Charge Accumulation Characteristics of SF6-Epoxy Interface Under Negative Repetitive Nanosecond Pulses  

作　　者：Shaocong Wu Geng Chen Yuming Shao Hao Xu Xuanning Zhang Yanyu Liang Youping Tu 

机构地区：[1]State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC,North China Electric Power University,Beijing 102206,China

出　　处：《CSEE Journal of Power and Energy Systems》2024年第4期1808-1815,共8页中国电机工程学会电力与能源系统学报（英文）

基　　金：supported in part by the National Natural Science Foundation of China(No.51877080)。

摘　　要：Repetitve nanosecond impulses in gas-insulated metal-enclosed switchgear (GIS) are likely to trigger inside flashover. Interface charges on the spacer in GIS are considered one of the main factors damaging insulation performance and may be induced by overvoltage. For good understanding of insulation failures, accumulation characteristics of charges between SF6 and epoxy spacers under repetitive nanosecond impulses are investigated. It can be found under nanosecond impulses, the charge source in gas volume contributes to interface charge accumulation predominantly. Interface charges will be promoted by impulse number and amplitude. Accumulation processes are analyzed based on runaway electrons mechanism. When impulse amplitude exceeds a threshold value, discharge in the gas volume turns to a runaway mode. A runaway electron leads to the interface charge accumulation. Affected by motion of the runaway electrons, the potential peak gradually moves close to the grounded electrode when impulse amplitude is raised. Meanwhile, increasing impulse number can enhance surface potential. Surface potential will reach saturation eventually. However, memory effect of the repetitive impulse discharge makes the half-peak width of the surface potential at the interface change little. Design of GIS gas-solid insulations can refer to this research.

关 键 词：GIS interface charge repetitive nano-second pulse SF6 

分 类 号：TM73[电气工程—电力系统及自动化]