Seismic Interaction of Interconnected Electrical Substation Equipment

This paper investigates experimentally the dynamic interaction between components of electrical substation equipment interconnected by rigid bus conductors. Specific tests conducted in this study were (1) quasi-static tests of three different types of rigid bus with spring connectors; (2) quasi-static tests of one rigid bus slider; and (3) shake table tests of five different pairs of generic substation equipment specimens interconnected by three different rigid bus assemblies. All connectors tested exhibited stable hysteretic behavior with various degrees of energy dissipation capacity. The spring connectors dissipate energy through yielding and generated the highest forces among the connector tested and generally caused an amplification of the dynamic response of one of the interconnected equipment components. The bus slider dissipated energy through friction and generated lower forces than those of the spring connectors. Its high damping capacity, however, systematically reduced the dynamic response of interconnected equipment components. Finally, a special seismic connector that incorporates three flexural vertical aluminum cables generated the lowest forces. Its minimal damping capacity, however, resulted in higher equipment dynamic response than with the bus slider.