Influence of supporting frame on seismic performance of 1100-kV UHV-GIS bushing

摘要

This paper evaluates the influence of supporting frames on the seismic performance of an ultra-high voltage (UHV) gas insulated switchgear (GIS) bushing. Shaking table tests were carried out on a full-size UHV-GIS bushing mounted on two identical supporting frames except for their braces and joints. Finite element analyses were carried out on the joints' stiffness of the two frames, and seismic analyses on the bushing-supporting frame systems were conducted. Afterwards, parametric analyses on the joints' rotational and axial stiffness in the frames were carried out. The results indicated that the dynamic properties of the supporting frames affect the seismic performance of the bushing. After retrofitting, the amplification effects of the frame were reduced, and the seismic performance of the system improved. Moreover, the frame mainly amplified the acceleration response spectra near the fundamental frequency of the frame itself. The supplemented braces made greater contributions to reduce the seismic responses of the GIS bushiung, and increasing the joints' stiffness could reduce the severity of seismic responses on a bushing. (C) 2019 Elsevier Ltd. All rights reserved.