Parameter study of load combinations in seismic design for UHV transformation devices

For UHV electrical devices, owing to their importance, uniqueness, and relatively high safety margin requirements, their seismic performance has become the focus of engineer´s attention. Such devices are prone to generate resonance under the effects of earthquake, which will lead to damage to them. Moreover, most of the major devices have exceed the application scope of seismic design criteria, and values of related parameters of seismic design are different based on different criteria. Therefore, it is necessary that study on relevant problems existing in the seismic design of UHV transformation devices is carried out. In this study, the related clauses in Code for seismic design of buildings (GB50011-2001), Code for design of seismic of electrical installations (GB50260-96) and IEEE Recommended Practice for Seismic Design of Substations (IEEE Std 693) were compared and analyzed, and at the same time, the parameters of load combinations in the seismic design (i.e. every subentry coefficient and safety coefficient) were studied. With the device of some UHV project taken as an example of project study, a practical calculation method that could be applied to analysis of earthquake resistance of UHV transformation devices was proposed, and the analysis result could be referred by related professional personnel.