Seismic resilience evaluation and upgrading framework of UHV converter stations under optimal repair sequence

Seismic resilience of ultra-high-voltage converter stations (UHVCSs) has significant implications for reducing post-earthquake damages to power systems. In order to evaluate and improve the seismic resilience of UHVCSs, this article established a seismic resilience assessment framework based on optimal repair sequences. The framework involves a system operation model applicable to the topological characteristics of UHVCSs, and a pathway greedy method to efficiently identify the optimal repair sequence. First, the UHVCS system was partitioned according to the functional coupling relationship of the equipment, and then the system operation model was established based on the enumeration of equipment failure scenarios. Pathways of the system were identified by the connection matrix technique. Then, the optimal repair sequence was found by greedy algorithm at the pathway level. Finally, the statistical characteristics of the seismic resilience of the system were obtained through Monte Carlo sampling. Comparative studies were conducted on the multi-categories and -degrees of strengthening based on the proposed framework, finding upgrading strategies to enhance systems’ resilience. This framework avoids the impact of repair sequence uncertainty on resilience-related analysis and has computational feasibility, providing a reference for the formulation of seismic upgrading strategies for UHVCSs.