特高压GIS变电站VFTO仿真计算研究

VFTO Simulation Study for UHV GIS Substation

气体绝缘开关设备(gas insulated switchgear,GIS)中的隔离开关投切空载短母线时会产生陡波前、高幅值的特快速瞬态过电压(very fast transient overvoltage,VFTO),对GIS及其连接的设备产生危害,严重影响设备的安全运行。通过电磁暂态程序(electro-magnetic transient program,EMTP),针对我国"皖电东送"工程某特高压变电站开展了仿真研究,并对影响VFTO的几种因素进行分析。结果表明,母线拓扑结构和残余电荷电压对VFTO影响较大,通过合理设计隔离开关可减小残余电荷电压水平,从而显著降低变电站VFTO水平。

Very fast transient overvoltage （VFTO） with steep wave-front and high amplitude, is generated during the switching of disconnector with no-load short busbar in gas insulated switchgear （GIS）, which is harm to GIS and the connected equipments, as well as seriously affect the safety operation of these equipments. Simulation study of VFTO in UHV GIS substation in Anhui-to-east power transfer project was carried out with using the tool of Electro-magnetic Transient Program （ EMTP）, and several influencing factors on VFTO were studied as well. The results show that both the topological structure of busbar and the trapped charge voltage have great influence on the VFTO. Through the rational design of disconnector, the trapped charge voltage can be limited to a comparatively low value, which consequently leads to the reduction of the level of VFFO in GIS substation.