Dai Zebing

The effects of connection modes of transformation devices on seismic performance

The existing analysis on the seismic performance of transformation devices is mostly based on single device, while in practice; each transformation device is a power transformation system with bus-fixed supports, bus-sliding supports, bus-extension clamps being connected altogether using hard tubular bus bar. Connection modes between different devices may have possible effects on the seismic performance of the devices. Due to the situation that existing transformation devices may be easily damaged in earthquake and related seismic researches are not in-depth, a method of numerical simulation was utilized to analyze the relationship of the connection mode between transformation device and hard bus with the seismic performance of the device, and find out the optimal connection between transformation devices which was favorable for seismic performance, providing reasonable and scientific proof for the improvement of the seismic performance of transformation devices.

Analysis on the seismic energy dissipation response of the 500kV metallic oxide lightning arrester

The 500kV metallic oxide lightning arrester is a piece of porcelain electrical equipment and easy to be damaged under severe earthquake, because the equipment is made of brittle materials and can only subject to limited earthquake action. Damping devices can be mounted onto the porcelain electrical equipment to protect the equipment by absorbing large amount of earthquake energy. On that type of lightning arrester added with damping devices, the analyses of the seismic energy dissipation response of the equipment are carried out at different levels of seismic fortification intensity using the finite element analysis program ANSYS. At the same time, a contrast analysis on the seismic responses of anti-seismic and seismic energy dissipation of the lightning arrester was conducted. The results of the analysis showed that the arrester with damping device had good damping effect and it could be referred by the practical application of engineering projects.

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 engineers 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.