The DC filed

as the core assembly of the converter station system

is usually composed of multiple pillar equipment and wire connection to form a coupled loop which

due to its highly flexible characteristic

is likely to generate damage under the seismic action. This paper aims to analyze the seismic vulnerability and seismic failure risk of the coupled loop of the pillar equipment in the DC field. The 500 kV coupled loop in the DC field is taken as the object

a refined finite element model is set up

followed by an assessment of its seismic performance. The v

ulnerable curves of the loop equipment are fitted by using the incremental dynamic analysis in conjunction with the nonlinear least squares method. A seismic hazard analysis method based on Monte Carlo sampling is proposed

and the seismic failure risks of key equipment and the overall loop are compared and analyzed. The results show that the root stress response of the support insulators PI

1-2

PI

1-10

and the current transformer CT is relatively high

making them the critical weak equipment in the coupled loop loop. Under the seismic intensity at 0.4g

the failure probability of the loop has already exceeded 50%

and the seismic failure risk of the overall loop is higher than that of individual equipment in the loop. The longer the service time is

the larger the risk difference of the seismic failure is. The corresponding conclusion can provide a theoretical foundation for seismic analysis and the development of measures to enhance the seismic resilience of the loop.