Seismic performance of the coupled suspended filter capacitor in high intensity seismic fortification region is significant for UHVDC converter substations.Based on a suspended UHVDC filter coupling loop

the finite element models in the standalone and coupled states were established and seismic responses of the two modes were investigated.The results indicated that

the maximum value of the threedirection acceleration peak of each layer of the suspended filter capacitor is reduced in the coupled states

compared with that of the standalone

and the maximum internal force response was slightly increased.The diagram of the peak displacement of the layers presented as the crescent shape and changed seriously in the coupled plane.The post electrical equipment could increase the lateral stiffness in the coupling plane of the suspended filter capacitor and the acceleration response is more likely to be affected by the low frequency components

which are below 1 Hz.The amplific ation effects of the post electric al equipment on the horizontal displacement responses of the filter could be ignored

which means that the distance between different equipment do not need to be changed after considering the interconnecting effects.The coupling effect of the post electrical equipment suppresses the occurrence of elastic rebound while increases the internal force response of the outer oblique insulators rapidly.Moreover

it is necessary to improve the strength of the fittings of the V-shaped intersection of the outer oblique insulators.