Investigation on polarization characteristics of PD-induced electromagnetic wave leakage in GIS with metal belt

Partial discharge (PD) detection is commonly used in the failure diagnostics of the gas insulated switchgear (GIS) with the basin-type insulator. We recognized that the polarization plays an important role in the PD detection. In this paper, we present both theoretical and experimental investigations on the polarization characteristics of the electromagnetic (EM) wave leakage in GIS with metal belt and the electric field intensity distribution near the GIS aperture. The characteristics of the three electric field components around the aperture are simulated by using software Ansoft HFSS. Experiments are also conducted to verify the theoretical results. Both the simulation and the experiment show that near the aperture the electric field component along the GIS axis is always dominant for the typical configuration under study. For an efficient detection it is therefore advised to use linear antenna sensor placed along the GIS axis.