Optimization Design of Electric Field for Miniaturized GIS Clapboard Insulators
To solve the problem of frequent surface flashover in miniaturized SF6 gas insulated metal-enclosed switchgear(GIS),this paper takes AC 220kV GIS clapboard insulators as the research object,proposes the key technology for electric field design of miniaturized GIS clapboard insulators based on electric field design criteria,analysis of surface flashover accidents,and finite element analysis calculation results of electric field stength distribution.It is found that the current electric field design criteria for GIS insulation components does not consider the impact of two factors on surface insulation.Firstly,the surface flashover voltage in SF6 gas is more dispersed than the gas gap breakdown voltage.Secondly,the very fast transient overvoltage poses a more serious threat to the surface insulation of attached metal particle basin insulators than standard lightning overvoltage.To improve the surface insulation strength of basin insulators,not only the electric field distribution should be optimized to to prevent discharge from developing along the surface,but also the electric field strength in the particle accumulation area should be reduced to improve the fault tolerance of metal particles along the surface.In contrast,basin insulators have better metal particle fault tolerance and are more suitable for switch chambers with more metal particles,while flat insulators are more suitable for busbar chambers with relatively less metal particles.In the electirc field strength verification along the surface,the basin insulator needs to focus on the maximum value of the concave side,while the flat insulator needs to pay attention to the maximum value of the grounding end.In terms of internal insulation verification,both types of insulators need to pay attention to the embedded electrodes surface.
GISclapboard insulatorstructural optimizationelectric field simulationsurface flashover
国家科技期刊平台
NSTL
万方数据
