In view of the abnormal voltage fluctuation occurred in a certain ±500 k V converter station

itis found that the abnormal measurement voltage at the remote module of DC voltage transformer is due todefect design in earthing by way of analysis of both structure and design principle of the DC voltagetransformer in the station and of test through setting up DC voltage measurement system. The modificationmeasures for the problem is proposed and implemented

which solves effectively the abnormal voltageissue of DC voltage transformer and also provides a definite reference for the design and selection ofsimilar type of product in the future.