Abstract

Transformer bushing systems have exhibited vulnerability during past earthquakes. Based on past qualification tests, it was found that the seismic performance of transformer bushing systems is improved when the bushings are mounted on a rigid base, as opposed to when mounted on more flexible cover plates of transformers. The addition of flexural stiffeners on the transformer cover plates has been proven to stiffen the base of the bushings and mitigate their seismic vulnerability. In this study, the Performance-Based Earthquake Engineering framework, introduced by the Pacific Earthquake Engineering Research (PEER) center, is used to evaluate in a probabilistic sense the earthquake-induced economic losses of transformer bushing systems both for as-installed and retrofitted mounting conditions. The results are presented in the form of expected losses conditioned on seismic intensity as well as expected annual losses for locations in Southern and Northern California. The results demonstrate the ability of the retrofit approach of adding flexural stiffeners on the transformer cover plates to reduce earthquake-induced economic losses compared to the as-installed conditions/design and further enhance community recovery in the occurrence of a strong seismic event.

摘要

变压器套管系统在过去的地震中表现出脆弱性。根据过去的鉴定测试，发现当套管安装在刚性底座上时，变压器套管系统的抗震性能比安装在更灵活的变压器盖板上时有所改善。事实证明，在变压器盖板上添加弯曲加强筋可以加强套管的底部并减轻其地震脆弱性。在这项研究中，由太平洋地震工程研究 (PEER) 中心引入的基于性能的地震工程框架用于从概率意义上评估变压器套管系统的地震引起的经济损失，包括安装和改造安装使适应。结果以以地震强度为条件的预期损失以及加利福尼亚南部和北部地区的预期年度损失的形式呈现。结果表明，与安装条件/设计相比，在变压器盖板上添加弯曲加强筋的改造方法能够减少地震引起的经济损失，并在发生强烈地震事件时进一步加强社区恢复。