Effect Of GIS Structure On The Performance Of Antenna

Gas insulated switchgear(GIS) has been extensively applied to power system. However, there are several unstable factors in GIS normal operation and partical discharge in one of the most important reasons for GIS failure.Recently, Ultra high frequency(UHF) partial discharge(PD) detection is considered as the main method on GIS failure diagnosis for its high sensitivity and not easily affected by external environment.As the sensor component of the UHF detection,the UHF microstrip antenna directly affects the accuracy and sensitivity.Thus, the design and the performance analysis of the UHF microstrip antenna become a hot issue. This paper focus on figuring how the detecting antenna is affected by the aperture of GIS.The simulation model of a microstrip antennais established using Ansoft HFSS, which is used to detect the UHF signals of GIS. The EM characteristic of the external detecting antenna had been simulated at different locations near the aperture.The verified experiment was conducted.This paper startsfrom thegenerating mechanism and research significance of partial dischargethen the development of PD UHF detection also the fundamental parameters and the design principle of UHF detecting antenna Basing on the GIS structure in practice, the simulation model of a microstrip antennais established using Ansoft HFSS, which is used to detect the UHF signals of GIS. A series of parametersare analyzed at different locations between the detecting antenna and the aperture These parameters include the bandwidth of the UHF microstrip antenna, the resonance frequency, and S11 parameter at the resonance frequency.The experiments had conducted using the Vector Net Analyzer(VNA) to measure the parameters in different testing positions and the experimental results are basically consistent with the simulation results in trend.According to the results of simulation and experiment, conclusion are revealed: with the space increasing between the antenna and the aperturein before and after, the bandwidth of the antenna were mounting, finally stabilized; at the same time the resonance frequency of the antenna is reduced, and finally to 1.5 GHz; the S11 parameter atthe resonance frequency constantly decreases. And with the gap increasing in left and right, bandwidth of the antennaincreases at first, then decreases. So does the resonance frequency.The S11 parameter atthe resonance frequency increases at first, then decreases. With the distance increasing in up and down, the resonance frequency of the antenna is decreased; the bandwidth of the antenna increases at first, then decreases.