DSRR model for safety vulnerability assessment of power grid infrastructure in Henan Province China

Weak links in modern power grids can lead to cascading failures from isolated incidents, making the scientific assessment of grid and transmission line vulnerability essential for preventing large-scale blackouts. This study conceptualizes transmission lines as functionally critical infrastructure and develops a four-dimensional vulnerability assessment framework encompassing Danger, Susceptibility, Resistance, and Recoverability, taking into account natural environmental conditions, human disturbances, grid operational states, and emergency response capabilities. Distinct from conventional classification methods that primarily rely on structural topology or subjective judgment, this study adopts a hazard index-based approach and introduces an objective weighting mechanism using the entropy method to quantitatively evaluate and classify indicators across the four dimensions. A case study of 500 kV transmission lines in Henan Province, China, reveals that the composite vulnerability index of the province's critical power infrastructure reaches 57.2, indicating a high level of vulnerability. Among the transmission towers, 19.8% are classified at the "Higher" level and 40.6% at the "High" level. Considerable variation in Recoverability among towers significantly influences the overall vulnerability assessment results. Moreover, the distribution of susceptibility to various hazards and accidents shows strong spatial and temporal heterogeneity, closely related to seasonal factors and tower locations. Based on these findings, targeted strategies are proposed from the perspectives of line inspection and differentiated management, providing technical support for enhancing power grid resilience and improving disaster response efficiency.