In order to study the advantages and disadvantages of detecting the partial discharge of in GIS（gas insulated switchgear） by the pulse current method

the ultrasonic method and the UHF method

using 220 kV GIS establish a set of GIS partial discharge detection platform.Application of the three methods

the three kinds of typical defects of the high voltage conductor tip

the ground electrode tip and the suspended tip are detected

access to a large number of experimental data and mappings.The test results show that the sensitivity of the pulse current method is higher

but the ability of anti-interference is lower

and field application has a certain limitation;with regard to the ultrasonic method

the sensitivity is lower

but the ability of anti-interference is higher

and both the ability of anti-interference and the sensitivity of the ultrahigh frequency is high

so it is suitable for the field detection.On the whole

many testing methods need to cooperate to comprehensive confirmation.