Study on frequency spectra of partial discharge according to defects and couplers

This paper described the differences of partial discharge spectra which were measured according to types of defects and couplers. The partial discharge spectra which were occurred in three type defects were measured in the GIS chamber with a log periodic coupler and partial discharge spectra which were occurred in surface discharge defects were measured in transformer chamber with three different folded dipole couplers. The characteristics of spectra due to defects in GIS chamber had high intensity frequency zone and low intensity frequency zone. As the spectra of surface discharge in transformer chamber were measured with three folded dipole couplers these characteristics of spectra had different frequencies characteristics. And these spectra also had different frequencies characteristics according to distance between positions of couplers and partial discharge location.