Propagation characteristics of GIS PD, signals by UWB PD detection system using dual UHF band method

It is widely known that the ultra high frequency (UHF) method that detects the electromagnetic wave of the PD pulses in the gas insulated space is one of the most competitive methods for its high sensitivity. From the above point of view, this paper describes the propagation characteristics of GIS PD signals measured with ultra wide band (UWB) GIS PD detecting system in which PD signals are detected into the dual UHF band. The UWB PD detection system consists of the UWB UHF coupler, the UWB low noise amplifier (LNA) and the oscilloscope. The dual bands for PD signals are 0.5-2 GHz (full band) and 1-2 GHz (high band). As a result, propagation characteristics of GIS PD signals were measured in the mock-up GIS bus and it was found that the propagation characteristics of the high band showed a better result in accordance with the internal configuration of the GIS bus than those of the full band.