复合绝缘子的5000h多因素试验及长期性能评价

5 000 h Multi-stress Test Procedure for Silicone Rubber Composite Insulators and Its Applications in Long-term Performance Evaluation

随着特高压复合绝缘子的大规模应用和超高压复合绝缘子运行年限的不断增长,复合绝缘子的现场老化问题与长期性能评价方法成为亟待研究的问题。为此,根据对现场运行条件下硅橡胶复合绝缘子积污和憎水性变化过程的研究,在IEC多因素试验方法的基础上,加入了硅藻土污秽成分并调整了老化因素的时间安排,提出了复合绝缘子的"清华5 000h多因素试验方法"。在该试验方法下进行了5轮次的5 000h多因素老化试验后,成功模拟了复合绝缘子表面污秽积累过程和表面憎水性的丧失与恢复过程,重现了不同复合绝缘子憎水性下降、起痕与电蚀损、过流跳闸等现场老化失效模式。不同配方和配置的复合绝缘子的老化结果表明,硅橡胶复合绝缘子需要同时达到耐起痕和蚀损性能强、憎水性良好、爬电比距足够的要求,才能保证其在正常运行条件下的长期可靠性。

With increasing applications of UHV and EHV silicone rubber composite insulators in China,aging problem and long-term performance evaluation of silicone rubber insulators（SR insulators） become urgent issues to be studied.We discussed dynamic contamination and hydrophobicity changing process in service condition,and proposed an optimal 5 000 h multi-stress test method,THU 5 000 h test procedure,based on proper modifications made to the IEC 5 000 h test method.We conducted five tests under the new procedure,in which the pollution and hydrophobicity changing processes were simulated successfully,and revealed the onsite ageing phenomena including hydrophobicity reduction,tracking and erosion,and over current.Moreover,we discussed the long-term performance and reliability of silicone rubber insulators.It is revealed that the silicone rubber insulators should meet the requirements of erosion resistance,hydrophobicity and creepage distance to ensure the long-term reliability in the field.