Partial discharge（PD）can reflect the type of different insulation defect in a gas insulated switchgear（GIS）.Different types of PD harm GIS in different degrees

so identification of PD type is important for safe and reliable operation

insulation condition evaluation and rational maintenance strategy of GIS. In order to investigate the features of PD excited by different insulation defect models in GIS

we designed four kinds of typical PD models to simulate the actual insulation defects in GIS. Eight feature parameters are thus extracted from the UHF signals of PD to describe the typical features of each type of PD. A four-class support vector machine classifier is constructed based on support vector machine（SVM）algorithm

and then the PD type is identified by voting method. Experimental results show that the proposed method possesses a high recognition rate and can effectively identify these four types of GIS PDs.