A novel approach for seismic risk assessment of porcelain cylindrical electrical equipment

Traditional seismic risk assessment approaches have been applied to different types of electrical equipment in substations. Recently, some of the authors have proposed a novel seismic risk assessment approach for new and existing structures, which is based on idea to control the record-to-record variability rather than reduce it by scaling the ground motion signals. This paper introduces the framework into seismic risk assessment of typical porcelain cylindrical electrical equipment (PCEE). Accordingly, two different sets of records are selected using the algorithm proposed in the framework to assess the risk of three pieces of PCEE selected. The selected PCEE exhibits diverse structural characteristics, providing a robust basis to evaluate the effectiveness of the proposed framework across varying configurations and dimensional settings. Besides, the influence of the dispersion of limit states (LSs) on the fragility and risk of the PCEE is also investigated. The results indicate that the consistent fragility curves and risk results induced by the two record sets verify the effectiveness of the framework when applied to PCEE. Obvious differences in failure probability are observed due to the dispersion of limit states (LSs), exhibiting a “0-positive-0-negative-0” pattern as peak ground acceleration increases. Overall, the seismic risk of the PCEE increases with greater LS dispersion. Moreover, there is minimal variation in structural risk between using Normal or Weibull distributions to model LS dispersion. Targeting fragility and risk, adopting a one-piece design for PCEE insulators proves more advantageous for structural safety than using an assembled construction with flanged joints.