Abstract:With the rapid development of power system, the demand for electrical energy of enterprises and users is increasing. In order to meet the needs of enterprises and users, the production and distribution of electric energy must be increased. In recent years, the GIS substation has been built a lot by virtue of its great advantages. At the same time, the verification of the GIS current transformer is also added as one of the energy metering devices. The verification of GIS current transformer has become a hot topic. This paper mainly introduces the testing principle of three kinds of GIS current transformer, that is, comparison method, low voltage extrapolation method and load simulation extrapolation method. Under the same condition in the field, the test data of three kinds of testing principle and equipment are compared, and the advantages and disadvantages of the equipment based on the three different principles are compared. Finally, the trend of current transformer error detection is proposed.