The analysis on propagation characteristics of electromagnetic waves excited by PD in GIS

The propagation characteristics of the electromagnetic waves excited by partial discharge (PD) in gas insulated substation (GIS) are analyzed in detail in this paper. The results of the analysis show that electromagnetic waves excited by PD propagate in GIS not only in the transverse electric and magnetic mode (TEM), but also in the high order modes-transverse electric (TE) and transverse magnetic(TM), and that the duration of TE and TM is much longer than that of PD impulse in GIS, and that the leakage of electromagnetic waves will increase owing to supporting insulator, which benefits the method of external antenna to receive UHF signal to detect PD in GIS.