Simulation and Experimental Research on S Parameter Characteristics of Partial Discharge UHF Signals in GIS

Study of EM wave propagation characteristics in GIS is meaningful to analyze and localize partial discharge sources. First, based on the finite integration technique, the simulation of S parameters was performed to analyze changes of S parameters with the number of basin-type insulators. Meanwhile, a 252 kV GIS experiment platform was established, where signals from different positions could be obtained by inner sensors. Compared with S parameters calculated from experiments, the simulation results, which showed a good consistency both in waveform and amplitude, were proven to be reasonable. Moreover, a vector network analyzer was used to measure S parameters in different structures of GIS, and simulation models were refined and changed. The results of vector network analyzer were compared with those of simulation which had a good consistency and proved the rationalisation of the simulation conclusion. The results show that the attenuation influence of one insulator can be up to -3 dB, which is in proportion to the number of insulators.