Structural-behavior of supported tubular bus structure in substations under seismic loading

This paper presents an experimental investigation on structural behavior of a temperature member used to interconnect the supported tubular bus structure of 220 kV substation, and the dynamic interaction between the components of a bus insulator substructure under seismic loading. Finite element (FE) analysis was performed to analyze the seismic stress of the supported tubular bus structure. The results of quasi-static experiments showed an elastic deformation characteristic, while the temperature member exhibited a damping ratio of 4-7%, and elastic stiffness of 13.4 N/mm. Compared with the stand-alone configuration, the peak accelerations of insulators connected to the tubular bus through the temperature member were reduced by 10-30%, while the maximum displacements were reduced by 30%. The maximum displacement responses of insulators connected to the tubular bus through clips were roughly the same as those under the stand-alone configuration, while the peak accelerations were reduced by 30-50%. When the ground acceleration reached the value of 6.2 m/s(2), the root stress exceeded the yield strength of the material. Under this condition the insulators may experience fracture or collapse.