Li Tianhui

The propagation characteristics of electro-magnetic (EM) wave in GIS is the theoretical basis of partial discharge diagnosis based on UHF method, which is also the prerequisite and guarantee for better application in the actual detection. As most conventional researches have been concentrated on the GIS structure with single phase in a tank, the propagation characteristics of UHF signal in GIS with three-phase construction have not been elucidated yet. This paper deals with the present status and aims to study the propagation and attenuation of UHF signal in such three-phase construction by using FDTD analysis. Not only the radial component of the signal, but also those in axial direction and that perpendicular to radial direction in different circumferential angles are investigated. The propagation rules of peak to peak value (Vpp) and cumulative energy are profoundly studied.