1. Dielectric Surface Flashover under Long-Term Repetitive Microsecond Pulses in Compressed Gas Environment
- Author
-
Wang Zhengwen, C. Liu, Tianyu Lin, Lu Zhijian, Wei Peng, Yongpeng Zhang, and Lanjun Yang
- Subjects
Technology ,Materials science ,Insulator (electricity) ,02 engineering and technology ,Dielectric ,Radiation ,01 natural sciences ,Article ,accumulation effect ,0103 physical sciences ,Empirical formula ,Arc flash ,General Materials Science ,microsecond repetitive pulses ,flashover characteristics ,Composite material ,stage insulator ,010302 applied physics ,Microscopy ,QC120-168.85 ,QH201-278.5 ,021001 nanoscience & nanotechnology ,Engineering (General). Civil engineering (General) ,TK1-9971 ,flashover path ,Microsecond ,Descriptive and experimental mechanics ,Electrode ,Electrical engineering. Electronics. Nuclear engineering ,TA1-2040 ,0210 nano-technology ,Microwave - Abstract
As a key component of a high-power microwave (HPM) system, a multi-gap gas switch (MGS) has recently developed insulation failure due to surface flashover. Although design criteria for surface insulation have been put forward, it is still not clear how the insulation in this case deteriorated under long-term repetitive microsecond pulses (RMPs). In this paper, flashover experiments under RMPs were carried out on various dielectric surfaces between parallel-plane electrodes in SF6 and air atmospheres, respectively. Based on tests of the surface insulation lifetime (SIL), an empirical formula for SIL prediction is proposed with variations of insulator work coefficient λ, which is a more suitable parameter to characterize SIL under RMPs. Due of the accumulation effect, the relationship between E/p and ptdelay varies with the pulse repetitive frequency (PRF) and SIL recovery capability decreases with an increase in PRF and surface deterioration is exacerbated during successive flashovers. It is concluded that the flashover path plays a crucial role in surface insulation performance under RMPs due to the photoemission induced by ultraviolet (UV) radiation, signifying the necessity of reducing surface paths in future designs as well as the improvement of surface insulation.
- Published
- 2021