超高压交流线路长串绝缘子的冰闪特性

Icing Flashover Characteristics of EHV AC Transmission Line Insulator Strings

在覆冰、污秽、积雪、高海拔等因素综合作用下,输电线路绝缘子的绝缘性能将显著降低,因此研究其闪络特性对线路外绝缘配合具有重要意义。在带电覆冰下对超高压线路长串瓷和复合绝缘子进行了冰闪试验研究,考虑了覆冰前染污和均压环(含模拟导线)对冰闪电压的影响。研究表明:在ρSDD=0.1和0.05mg/cm2时,28片XWP2-160绝缘子串的冰闪电压较500kV线路额定运行电压分别约低20.5%和13.1%,在ρSDD=0.025mg/cm2时,约高2.3%;而在ρSDD=0.1和0.05mg/cm2时,FXBW4-500/160绝缘子的冰闪电压较500kV线路额定运行电压分别约低18.7%和12.0%,在ρSDD=0.025mg/cm2时,约高4.3%;在ρSDD和ρNSDD分别为0.1和0.5mg/cm2的重覆冰情况下,不带均压环的冰闪电压比带均压环时约高11.6%。研究结果可给我国线路绝缘子冰闪特性研究和重冰区超高压线路外绝缘配合提供参考。

The insulation performance of insulators will decrease greatly when under the combined conditions of icecovering, snow covering, pollution and high altitudes, hence the flashover characteristics research is very meaningful. The icing flashover characteristics of energized EHV transmission line insulator strings are studied in this paper. The influence of pollution, grading rings （including simulative conductor） are considered. The research results indicate that： 1 ） equipped with the given grading ring and simulative conductor, under the PSDD=0. 1, 0. 05, 0. 025 mg/cm^2 and the heavy icing conditions, the flashover voltages of 28 units XWP2-160 are 20.5 % lower, 13.1% lower and 2.3% higher than the 500 kV transmission line rated phase to earth voltage respectively, those are 18.7% lower, 12.0% lower and 4.3% higher for the FXBW4-500/160 composite insulator respectively; 2） under the pSDD 0. 1 mg/cm^2 and the heavy icing conditions, the flashover voltage without grading ring and simulative conductor is 11.6 % higher than that with grading ring and simulative conductor. The research results can be a reference for the insulator strings icing flashover characteristics tests and external insulation coordination of EHV transmission lines in the heavy icing regions of China.