南方电网超高压公司运行十年以上500 kV线路复合绝缘子运行性能分析及建议

Analysis and Suggestions on the Operational Performance of 500 kV Line Composite Insulators Operating for More Than Ten Years in China Southern Power Grid EHV Company

据统计,截至2019年,南方电网超高压公司运行十年及以上的500 kV线路复合绝缘子将达到18 000余支,为有效掌握此类老旧复合绝缘子运行状态,有必要对其展开专题抽检分析,本研究共抽检超高压公司118支运行10年及以上复合绝缘子,涉及11条线路。试验主要依照DL/T 1000.3-2015进行,并从投运年限、交直流、串型、厂家、线路5个影响因素对试验结果展开分析。结果显示,抽检样品机械性能保持较好,而电气及界面性能劣化严重,从电压性质来看,直流复合绝缘子性能下降较快;从串型影响来看,跳线串比直线串更易老化,双串比单串更易老化;从厂家分布来看,以A、B两个主流厂家为例,A厂家的产品界面老化风险较大,而B厂家的产品的硅橡胶老化更快;从线路分布来看,建议西百甲线老旧绝缘子尽快更换,其余线路差异有待进一步探究。

According to statistics, as of 2019, there will be more than 18 000 composite insulators for 500 kV lines in China Southern Power Grid EHV that have been in operation for ten years or more. To effectively grasp the operating status of such old composite insulators, it is necessary to conduct special random inspections and analysis of them. Total of 118 composite insulators in UHV companies operating for 10 years or more were sampled, involving 11 lines. The test is mainly carried out following DL/T 1000.3-2015, and the test results are analyzed from the five influencing factors of operating life, AC and DC, string type, manufacturer, and line. The results show that the mechanical properties of the samples are maintained better, while the electrical and interface properties are seriously degraded. From the voltage properties, the performance of the DC composite insulators declines faster;from the string type effect, the jumper string is more prone to aging than the straight string. Strings are more prone to aging than single strings;from the perspective of manufacturer distribution, composite insulatorsof company A have a greater risk of interface aging, while the silicone rubber of company B products ages faster;from the perspective of line distribution, it is recommended that the old insulators of Xibaijia line should be replaced as soon as possible, and the differences in the remaining lines need to be further explored.