Through on-site testing on GIS

transformer and other electric equipment

the partial discharge（PD） caused by equipment internal defects can be detected. Because of the differences among the GIS bushing structure

material and GIS ontology

the methods which to detect and locate GIS ontology don’t apply to GIS bushing. In order to find the bushing’s internal insulation defects

this paper analyzes the suspended discharge defects in the GIS bushing of some 220 kV equipment in a 500 kV substation based on partial discharge detection with UHF method

defect pattern recognition

discharge position and dissolution test analysis. According to the figures of phase resolved pulse sequence（PRPS） and phase resolved partial discharge（PRPD）

the defect types are recognized. The discharge positioning process is stated based on time leading method

point plane method and triangulation method and is judged combining with other testing means. In the end

this paper finds out the reason of bushing’s internal discharge and the reason is too much glue between the pole flange junction and the bushing flange junction which leads to suspended discharge. Through the study

this paper validates the correctness of defect recognition

the accuracy of discharge position and the effectiveness and complementary of integrated application of various charged detection technologies.