The Study On Large Substation Seismic Vulnerability Considering The Interaction Of Structure And Electric Equipment

As an important part of the whole power system, substation once suffered earthquake damage will cause the entire power system can not run normally, which will not only cause serious secondary disasters and heavy economic losses, but also affects the smooth progress of relief work smoothly. At present, the research for earthquake disasters of the power system have been strengthened both at home and abroad, but substation seismic vulnerability research is still in its beginning stage. There are many issues which need further study.According to the actual substation project, a three-dimensional dynamic analysis model is established considering interaction of the main structure and the electrical equipment. The influence of the different placing forms of electrical equipment and the different quality of electrical equipment- main structure to electrical equipment for vibration cycle and the vibration type feature of the substation are inspected. Compari-son was made between the current design method of not considering the interaction of electric equipment and main structure calculation model analysis results and using the method above. The results showed that longitudinal stiffness of the main structure of the substation has great difference with the transverse stiffness, the torsional stiffness is small and the torsion effect is remarkable. Besides, the different place form of equipment and the different quality of the equipment - the main structure has the influence of different level for the vibration cycle and vibration mode of substation. So the calculation model considering the interaction of the main structure- equipment is capable of reflecting the dynamic characteristics of substation more real.The dynamic characteristics of transformer substation is obtained. 100 practical seismic records of different epicentral distance and magnitude is chosen and the biggest layers structural displacement Angle is chosen as seismic demand parameters. Under the condition of different placing forms of electrical equipment and the different quality of electrical equipment - main structure, considering the ground vibration variability, the nonlinear time-history analysis for substation is done. Through the earthquake needs analysis, establish seismic demand model is established. Finally, the seismic vulnerabil-ity curve for substation is obtained. The results showed that, with the increase of the peak ground acceleration PGA, the failure probability of the four destruction states ,mild damage, moderate damage, severely damaged and collapsed are gradually increasing. Namely the vulnerability of substation increased. With the gradually increasing of quality ratio, the failure probability of destruction states for the same ground peak accelerations PGA has a trend of gradually increase. So when knowing the peak ground acceleration, the form of equipment place, the quality ratio of the equipment - the main structure, we can evaluation the failure probability of substation under earthquake from the seismic vulnerability curve.