Development and its Application of D.C. bushings of valve hall side of converter transformer

One ±400kV-±800kV D.C. bushings of valve hall side of converter transformer is developed based on the using property and technical demanding of converter transformer of Ultra-high voltage direct-current (UHVDC) Power transmission project from Jinping to Sunan and Hami to Zhengzhou. The Dimension and structure and technical characteristic of the bushings is introduced in this paper. The distribution map of the bushings of for electric field of alternating current(AC) and direct-current (DC) are given in details. The result of type tests and margin tests based on the ISO standard of bushings for D.C. application are presented. The application and running of ±400kV-±800kV D.C. bushings are also introduced on the converter transformer and valve hall of UHVDC Power transmission project from Jinping to Sunan and Hami to Zhengzhou.