Considering seismic interaction effects in designing steel supporting structure for surge arrester

Porcelain surge arrester is common in electrical substation and is vulnerable in earthquakes. In most cases, surge arrester needs to be mounted on the top of a steel supporting structure. The seismic response behaviors and failure modes of a steel supporting structure - surge arrester system are critical for the safety and reliability of substations. This paper aims at investigating such interaction effects on the seismic responses of surge arrester. Porcelain surge arresters in 220 kV, 500 kV, 750 kV and 1000 kV are considered in this study. Earthquake induced flexural stress and displacement are identified as key response parameters of a steel supporting structure - surge arrester system based on a full-scale test of 1000 kV porcelain surge arrester. Analytical model of the system was then developed and verified by full-scale shaking table test. The effects of supporting structure on the bending moment and displacement responses are then investigated through time history analysis, modal analysis and a parametric study. Finally, a structural design procedure is proposed for selecting suitable value of flexural rigidity of the steel supporting structure.