Replacement Scheme and Insulation Performance Analysis of Bushing on Network Dide of 800kV Converter Transformer

Converter transformer is the key equipment in DC project, and the network-side bushing is the most critical component. In recent years, there have been many serious incidents in China, such as porcelain bushing bursting and transformer burning, which are called “firecrackers on the oil tank”. In order to eliminate the potential safety hazard of the oil-filled bushing, it is decided to replace the oil-filled bushing on the side of the rheological network. In this paper, based on the scheme of replacing the 500kV oil-filled bushing of converter transformer at ±800kV UHV Tianshan Converter Station with epoxy resin impregnated paper bushing (dry bushing) with high structural strength and good anti-explosion and flame resistance, the selection principle of electrical performance parameters and installation size of the bushing are analyzed. The axisymmetric finite element model of casing is established by finite element software, and the electric field of casing is simulated. The process steps of casing replacement are described in detail. This paper can be used as a guide for the replacement of similar casing.