Impact of Gas Insulated Switchgear Structure on Partial Discharge Electromagnetic Wave Propagation

Different components of the Gas Insulated Switchgear (GIS) structure can have impacts on Partial Discharge (PD) Electromagnetic (EM) wave propagation. This is important in selecting PD sensor placement to provide an optimum sensitivity in its measurement and to provide accurate localization of PD sources within the GIS. In this paper, impact of the PD sensor direction angle (with respect to a PD source), on PD EM wave’s propagation characteristics is investigated. To quantify and analyze the calculation results, the first peak of related electric field and the signal s power over the two frequency ranges (0.3-2 GHz and 0.3-3 GHz) are recorded. The impacts of different enclosure diameters, different types of spacers, and various circuit breaker contact gap distances (under different voltage levels) on this wave propagation are studied. Additionally, the two standard GIS busbar profiles, named: L-shape and T-shape; are discussed in this paper. The results of this study shows that the attenuation degree of the measured PD EM waves is strongly influenced by the busbar dimensions and its components configurations. The GIS busbar designer can employ these results to select the proper PD sensors and their installation locations.