Research on the Influence of Coupling Effect Between Steel Valve Hall Structure and Equipment on the Seismic Response of 800 kV Wall Bushing

Taking the 800 kV wall bushing of a typical ultra-high voltage valve hall as the research object, seven finite element models were established considering different coupling modes between the 800 kV bushing and the steel structure valve hall, valve tower, 400 kV wall bushing, and firewall. The seismic response laws of the wall bushing and its end plates were studied. The research results showed that the stress amplitude of end plates of the 800 kV wall bushing increaseed by 21.7% to 26.6%, while the lateral acceleration amplitude increased by 20.5% to 31.1%, after considering the coupling effect with the steel structure valve hall, firewall, and 400 kV wall bushing. The stress amplitude of the outer casing pipe was relatively larger, approximately 1.06-1.17 times that of the inner casing pipe. The coupling effect between the valve hall structure and the equipment had increased the stress amplitude of the inner casing pipe by 10.3-11.9%, while there was no significant impact on the stress of the outer casing pipe (with a maximum difference of only 0.62%). The coupling effect of structural equipment significantly increased the relative displacement between the conductive rod and the inner wall of the casing pipe, increasing the lateral relative displacement by 20.6-63.4% and the longitudinal relative displacement by 38.5-42.8%. Therefore, in the design, selection, and strength verification of wall bushings, the adverse effects of the coupling effect between the steel structure valve hall and the equipment should be comprehensively considered in order to obtain more scientific and accurate conclusions.