The Vulnerability Evaluation Model of Power Grid Based on the Protection-vulnerability-weighted Topological Model

Certain vulnerable links in the power grid have serious impacts on large-scale blackouts. To identify these vulnerable links effectively, a vulnerability evaluation method of power grid based on the protection-vulnerability-weighted topological model was proposed in this paper. Coordination degree of protections, fault severity of protections and protection vulnerability were defined, which were used to propose the concept of protection vulnerability of units in order to quantify the contribution of protection vulnerability to the fragility of units. Weighted topological model based on the protection vulnerability was established, and definitions of corresponding characteristic indices of the weighted topological model were given. Based upon all, an vulnerability evaluation method combining betweenness and protection vulnerability of units was presented. Results of a numerical example verified that the proposed method keeps a good effect of complex network theory in structural vulnerability identification, effectively considers the impact of the factor of vulnerability of protections on the vulnerability of units in the grid, and enhances the effect and accuracy of the identification of vulnerability, and thus demonstrate validity and prospect for application of the proposed method.