Experimental seismic evaluation of base-isolated transformers

Abstract

Experimental evaluations of seismic performance of substation equipment such as transformers, bushings, and disconnect switches have gained importance over the past decade. This paper presents the results of shake table tests performed on a transformer model with a bushing mounted on the top of it. The objective is to compare the response of fixed-based transformer to the base-isolated case. It is observed that considerable inertia reduction is attained at different levels along the height of the transformer within the displacement limits of the bearings. Furthermore, the bushing inertia forces are also reduced supporting the effectiveness of the isolation system for secondary systems as well.