Seismic Response Analysis of 750 kV Transformer's Isolation Structure Under Near-field Ground Motions
The seismic response time history analysis on a 750 kV transformer was conducted by finite element software SAP2000 before and after base isolation under far-field and near-field seismic ground motions.Base shear forces,accelera-tion responses and dynamic response amplification coefficients before and after isolation under under far-field and near-field seismic ground motions were compared.The results indicated that,after isolation,the minimum damping coefficient of the 750 kV transformer will be 0.35,and the minimum acceleration amplification coefficient can be reduced to 43%of the value which before isolation,indicating good damping effect. Compared with far-field motions,750 kV transformers have larger response to near-field ground motions,thereby impacting negatively on structural safety of 750 kV transformers.