运行复合绝缘子芯棒-护套界面性能评估

Evaluation of the Interface Performance Between Mandrel and Sheath of Operated Composite Insulators

芯棒-护套界面性能是表征复合绝缘子运行状态和老化进程的重要对象之一。为准确评估宁夏地区运行复合绝缘子的芯棒-护套界面性能,对宁夏电网运行6年及以上、35 kV~750 kV的33个厂家批次复合绝缘子进行剖检试验和带护套芯棒水扩散试验,并对水扩散试验结果不同的试品做傅里叶红外光谱分析。结果表明,在密封性能良好的情况下,有23个厂家批次复合绝缘子的芯棒-护套界面粘接性下降、耐水解及耐湿热老化性能下降;相同运行环境下复合绝缘子芯棒-护套界面的老化进程与伞裙表面的老化进程不一致;复合绝缘子芯棒-护套界面性能劣化与其运行年限有直接关系。评估结果可为复合绝缘子运维检修提供建议。

Interface performance between mandrel and sheath is one of the most important objects to characterize the operating state and aging process of composite insulators. In order to accurately evaluate the mandrel-sheath interface performance of the operated composite insulators in Ningxia, profile test and water diffusion test of the mandrel-sheath interface were carried out for 33 batches of composite insulators in Ningxia power grid that had been in operation for 6 years or more, and samples with different water diffusion test results were analyzed by FTIR. The results showed that under the condition of good sealing performance, there were 23 batches of composite insulators whose adhesion, hydrolysis resistance and damp-heat aging resistance of mandrel-sheath interface had decreased. The aging process of the mandrel-sheath interface was inconsistent with that of the skirt surface under the same operating environment. The degradation of interface performance between composite insulators’ mandrel and sheath was influenced directly to its operating life. The evaluation results could provide suggestions for the operation and maintenance of composite insulators.