交流GIS绝缘子表面亚毫米级金属颗粒的运动和局部放电特性

Motion Characteristics and Partial Discharge Characteristics of Submillimeter Metal Particles on the Surface of AC GIS Spacer

气体绝缘开关设备(gas insulated switchgear,GIS)绝缘子沿面闪络严重威胁供电安全,故障诱因通常归结为GIS绝缘子表面存在的金属颗粒。GIS内金属颗粒尺寸主要是亚毫米级,认识和了解GIS绝缘子表面亚毫米级金属颗粒的局部放电特性和运动特性是分析GIS绝缘子沿面闪络诱因无法回避的问题,但因为研究难度较大,一直以来GIS绝缘子表面亚毫米级金属颗粒的局部放电特性和运动特性尚不被掌握。为此,在前期研究的基础上,建立灵敏度可达0.02pC的综合局放测量系统和运动观测系统,观测获得了GIS绝缘子表面单个、2个、多个亚毫米级金属颗粒的运动特性和局部放电特性,采用有限元法和电磁场理论分析GIS绝缘子表面亚毫米级金属颗粒的运动机制和局部放电机制,并揭示了两者的关联关系,最后讨论特高频法现场检测技术对GIS绝缘子表面亚毫米级金属颗粒的检测失效问题。

The spacer flashover in gas insulated switchgear (GIS) is a serious threat to power supply safety. The cause of failure is usually attributed to the metal particles on the surface of the GIS spacer. The size of the metal particles in the GIS is mainly submillimeter. The partial discharge characteristics and motion characteristics of the particles are the problems that cannot be avoided by analyzing the flashover incentives of GIS spacers. However, due to the difficulty of research, the partial discharge characteristics and motion characteristics of submillimeter metal particles on the surface of GIS spacers have not been grasp. Therefore, based on the previous research, a comprehensive PD measurement system and motion observation system with sensitivity up to 0.02pC were established. The motion characteristics and partial discharge characteristics of single, two and large number submillimeter metal particles on the surface of GIS spacer were obtained. Finite element method and electromagnetic field theory were used to analyze the motion mechanism and partial discharge mechanism of submillimeter metal particles on the surface of GIS spacers, and the relationship between the two was revealed. Finally, the failure problems of ultra-high frequency on-site detection technology on detecting submillimeter metal particles on the surface of spacers in GIS were discussed.