The ±1 100 kV Changji-Guquan UHV DC transmission project is the very transmission project in the world having the highest voltage level

the largest transmission capacity

and the longest transmission distance.In this study

the applied AC voltage withstand test with partial discharge（PD）measurement in field for Changji converter station’s UHV converter transformer was studied.The test method

test arrangement

test equipment

test parameters

environment field check

and test result were analyzed to verify the feasibility of using the hoisting-free and equipped insulation test platform to conduct the test in the valve hall.It was proposed that the minimum clearance of the electric field calibration air in the valve hall should be no less than 7.5 m.The finally measured PD quantity in this test was less than 150 pC.The test method and test result in this study may be provided as reference for the relevant tests performing in valve hall.