特高压交流架空线路用复合绝缘子均压特性研究

介绍了特高压交流架空线路用1 000 kV棒形悬式复合绝缘子电场分布计算及均压特性研究等情况,运用三维有限元法,比较了整体单支、1/3和2/3元件组串、1/6和5/6元件组串和一种1/6瓷质绝缘子及5/6复合绝缘子组串,结果可以看出,两复合绝缘子元件组串对电场分布没有任何改善,在结构上复合绝缘子采用整体单支比两元件组串的好;导线侧使用瓷质绝缘子,接地侧使用复合绝缘子组串,可以充分利用瓷质绝缘子良好的耐电弧性和复合绝缘子良好的憎水防污性,比采用整体单支复合绝缘子的电场分布均匀,使复合绝缘子元件端部密封处的电场强度降低了60%以上。计算分析了特高压绝缘子的电场分布,均压环经优化配置后,使整体单支复合绝缘子导线侧的电场强度小于320 V/mm,瓷质绝缘子和复合绝缘子组串,复合绝缘子承受的最大场强小于110 V/mm。

Study on Electrical Stress Grading of Composite Insulators for UHV Transmission Lines

Calculation of electrical stress distribution and grading performance of 1 000 kV composite insulator for UHV a.c.overhead transmission line is described.Comparison among one-piece unit,strings of 1/3 and 2/3 units,1/6 and 5/6 units as well as 1/6 porcelain unit and 5/6 composite units is performed.The results show that two-units string gives no improvement in stress distribution,the structure of one-piece unit is better than two-unit string in design,and applying porcelain unit to live end and composite units to earth end can fully take advantage of arc-resistant performance of porcelain insulator and hydrophobic performance of composite performance to achieve better stress distribution than one-piece insulator,reducing the electrical stress at end sealing of composite insulator by 60%.Calculation and analysis of the electrical stress distribution of UHV insulator are conducted.After optimization of grading ring the electrical stress at live end of one-piece insulator is less than 320V/mm,and the maximum value at composite insulator of porcelain-composite units combination is less than 110 V/mm.