Diagnosis and analysis for a typical defect of partial discharge in GIS

GIS equipment is widely used in electric power system, however, partial discharge affect the normal operation of the equipment. The paper introduces the principle of ultra-high frequency and acoustic emission partial discharge living detection methods and SF6 gas decomposition detection. And this pa per introduces typical defect cases of partial discharge in GIS equipment using different living detection method, combined with on-line monitoring. The living detection result is verified correctly after dismantlement, and analyses the reason of partial discharge. The final conclusion is that combined with ultra-high frequency on-line monitoring and a variety of living detection methods can improve the detection efficiency for insulation defects such as partial discharge in GIS equipment.