应用小磁环加装大磁环抑制GIS中VFTO的试验研究

特快速暂态过电压(very fast transient overvoltage,VFTO)严重威胁到气体绝缘开关设备(gas insulated substation,GIS)和邻近设备的安全运行,在总结前人研究的基础上,文中提出应用小磁环加装大磁环抑制GIS中的VFTO。依托VFTO发生器和真实500 kV GIS组成的试验平台,分别在充电电压为460、500、540、560 kV情况下开展无磁环、40、80 cm小磁环串和80 cm小磁环串加装10 cm大磁环串的一系列对比试验,其中小磁环串是由铁氧体磁性材料构成,大磁环是由纳米晶软磁材料制成。试验数据表明小磁环加装大磁环在所有试验中取得了较好的抑制效果,同时也指出磁环串的长度与抑制作用存在一定的关系。试验结果证实了应用小磁环加装大磁环可增强整体设备对VFTO的抑制效果。

Experimental Study on Suppressing VFTO in GIS with Small and Large Magnetic Rings

To suppress very fast transient overvoltage(VFTO)on gas-insulated switchgea(rGIS),a new approach was proposed by applying small and large magnetic rings.A test platform consisting of a VFTO generator and a real 500 kV GIS was employed to conduct a series of comparative experiments in the absence of magnetic ring,in the presence of 40 and 80 cm(in length)small ring string respectively,and in the presence of 80 cm small ring string together with 10 cm largering string.The charging voltage was 460,500,540 and 560 kV,respectively.The small rings were made of ferrite,and the large rings were made of nanocrystalline.Experimental data shown that combination of small and large ring strings can achieve better suppression effect on VFTO,and the longer the ring string,the better the suppression effect.