高海拔220kV输电线路绝缘子串与并联间隙雷电冲击绝缘配合研究

Lightning Insulating Co-ordination Between Insulator String and Parallel Gap Device of 220kV Transmission Line at high altitude area

运行经验表明,并联间隙(parallel gap device,PGD)能有效地降低由雷击引起的输电线路绝缘子损坏故障率,但目前高海拔地区的绝缘子串与并联间隙的绝缘配合研究还很薄弱。因此,在特高压工程技术(昆明)国家工程实验室进行了负极性标准雷电冲击电压下220kV瓷、复合绝缘子串及不同间距的并联间隙雷电冲击闪络及伏秒特性试验研究。分析了不同绝缘子串对其并联间隙的雷击闪络特性和伏秒特性的影响;并结合并联间隙与绝缘子串的绝缘配合原则和电弧路径,确定了并联间隙保护绝缘子串的最优间距。结果表明:绝缘子串电场分布会影响并联间隙雷电冲击闪络特性;推荐的并联间隙对绝缘子串具有良好的保护作用。

The operating experience shows that the parallel gap device （PGD） can effectively reduce the insulator damage caused by the lightning strike. However, the insulating co-ordination research between the insulator and the parallel gap device at high altitude areas is still inadequate. For this reason, the standard negative lightning flashover characteristics and voltage-time （V-t） characteristics experiments on a 220 kV composite insulator, a 220kV porcelain insulator string and their parallel gap devices were carried out in the National Engineering Laboratory （Kunming） for UHV Engineering Technology. Based on the test results, the flashover and V-t characteristics effect of PGDs on different insulators were analyzed. By combining the insulating co-ordination regulation with arc paths, the optimal distances for PGDs protection of the insulator strings were obtained. The result indicates that, the electric-field distribution of insulator affects the lightning flashover characteristics of PGDs; the recommended PGDs have excellent protective function to insulator strings.