With the development of country economy, the demand for reliability of power supply is gradually increasing. The insulation performance of high-voltage bushing is widely concerned as one of the main components of transformer. In this paper, aiming at improving the performance of the 500 kV GOE oil-immersed bushing, the electric field simulation model of the bushing is established by using the finite element method. The bushing electric field distribution under certain conditions is analyzed, considering the influence of the capacitance plate thickness on the electric field distribution in the core, and the electric field distribution intensity on the surface of shield electrode under different electrode radius and ascending flanged base diameter. As a reference standard, the maximum field-strength of the bushing is extracted. And following the standard, the structure of shield electrode is optimized by combining the influence of the thickness of the capacitor core plate and the radius of the shield electrode on the field-strength. The results have guiding significance for engineering application.

electric field simulation analysis,insulation structure optimization,oil-immersed bushing,plate thickness