Study on the Bending Stiffness of Joints Connecting Porcelain Bushings and Flanges in Ultra-High Voltage Electrical Equipment

Abstract

In this study, the equivalent bending stiffness of cement-bonded joints connecting the porcelain bushing and flange in ultra-high voltage (UHV) electrical equipment was investigated. A mechanical bending model of the joint was developed based on its structural features, and a new equation for the equivalent bending stiffness of the joint was proposed. Based on experimental data for nine UHV porcelain bushings, a dimensionless elasticity coefficient for the equivalent bending stiffness equation was determined. Finally, considering two 1000 kV arresters as examples, the bending stiffness was calculated using the equation proposed in this paper and that which is used in China’s seismic code. A comparison of the results shows that the equation proposed in this study is in better agreement with the experimental data. Compared with the code equation, the equation in this paper adopts the expression for the dimensionless coefficient, which can more reasonably reveal the bending mechanism of the joint.