Seismic performance analysis of a UHV converter transformer bushing system

A finite element model of a UHV converter transformer was established to study how the seismic response of bushings and the amplification effect of the transformer tank on its bushing, one AC bushing, and two DC bushings. The frequency of DC bushings was smaller than that of the AC bushing, with the first four frequencies being all the modes of DC bushings. The results of stress and displacement response showed that the AC bushing was more affected by horizontal seismic action, while the two DC bushings were more sensitive to Z-direction seismic excitation. Besides, the stress amplification factor was used to evaluate the seismic amplification effect of the transformer tank on bushings.