Research on Insulation Structure Design of 550kV Gas-Insulated Composite Bushing

This paper presents a comprehensive study on the insulation structure design of 550 kV SF6 gas-insulated composite bushings. The research focuses on optimizing both the internal and external insulation structures to enhance the operational reliability and performance of the bushings. Utilizing finite element method (FEM), the electric field distribution within the bushing is simulated, and key parameters such as the height of the grounding shield, the distance between the shield and the conductor rod, and the corner radius of the shield are adjusted. Additionally, the external grading rings are optimized to control the electric field distribution on the bushing surface. The results demonstrate that the maximum electric field strength at critical locations meets the design requirements, ensuring long-term stable operation of extra-high voltage (EHV) switchgear. The findings are of significant engineering importance for the design and application of EHV bushings.