Wen Gao, Huayu Huang, Kaishun Xiahou, Yang Liu, Zhaoxi Liu, Q. H. Wu
The wide-area damping controllers (WADCs), which are essential for mitigating regional low-frequency oscillations, face cyber-physical security threats due to the vulnerability of wide-area measurement system to cyber attacks and wind power uncertainties. This paper introduces reachability analysis method to quantify the impact of varying-amplitude attacks and uncertain wind fluctuations on the performance of WADC. Firstly, considering wind farm integration and attack injection, a nonlinear power system model with multiple buses is constructed based on Kron reduction method to improve computational efficiency and mitigate the constraints imposed by algebraic constraints. Then, a zonotope-based polytope construction method is employed to effectively model the range of attack amplitudes and wind uncertainties. By conducting reachability analysis, the reachable set preserving the nonlinear characteristics of studied system is computed, which enables the quantification of the maximum fluctuation range of regional oscillations under the dual disturbances. Case studies are undertaken on two multimachine power systems with wind farm integration. The obtained results emphasize the efficacy of designed method, providing valuable insights into the magnitude of the impact that attacks exert on the operational characteristics of power system under various uncertain factors.