Seismic performance and isolation design for 220kV surge arrester

In past earthquakes, a large number of surge arresters were damaged due to the low strength of materials. Compared with directly enlarging profiles of components, adopting isolation may be a more cost-effective way to improve the seismic performance of post electrical equipment. In this study, a numerical analysis of a representative 220 kV surge arrester is conducted. Since the stress safety factor of surge arrester under severe seismic inputs cannot satisfy the requirement of 1.67, the wire rope isolation is introduced. Based on the modified Bouc-wen model, the wire ropes are modeled as user-define elements. Then the arrangement and selection of wire ropes are determined based on the displacement and stress response of the isolated surge arrester. The results show that the wire rope isolation with proper configuration can effectively improve the seismic performance of surge arrester by reducing the stress while slightly increasing displacement response. Therefore, wire rope isolation is recommended for high voltage post equipment in seismic areas.