GIS盆式绝缘子对超高频电磁波衰减的仿真研究

摘要

时域有限差分算法对GIS内局放激发超高频电磁波信号经盆式绝缘子的衰减特性进行仿真研究.首先研究了盆式绝缘子对超高频电磁波电场信号强度的衰减作用,指出绝缘子对在GIS腔体内传播的超高频电磁破电场强度衰减较小,对通过绝缘子泄漏到GIS腔体外的超高频电磁波电场强度衰减较大.然后研究了经绝缘子衰减后超高频电磁波电场信号增益的幅频特性,指出在GIS腔体内绝缘子对超高频电磁波的衰减集中在1000 MHz以上,而从绝缘子处泄漏到GIS腔体外的电磁波信号其衰减集中在1500 MHz以下和3000 MHz以上频率.%In this paper, Finite Difference Time Domain ( FDTD) method was used to simulate the attenuation effects of disk-type spacer in GIS on PD-induced UHF electromagnetic wave. Firstly, the attenuation effects of disk-type spacer on p-p value of PD-induced electromagnetic wave were evaluated. Simulating results show that p-p value of PD-induced electromagnetic wave is slightly attenuated when it transmits through the spacer inside the GIS chamber, while it is significantly attenuated when it leaks out of the chamber through the spacer. Secondly, the amplitude-frequency characteristics of E-filed gain when UHF electromagnetic wave transmits though the spacer was studied. Simulating results show that the attenuation frequency is mostly higher than 1 000 MHz when UHF signal transmits through the spacer inside the GIS chamber, while it is mostly in the span between 1 500 MHz and 3 000 MHz.