Evaluation of power grid vulnerability indices accounting for wind power uncertainty

Abstract

As power systems undergo transformative changes driven by the integration of renewable energy sources, smart grids, and advanced control systems, evaluating vulnerabilities becomes paramount for ensuring resilience. This article introduces a robust framework for computing vulnerability indices, encompassing both cascading indices and spectral graph metrics. Cascading indices are initially computed. Then these indices are compared with pure and extended spectral graph metrics to rank the lines under N−1 contingency conditions. The research also delves into N−k contingency scenarios, examining the system’s vulnerability across various degrees of damage size. The influence of uncertainties related to wind power generation and load demand on line vulnerability is addressed. The Point Estimate Method (PEM) is employed to effectively accommodate these uncertainties offering a reduction in computational time. To validate the proposed framework and analysis methodologies, two case studies are employed—the IEEE 30-bus and 57-bus systems. It is found that the inclusion of wind power and load uncertainty affects the vulnerability of the system. While the impact on cascading indices is negligible for small networks, it becomes notable in the case of larger networks.