Seismic Interaction between Flexible Conductors and Electrical Substation Equipment

High-voltage flexible conductors are employed to interconnect equipment items in electrical substations located on seismically active regions to carry the electricity from one equipment item to another. They have sufficient slack to allow the conductor to accommodate the relative displacements of the adjacent interconnected equipment under seismic loading. However, additional forces due to the dynamic response of the conductor during severe shaking, and its interaction with the interconnected equipment, could cause additional unpredicted forces resulting in damage or failure of the equipment. This paper presents the results of a project to investigate the dynamic behavior of these conductors and their interaction with the interconnect equipment. The project included performing quasi-static and dynamic tests on one of the most commonly used configurations of these conductors in substations throughout the province of British Columbia in Canada. The results of this investigation demonstrated that there can be significant dynamic force amplification due to dynamic interaction of the flexible conductors with the equipment, and showed that the dynamic effect of these conductors must be considered when evaluating the seismic demand of interconnected equipment.