Research on the Attenuation Characteristics of UHF Electromagnetic Waves inside UHV GIS Switchgear

By monitoring the ultra-high frequency electromagnetic wave signals inside the UHV gas insulated switchgear, it is possible to promptly detect partial discharge defects generated within the equipment. However, the ultra-high frequency electromagnetic wave signals will experience varying degrees of attenuation when propagated inside the GIS. If the online monitoring sensor arrangement is not reasonable, it may not be sufficient to detect the attenuated ultra-high frequency electromagnetic wave signals. Especially for switchgear with numerous internal components, such as circuit breakers and isolation switch chambers, the attenuation process of ultra-high frequency electromagnetic waves is more complex and cannot be calculated through simple empirical formulas. Therefore, it is necessary to conduct research on the attenuation characteristics of ultra-high frequency electromagnetic waves inside UHV switchgear. This article established a three-dimensional proportional electromagnetic field simulation model based on the actual structural dimensions of UHV switchgear, and calculated and analyzed the attenuation characteristics of ultra-high frequency electromagnetic wave signals within the frequency range of $300\mathrm{MHz}1500\mathrm{MHz}$. The conclusions drawn could provide theoretical support for the selection of monitoring sensors for ultrahigh voltage GIS online.