Citation

Xie Q, Zhu R, Qu W. Dianwang Jishu 2011; 35(3): 221-226.

Copyright

(Copyright © 2011, Neng yuan bu dian li ke xue yan jiu yuan)

DOI

unavailable

PMID

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Abstract

High-power transformers are one of the most important equipment in substations and they are often seriously damaged due to earthquakes. In the violent earthquake occurred on May 12 th, 2008 in Wenchuan, China, a lot of power transformers were seriously damaged. Firstly, the main earthquake damage characteristics of high-power transformers in the Wenchuan earthquake are briefly presented. To analyze the seismic failure mechanism of a certain 500kV high-power transformer that suffered serious damage during Wenchuan earthquake, a finite-element model of transformer-bushing system, in which both beam elements and shell elements are combined, is built. Under the input of three sets of ground motions recorded in Wenchuan earthquake and other two sets of ground motions, the analysis on time-history responses during earthquake is performed by the proposed model, and the seismic responses of the key components in the structure of transformer-bushing system during the earthquake are compared. Analysis results show that bushing structure of high-power transformer is flexible and the bending strength of insulation bushing is inferior, moreover the flexibility of the transformer tank can amplify the seismic responses of the bushings. Thus the high center of gravity, larger slenderness and low strength of the porcelain bushings are main reasons leading to seismic failure of high-power transformer. Bushings are vulnerable components of high-power transformers, so in the aseismatic design of high-power transformer the vulnerability of bushings during earthquake should be taken fully into account.