Seismic Evaluation and Rehabilitation of Critical Components of Electrical Power Systems

Keywords: Seismic performance.  Rehabilitation.  Electrical power systems.  Substations.  Transformers.  Bushings.  Finite element (FE) analyses.  Mitigation.  Qualitative assessment.

Abstract: The goal of this study was to assess the seismic performance of electrical power substations and develop rehabilitation measures for existing substations using advanced technologies.  A comprehensive study was conducted that included detailed finite element (FE) analyses of different types of transformers and bushings, as well as parameter and experimental studies of the friction pendulum system for use as a possible mitigation approach.  Based on the results of the finite element analysis, simplified models were developed and interaction among transformer-bushing and interconnecting equipment was investigated. Internal packaging of transformers was also evaluated and its seismic performance was qualitatively assessed.  Experimental studies of critical substation components were performed in collaboration with the National Center for Earthquake and Research (NCREE) in Taiwan, which identified important parameters that may impact the response of transformer-bushing systems.  Furthermore, results demonstrate that base isolation using a friction pendulum system is a viable rehabilitation option for substations.