Seismic Behavior of UHV Insulator Systems: Isolated vs. Interconnected Cases

Slender porcelain post-type equipment remains predominant in China’s high-voltage grids, while interconnected units exhibit heightened seismic vulnerability due to their unique structural and material properties. This study advances seismic performance research by conducting shake-table tests on UHV insulator units and their interconnected configurations, systematically analyzing structural responses to ground motion types, excitation directions, and conductor lengths. Test results confirm that: (1) Stronger earthquakes amplify the adverse effects of conductor interconnection on seismic resistance, with interconnection length effects being excitation-directiondependent; (2) Seismic wave combinations don’t necessarily exceed unidirectional excitations-unidirectional scenarios must be included in verification tests; (3) UHV equipment tests should evaluate stresses across all bushing sections to prevent non-root failures; (4) Manufacturing/construction quality critically determines seismic performance. The findings provide theoretical support for optimizing seismic design, refining test methods, and improving manufacturing processes in electrical equipment circuit systems.