In error calibration test of 1 000 kV AC current transformer（CT）

the test current is as high as 7 200 A

so traditional test methods are no longer applicable. In this study

taking the test of 1 000 kV AC CT calibration in Beijingxi UHV Substation for example

a current-promoting method with high ratio is proposed

including impendence characteristic

reactive power compensation technique

and equipment parameters in the testing

and the data of the test circuit are analyzed. It is revealed that proper reactive power compensation for primary circuit is necessary to complete the error calibration test

and for the current transformer with shield on its inner wall

the maximum impact of the primary conductor’s eccentricity on the error data reaches 27%.