Seismic Performance of 245 kV Current Transformer

Abstract

Substation equipment, whose natural frequencies lie in the normal frequency range of earthquake ground motion, is particularly vulnerable to damage by seismic events. Electric power systems are expected to be functional during and after major earthquakes and it is vital to sustain economic activities and assist recovery, restoration, and reconstruction of the damaged structures and equipment during earthquakes. Current transformer (CT), usually having a narrow long porcelain insulator, is the most vulnerable part subjected to earthquake. This paper evaluates amplifi cation factor in terms of acceleration from the ground to top of the support structure where the current transformer is mounted. Sine sweep tests are conducted on current transformer with support structure to evaluate its dynamic characteristics using shake table tests. The ground motion amplifi cation obtained from fi nite element analysis and shake table tests is compared.