GIS/GIL中金属微粒污染问题研究进展

Review on Metal Particle Contamination in GIS/GIL

以SF_6或SF_6/N_2混合气体为绝缘介质的GIS/GIL具有大容量、高可靠性和环境友好等特点,特别是在特高压输电及离岸大规模风电输送领域具有巨大应用前景,而GIS/GIL中存在的金属微粒污染问题是提高设备绝缘强度研究中的关键技术难题。首先介绍了GIS/GIL中金属微粒的带电及受力机理研究;然后分析归纳了交流、直流、冲击等不同电压类型与微粒的运动特性和设备绝缘劣化之间的关系和规律;并进一步,对比分析了GIS/GIL中由金属微粒污染引起的典型绝缘故障,即运动微粒引起的气隙击穿和附着绝缘子表面的微粒引起的沿面闪络;此外总结概述了目前主要的微粒抑制措施及其作用机理;最后指出现有GIS/GIL中微粒污染问题研究存在的不足和可能的解决途径。

Using SF6 or SF6/N2 mixed gas as insulation medium, GIS/GIL has the characteristics of large capacity, high reliability, and environmental friendliness. Especially it has a great application prospect in the field of UHV transmission and offshore transmission of large-scale wind power. But the metal particle contamination in GIS/GIL is the key technical problem to improve the equipment insulation strength. We introduce the charged mechanism and stress analysis of a metal particle in GIS/GIL, and analyze the influences of AC, DC or impulse voltages on particle motion and GIS/GIL insulation. Furthermore, we compare the typical insulation faults of GIS/GIL caused by particle contamination, namely the gap breakdown caused by moving particles and surface flashover on insulator adhered by particles. In addition,we summarize the current main particle suppression measures and their mechanisms. Finally, we point out the defects of the existing researches in particle pollution of GIS/GIL and put forward some possible solutions.