Seismic Response of High Voltage Electrical Transformer–Bushing Systems

High voltage porcelain bushings mounted on transformers have shown vulnerability during past earthquakes. This is contrary to the generally good performance observed during shake table qualification testing of bushings anchored to a rigid base. The seismic vulnerability of porcelain bushings might be caused by the flexibility of transformer tanks and of bushing attachments. Current seismic qualification guidelines consider an amplification …