或屏蔽球等优化方案,并进行了计算和比较,分析结果表明在间隔棒线夹上安装屏蔽球较为方便可行,能将间隔棒线夹表面最大场强降低至约2200V/mm,可有效抑制间隔棒的放电现象。该研究可为今后超、特高压线路绕跳形式、防晕间隔棒的设计提供研究经验和思路。

To suppress the corona, the electric field intensity on the jumper and spacers should be reduced by optimizing structures. Consequently, we constructed a three-dimensional calculation model of the strain tower to compute the electric field distributions of jumpers and spacers, and proposed and compared a variety of optimization schemes, such as increasing the angle of the jumpers, increasing the clamps of the spacers, and installing a grading ring or grading spheres on the spacers. The results demonstrate that installing grading spheres on the spacers is the most reasonable and feasible scheme, which can reduce the maximum electric field intensity from 3540 V/ram to 2200 V/ mm on the surfaces of the spacers.