Full-Scale Testing on Seismic Performance of Surge Arrester with Retrofitted Composite Insulators

Abstract

In electrical substations, glass-fibre reinforced polymer (GFRP) insulators provide an alternative to porcelain insulators for better seismic performance. The bonded connection between the composite tube and the metal end fitting is a weak link under earthquake actions, and the failure risk of ultra-high voltage (UHV) substation equipment with GFRP composite insulators can be considerable in places with high seismicity. This study solved the problem by retrofitting and experimentally qualifying the seismic performance of surge arresters made of composite insulators. To ensure safety under a bending moment corresponding to the seismic demand, the bonded sleeve joint between the tube and end fitting was retrofitted by shear stiffeners and higher strength end fitting. A full-scale shaking table test was carried out to verify the performance of the retrofitted surge arrester, and the seismic responses to increasing earthquake actions were analyzed. The specimens in this study were full-scale, had the largest dimensions among substation equipment of the same type, and were subjected to an extremely high earthquake action of 0.5 g; therefore, the seismic testing results produced in this study can serve as an important reference for the industry.