GIS中快速暂态过电压VFTO的抑制研究进展

Research Progress in Suppression of Fast Transient Overvoltage VFTO in GIS

气体绝缘变电站GIS中的隔离开关在分合闸时,会产生快速暂态过电压VFTO,对GIS本身及邻近设备将造成极大危害。综述了国内外现有抑制VFTO的研究现状。从抑制VFTO的产生、改造GIS内部结构及抑制VFTO沿输电路径传播3个方面,概要总结了各抑制方法的优势及存在的问题。提出了抑制VFTO需要深化的研究内容:研制能精准控制开关合闸时间的成套设备,怎么样控制电弧击穿导通的时间,通过微机系统综合控制实现精准相位合闸;探索场路论结合的方式准确仿真加装阻尼母线前后VFTO的变化,建立阻尼母线抑制VFTO的特性参数关系;磁环抑制VFTO的理论,量化分析磁环的物理尺寸及磁材料特性参数对抑制效果的影响,在此基础上进而研究半圆卡扣式磁环对抑制VFTO的影响,以便后续在运GIS的改造,最后还需进一步研究如何解决磁饱和增加磁损耗增强抑制效果。

The disconnecting switch in a gas-insulated substation GIS generates a fast transient overvoltage VFTO when it breaks and closes,which will bring great harm to the GIS itself and the neighboring equipment.This paper reviews the current status of existing research on VFTO suppression at home and abroad.The advantages and problems of each suppression method are summarized from three aspects:suppression of VFTO generation,modification of GIS internal structure and suppression of VFTO propagation along the transmission path.The research contents that need to be deepened to suppress VFTO are proposed as follows:developing complete sets of equipment that can accurately control the closing time of the switch;how to control the time of arc breakdown conduction and to realize accurate phase closing through integrated control of microcomputer system;exploring the combination of field and path theory to accurately simulate the change of VFTO before and after adding damping bus,and establishing the characteristic parameter relationship of damping bus to suppress VFTO;by magnetic ring to suppress VFTO theory,quantitatively analyzing the physical size of the magnetic ring and the influence of the magnetic material characteristics parameters on the suppression effect.Thereby,the influence of the semi-circular snap-on magnetic ring on the suppression of VFTO for the subsequent transformation of the GIS in operation is studied.Finally,how to solve the magnetic saturation to increase the magnetic loss to enhance the suppression effect needs to be further researched.