A ±800 kV high voltage capacitor filled SF

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gas bushing is an important device to realize the electrical connection between a converter transformer and a valve tower. We mainly analyzed the design of the external and internal insulation structure

and discussed the actual operating environment and the characteristics of the voltage and current waveform of converter transformer bushing. Moreover

we designed and analyzed the hollow composite insulator

corona ring and tail end of the bushing. The main insulation structure of bushing was designed by the equal margin method

and simulation and analysis of the multi-physical field were performed by FEM. Meanwhile

a three-dimensional electric field simulation model was set up to calculate and analyze the external insulation pe

rformance of the bushing. The results show that the main insulation of the bushing is fit to the capacitance structure

the maximum axial field strength of the bushing is 0.62 kV·mm

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the hot-spot temperature under the rated operating condition is 85 degree centigrade

and the end of the bushing should be equipped with apple-type corona ring. The insulation distance of the hollow composite insulator is designed as 7 490 mm. The insulation distance of the bushing tail is designed as 3 110 mm. The results can provide a theoretical basis for the design of the external insulation of the converter transformer bushing used in HVDC transmission projects.