海拔2500 m以上地区1000 kV交流线路外绝缘配置研究

Research on External Insulation Configuration of 1000 kV AC Transmission Line in Areas Above 2500 m Altitude

依据已建1000 kV交流线路的设计、运维经验,依托中国电力科学研究院等国内科研机构开展的绝缘子污闪、冰闪研究成果,按复合绝缘子工频、操作、雷电及覆冰闪络特性对海拔2500 m以上地区轻中冰区复合绝缘子配置进行了试验研究。试验表明,憎水性状态对复合绝缘子污秽闪络电压影响非常大,按弱憎水性设计,海拔0~5000 m地区1000 kV交流线路复合绝缘子长度可按9 m配置;按亲水性设计,随着海拔的升高,在9 m长度基础上需相应增加复合绝缘子的长度。同时研究发现,绝缘子表面覆冰进一步增加达到15 mm时,覆冰闪络电压显著下降,该种状况下需按覆冰闪络电压来选择复合绝缘子长度,海拔2500 m以下复合绝缘子均按9.75 m防冰伞型配置,海拔2500 m以上区域,复合绝缘子长度随海拔高度增加需相应增长。

Based on the design,operation and maintenance experience of the existing 1000 kV AC lines,and the research results of insulator pollution flashover and ice flashover conducted by China Electric Power Research Institute and other domestic scientific research institutions,the configuration of composite insulators in light and middle ice area over 2500 m is tested according to the power frequency,operation,lightning and ice flashover characteristics of composite insulators.The test shows that hydrophobicity has a great influence on the pollution flashover voltage of composite insulators.According to the weak hydrophobicity design,the length of composite insulators of 1000 kV AC lines in the area with an altitude from 0 m to 5000 m can be configured as 9 m.According to the hydrophilic design,the length of composite insulators should be increased correspondingly on the basis of 9 m length with the increase of the altitude.At the same time,it is found that when the ice coating on the insulator surface further increases to 15 mm,the flashover voltage of ice coating is reduced significantly.In this case,the length of composite insulators should be selected according to the ice coating flashover voltage.The composite insulators 2500 m atitude below and above are all configured with the anti-ice umbrella type of 9.75 m.The length of composite insulator increases with the increase of the altitude.